From Artem Tamazov:

Added: PW ATM 1:1, AAL5 SDU, AAL5 PDU support + BFD fix + PW ATM OAM fix

svn path=/trunk/; revision=28881

12 files changed, 2410 insertions, 691 deletions

diff --git a/epan/dissectors/Makefile.common b/epan/dissectors/Makefile.common
index 59a9cbdb06..092b939398 100644
--- a/epan/dissectors/Makefile.common
+++ b/epan/dissectors/Makefile.common
@@ -1151,6 +1151,7 @@ DISSECTOR_INCLUDES =	\
 	packet-ppi.h		\
 	packet-ppp.h	\
 	packet-pres.h	\
+	packet-pw-atm.h		\
 	packet-pw-common.h	\
 	packet-q931.h	\
 	packet-q932.h	\
diff --git a/epan/dissectors/packet-atm.c b/epan/dissectors/packet-atm.c
index e4585a1479..cc301de2b0 100644
--- a/epan/dissectors/packet-atm.c
+++ b/epan/dissectors/packet-atm.c
@@ -39,6 +39,7 @@
 #include "packet-tr.h"
 #include "packet-llc.h"
 #include "prefs.h"
+#include "packet-pw-atm.h"
 
 static int proto_atm = -1;
 static int hf_atm_aal = -1;
@@ -50,7 +51,6 @@ static int proto_ilmi = -1;
 static int proto_aal1 = -1;
 static int proto_aal3_4 = -1;
 static int proto_oamaal = -1;
-static int proto_atm_4717 = -1;
 
 static gint ett_atm = -1;
 static gint ett_atm_lane = -1;
@@ -934,6 +934,13 @@ dissect_reassembled_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
   tvbuff_t     *next_tvb;
   guint32      crc;
   guint32      calc_crc;
+  /* 
+   * ATM dissector is used as "sub-dissector" for ATM pseudowires.
+   * In such cases, pinfo->private_data is used to pass info from/to 
+   * PW dissector to ATM dissector. For decoding normal ATM traffic 
+   * private_data should be NULL.
+   */
+  gboolean     pseudowire_mode = (NULL != pinfo->private_data);
 
   /*
    * This is reassembled traffic, so the cell headers are missing;
@@ -965,20 +972,21 @@ dissect_reassembled_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
       break;
     }
   }
-  proto_tree_add_uint(atm_tree, hf_atm_vpi, tvb, 0, 0,
+  if (!pseudowire_mode) {
+    proto_tree_add_uint(atm_tree, hf_atm_vpi, tvb, 0, 0,
     		pinfo->pseudo_header->atm.vpi);
-  proto_tree_add_uint(atm_tree, hf_atm_vci, tvb, 0, 0,
+    proto_tree_add_uint(atm_tree, hf_atm_vci, tvb, 0, 0,
 		pinfo->pseudo_header->atm.vci);
 
-  /* Also show vpi/vci in info column */
-  if (check_col(pinfo->cinfo, COL_INFO))
-  {
+    /* Also show vpi/vci in info column */
+    if (check_col(pinfo->cinfo, COL_INFO))
+    {
       col_append_fstr(pinfo->cinfo, COL_INFO, " VPI=%u, VCI=%u",
                       pinfo->pseudo_header->atm.vpi,
                       pinfo->pseudo_header->atm.vci);
+    }
   }
 
-
   next_tvb = tvb;
   if (truncated) {
     /*
@@ -1120,7 +1128,13 @@ dissect_reassembled_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
             tvb_memcpy(next_tvb, octet, 0, sizeof(octet)); 
 
             decoded = TRUE;
-            if ((pntohs(octet) & 0xff) == PPP_IP)
+            if (octet[0] == 0xaa
+             && octet[1] == 0xaa
+             && octet[2] == 0x03) /* LLC SNAP as per RFC2684 */
+            {
+                call_dissector(llc_handle, next_tvb, pinfo, tree);
+            }
+            else if ((pntohs(octet) & 0xff) == PPP_IP)
             {
                 call_dissector(ppp_handle, next_tvb, pinfo, tree);
             }
@@ -1413,13 +1427,14 @@ get_header_err(const guint8 *cell_header)
     return UNCORRECTIBLE_ERROR;
 }
 
-static const value_string pt_vals[] = {
+const value_string atm_pt_vals[] = {
 	{ 0, "User data cell, congestion not experienced, SDU-type = 0" },
 	{ 1, "User data cell, congestion not experienced, SDU-type = 1" },
 	{ 2, "User data cell, congestion experienced, SDU-type = 0" },
 	{ 3, "User data cell, congestion experienced, SDU-type = 1" },
 	{ 4, "Segment OAM F5 flow related cell" },
 	{ 5, "End-to-end OAM F5 flow related cell" },
+	{ 6, "VC resource management cell" },
 	{ 0, NULL }
 };
 
@@ -1522,6 +1537,19 @@ static const value_string ft_ad_vals[] = {
 	{ 0, NULL }
 };
 
+
+/*
+ * Check for OAM cells.
+ * OAM F4 is VCI 3 or 4 and PT 0X0.
+ * OAM F5 is PT 10X.
+ */
+gboolean atm_is_oam_cell(const guint16 vci, const guint8 pt) 
+{
+	return  (((vci == 3 || vci == 4) && ((pt & 0x5) == 0)) 
+	 	|| ((pt & 0x6) == 0x4));
+}
+
+
 static void
 dissect_atm_cell(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                  proto_tree *atm_tree, guint aal, gboolean nni,
@@ -1540,8 +1568,10 @@ dissect_atm_cell(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
   gint         length;
   guint16      crc10;
   tvbuff_t     *next_tvb;
+  const pwatm_private_data_t * pwpd = pinfo->private_data;
 
-  if (!nni) {
+  if (NULL == pwpd) {
+    if (!nni) {
           /* 
            * FF: ITU-T I.361 (Section 2.2) defines the cell header format 
            * and encoding at UNI reference point as:
@@ -1565,7 +1595,7 @@ dissect_atm_cell(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
           octet = tvb_get_guint8(tvb, 1);
           vpi |= octet >> 4;
           proto_tree_add_uint(atm_tree, hf_atm_vpi, tvb, 0, 2, vpi);
-  } else {
+    } else {
           /* 
            * FF: ITU-T I.361 (Section 2.3) defines the cell header format 
            * and encoding at NNI reference point as:
@@ -1588,21 +1618,21 @@ dissect_atm_cell(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
           octet = tvb_get_guint8(tvb, 1);
           vpi |= (octet & 0xF0) >> 4;
           proto_tree_add_uint(atm_tree, hf_atm_vpi, tvb, 0, 2, vpi);
-  }
+    }
 
-  vci = (octet & 0x0F) << 12;
-  octet = tvb_get_guint8(tvb, 2);
-  vci |= octet << 4;
-  octet = tvb_get_guint8(tvb, 3);
-  vci |= octet >> 4;
-  proto_tree_add_uint(atm_tree, hf_atm_vci, tvb, 1, 3, vci);
-  pt = (octet >> 1) & 0x7;
-  proto_tree_add_text(atm_tree, tvb, 3, 1, "Payload Type: %s",
-        val_to_str(pt, pt_vals, "Unknown (%u)"));
-  proto_tree_add_text(atm_tree, tvb, 3, 1, "Cell Loss Priority: %s",
+    vci = (octet & 0x0F) << 12;
+    octet = tvb_get_guint8(tvb, 2);
+    vci |= octet << 4;
+    octet = tvb_get_guint8(tvb, 3);
+    vci |= octet >> 4;
+    proto_tree_add_uint(atm_tree, hf_atm_vci, tvb, 1, 3, vci);
+    pt = (octet >> 1) & 0x7;
+    proto_tree_add_text(atm_tree, tvb, 3, 1, "Payload Type: %s",
+         val_to_str(pt, atm_pt_vals, "Unknown (%u)"));
+    proto_tree_add_text(atm_tree, tvb, 3, 1, "Cell Loss Priority: %s",
 	(octet & 0x01) ? "Low priority" : "High priority");
-
-  if (!crc_stripped) {
+  
+    if (!crc_stripped) {
           /*
            * FF: parse the Header Error Check (HEC).
            */
@@ -1617,13 +1647,22 @@ dissect_atm_cell(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
           else
                   proto_item_append_text(ti, " (error in bit %d)", err);
           offset = 5;
-  } else {
+    } else {
           /*
            * FF: in some encapsulation modes (e.g. RFC 4717, ATM N-to-One
            * Cell Mode) the Header Error Check (HEC) field is stripped.
            * So we do nothing here.
            */
           offset = 4;
+    }
+  }
+  else
+  {
+    offset = 0; /* For PWs. Header is decoded by PW dissector.*/
+    pwpd = pinfo->private_data;
+    vpi = pwpd->vpi;
+    vci = pwpd->vci; 
+    pt  = pwpd->pti;
   }
 
   /*
@@ -1632,13 +1671,9 @@ dissect_atm_cell(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
    * Wiretap got from the file?
    */
   if (aal == AAL_USER) {
-	/*
-	 * OAM F4 is VCI 3 or 4 and PT 0X0.
-	 * OAM F5 is PT 10X.
-	 */
-	if (((vci == 3 || vci == 4) && ((pt & 0x5) == 0)) ||
-	    ((pt & 0x6) == 0x4))
-		aal = AAL_OAMCELL;
+    if (atm_is_oam_cell(vci,pt)) {
+      aal = AAL_OAMCELL;
+    }
   }
 
   switch (aal) {
@@ -1706,16 +1741,22 @@ dissect_atm_cell(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
     break;
 
   case AAL_OAMCELL:
-    if (check_col(pinfo->cinfo, COL_PROTOCOL))
-      col_set_str(pinfo->cinfo, COL_PROTOCOL, "OAM AAL");
-    if (check_col(pinfo->cinfo, COL_INFO))
-      col_clear(pinfo->cinfo, COL_INFO);
+    if (NULL == pwpd || pwpd->enable_fill_columns_by_atm_dissector)
+    {
+      if (check_col(pinfo->cinfo, COL_PROTOCOL))
+        col_set_str(pinfo->cinfo, COL_PROTOCOL, "OAM AAL");
+      if (check_col(pinfo->cinfo, COL_INFO))
+        col_clear(pinfo->cinfo, COL_INFO);
+    }
     ti = proto_tree_add_item(tree, proto_oamaal, tvb, offset, -1, FALSE);
     aal_tree = proto_item_add_subtree(ti, ett_oamaal);
     octet = tvb_get_guint8(tvb, offset);
-    if (check_col(pinfo->cinfo, COL_INFO))
-      col_add_fstr(pinfo->cinfo, COL_INFO, "%s",
+    if (NULL == pwpd || pwpd->enable_fill_columns_by_atm_dissector)
+    {
+      if (check_col(pinfo->cinfo, COL_INFO))
+        col_add_fstr(pinfo->cinfo, COL_INFO, "%s",
 		val_to_str(octet >> 4, oam_type_vals, "Unknown (%u)"));
+    }
     proto_tree_add_text(aal_tree, tvb, offset, 1, "OAM Type: %s",
 		val_to_str(octet >> 4, oam_type_vals, "Unknown (%u)"));
     switch (octet >> 4) {
@@ -1767,6 +1808,7 @@ dissect_atm_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 {
   proto_tree   *atm_tree = NULL;
   proto_item   *atm_ti = NULL;
+  gboolean     pseudowire_mode = (NULL != pinfo->private_data);
   
   if ( pinfo->pseudo_header->atm.aal == AAL_5 &&
   	pinfo->pseudo_header->atm.type == TRAF_LANE &&
@@ -1777,23 +1819,25 @@ dissect_atm_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
   if (check_col(pinfo->cinfo, COL_PROTOCOL))
     col_set_str(pinfo->cinfo, COL_PROTOCOL, "ATM");
 
-  switch (pinfo->pseudo_header->atm.channel) {
+  if (!pseudowire_mode) {
+    switch (pinfo->pseudo_header->atm.channel) {
 
-  case 0:
-    /* Traffic from DTE to DCE. */
-    if (check_col(pinfo->cinfo, COL_RES_DL_DST))
-      col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DCE");
-    if (check_col(pinfo->cinfo, COL_RES_DL_SRC))
-      col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DTE");
-    break;
+    case 0:
+      /* Traffic from DTE to DCE. */
+      if (check_col(pinfo->cinfo, COL_RES_DL_DST))
+        col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DCE");
+      if (check_col(pinfo->cinfo, COL_RES_DL_SRC))
+        col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DTE");
+      break;
 
-  case 1:
-    /* Traffic from DCE to DTE. */
-    if (check_col(pinfo->cinfo, COL_RES_DL_DST))
-      col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DTE");
-    if (check_col(pinfo->cinfo, COL_RES_DL_SRC))
-      col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DCE");
-    break;
+    case 1:
+      /* Traffic from DCE to DTE. */
+      if (check_col(pinfo->cinfo, COL_RES_DL_DST))
+        col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DTE");
+      if (check_col(pinfo->cinfo, COL_RES_DL_SRC))
+        col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DCE");
+      break;
+    }
   }
 
   if (check_col(pinfo->cinfo, COL_INFO)) {
@@ -1812,23 +1856,25 @@ dissect_atm_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
     atm_ti = proto_tree_add_protocol_format(tree, proto_atm, tvb, 0, 0, "ATM");
     atm_tree = proto_item_add_subtree(atm_ti, ett_atm);
 
-    switch (pinfo->pseudo_header->atm.channel) {
+    if (!pseudowire_mode) {
+      switch (pinfo->pseudo_header->atm.channel) {
 
-    case 0:
-      /* Traffic from DTE to DCE. */
-      proto_tree_add_text(atm_tree, tvb, 0, 0, "Channel: DTE->DCE");
-      break;
+      case 0:
+        /* Traffic from DTE to DCE. */
+        proto_tree_add_text(atm_tree, tvb, 0, 0, "Channel: DTE->DCE");
+        break;
 
-    case 1:
-      /* Traffic from DCE to DTE. */
-      proto_tree_add_text(atm_tree, tvb, 0, 0, "Channel: DCE->DTE");
-      break;
+      case 1:
+        /* Traffic from DCE to DTE. */
+        proto_tree_add_text(atm_tree, tvb, 0, 0, "Channel: DCE->DTE");
+        break;
 
-    default:
-      /* Sniffers shouldn't provide anything other than 0 or 1. */
-      proto_tree_add_text(atm_tree, tvb, 0, 0, "Channel: %u",
+      default:
+        /* Sniffers shouldn't provide anything other than 0 or 1. */
+        proto_tree_add_text(atm_tree, tvb, 0, 0, "Channel: %u",
  		pinfo->pseudo_header->atm.channel);
-      break;
+        break;
+      }
     }
 
     proto_tree_add_uint_format_value(atm_tree, hf_atm_aal, tvb, 0, 0,
@@ -1865,59 +1911,21 @@ dissect_atm_oam_cell(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 {
   proto_tree   *atm_tree = NULL;
   proto_item   *atm_ti = NULL;
+  gboolean     pseudowire_mode = (NULL != pinfo->private_data);
   
   if (check_col(pinfo->cinfo, COL_PROTOCOL))
     col_set_str(pinfo->cinfo, COL_PROTOCOL, "ATM");
 
-  if (tree) {
-    atm_ti = proto_tree_add_protocol_format(tree, proto_atm, tvb, 0, 0, "ATM");
-    atm_tree = proto_item_add_subtree(atm_ti, ett_atm);
+  if (!pseudowire_mode) {
+    if (tree) {
+      atm_ti = proto_tree_add_protocol_format(tree, proto_atm, tvb, 0, 0, "ATM");
+      atm_tree = proto_item_add_subtree(atm_ti, ett_atm);
+    }
   }
 
   dissect_atm_cell(tvb, pinfo, tree, atm_tree, AAL_OAMCELL, FALSE, FALSE);
 }
 
-/*
- * FF: this dissector is called directly from packet-pw-atm.c.
- * it checks pinfo->pw_atm_encap_type, pinfo->pw_atm_flags
- * in order to gather information about the used encapsulation
- * format (defined in RFC 4717).  The result (i.e. protocol tree
- * and cinfo) of this dissector should look like, as close as 
- * possible, to the legacy one (i.e. dissect_atm_[untruncated|oam_cell]).
- */
-static void
-dissect_atm_4717(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
-{
-        proto_tree *atm_tree = NULL;
-        proto_item *atm_ti = NULL;
-        
-        if (check_col(pinfo->cinfo, COL_PROTOCOL))
-                col_set_str(pinfo->cinfo, COL_PROTOCOL, "ATM");
-        
-        if (tree) {
-                atm_ti = proto_tree_add_protocol_format(tree, 
-                                                        proto_atm, 
-                                                        tvb, 0, 0, "ATM");
-                atm_tree = proto_item_add_subtree(atm_ti, ett_atm);
-        }
-
-        switch (pinfo->pw_atm_encap_type) {
-        case 1: /* ATM N-to-One Cell Mode */
-                if (check_col(pinfo->cinfo, COL_INFO)) {
-                        col_add_str(pinfo->cinfo, COL_INFO, "Unknown AAL");
-                        col_append_fstr(pinfo->cinfo, COL_INFO,
-                                        " (%u cell%s)",
-                                        pinfo->pw_atm_ncells,
-                                        pinfo->pw_atm_ncells == 1 ? "" : "s");
-                }
-                proto_item_set_len(atm_ti, 4);
-                dissect_atm_cell(tvb, pinfo, tree, atm_tree, 
-                                 AAL_UNKNOWN, TRUE, TRUE);
-                break;
-        default:
-                break;
-        }
-}
 
 void
 proto_register_atm(void)
@@ -1971,8 +1979,8 @@ proto_register_atm(void)
 
 	register_dissector("lane", dissect_lane, proto_atm_lane);
 	register_dissector("atm_untruncated", dissect_atm_untruncated, proto_atm);
+	register_dissector("atm_truncated", dissect_atm, proto_atm);
 	register_dissector("atm_oam_cell", dissect_atm_oam_cell, proto_oamaal);
-	register_dissector("atm_4717", dissect_atm_4717, proto_atm_4717);
 	
 	atm_module = prefs_register_protocol ( proto_atm, NULL );
 	prefs_register_bool_preference ( atm_module, "dissect_lane_as_sscop", "Dissect LANE as SSCOP",
@@ -1983,7 +1991,7 @@ proto_register_atm(void)
 void
 proto_reg_handoff_atm(void)
 {
-	dissector_handle_t atm_handle, atm_untruncated_handle, atm_4717_handle;
+	dissector_handle_t atm_handle, atm_untruncated_handle;
 
 	/*
 	 * Get handles for the Ethernet, Token Ring, Frame Relay, LLC,
@@ -2009,6 +2017,4 @@ proto_reg_handoff_atm(void)
 	    proto_atm);
 	dissector_add("wtap_encap", WTAP_ENCAP_ATM_PDUS_UNTRUNCATED,
 	    atm_untruncated_handle);
-
-	atm_4717_handle = create_dissector_handle(dissect_atm_4717, proto_atm);
 }
diff --git a/epan/dissectors/packet-atm.h b/epan/dissectors/packet-atm.h
index 2c6f04213a..466d54972a 100644
--- a/epan/dissectors/packet-atm.h
+++ b/epan/dissectors/packet-atm.h
@@ -27,4 +27,8 @@
 void capture_atm(const union wtap_pseudo_header *, const guchar *, int,
     packet_counts *);
 
+gboolean atm_is_oam_cell(const guint16 vci, const guint8 pt); /*For pw-atm dissector*/
+
+extern const value_string atm_pt_vals[]; /*For pw-atm dissector*/
+
 #endif
diff --git a/epan/dissectors/packet-bfd.c b/epan/dissectors/packet-bfd.c
index 2b82c4237e..7d564a26ac 100644
--- a/epan/dissectors/packet-bfd.c
+++ b/epan/dissectors/packet-bfd.c
@@ -685,6 +685,7 @@ void proto_register_bfd(void)
     proto_bfd = proto_register_protocol("Bidirectional Forwarding Detection Control Message",
                                         "BFD Control",
                                         "bfd");
+    register_dissector("bfd", dissect_bfd_control, proto_bfd);
 
     /* Required function calls to register the header fields and subtrees used */
     proto_register_field_array(proto_bfd, hf, array_length(hf));
diff --git a/epan/dissectors/packet-mpls.c b/epan/dissectors/packet-mpls.c
index 024fbe0d4f..6d77b1e803 100644
--- a/epan/dissectors/packet-mpls.c
+++ b/epan/dissectors/packet-mpls.c
@@ -58,6 +58,7 @@
 #include <epan/addr_resolv.h>
 #include "packet-ppp.h"
 #include "packet-mpls.h"
+#include "packet-pw-common.h"
 
 static gint proto_mpls = -1;
 static gint proto_pw_ach = -1;
@@ -92,6 +93,7 @@ enum mpls_filter_keys {
 static dissector_handle_t dissector_data;
 static dissector_handle_t dissector_ipv6;
 static dissector_handle_t dissector_ip;
+static dissector_handle_t dissector_bfd;
 static dissector_handle_t dissector_pw_eth_heuristic;
 static dissector_handle_t dissector_pw_fr;
 static dissector_handle_t dissector_pw_hdlc_nocw_fr;
@@ -100,6 +102,10 @@ static dissector_handle_t dissector_pw_eth_cw;
 static dissector_handle_t dissector_pw_eth_nocw;
 static dissector_handle_t dissector_pw_satop;
 static dissector_handle_t dissector_itdm;
+static dissector_handle_t dissector_mpls_pw_atm_n1_cw;
+static dissector_handle_t dissector_mpls_pw_atm_n1_nocw;
+static dissector_handle_t dissector_mpls_pw_atm_11_aal5pdu;
+static dissector_handle_t dissector_mpls_pw_atm_aal5_sdu;
 static dissector_handle_t dissector_pw_cesopsn;
 
 enum mpls_default_dissector_t {
@@ -113,6 +119,10 @@ enum mpls_default_dissector_t {
     ,MDD_MPLS_PW_ETH_NOCW
     ,MDD_MPLS_PW_GENERIC
     ,MDD_ITDM
+    ,MDD_MPLS_PW_ATM_N1_CW
+    ,MDD_MPLS_PW_ATM_N1_NOCW
+    ,MDD_MPLS_PW_ATM_11_OR_AAL5_PDU
+    ,MDD_MPLS_PW_ATM_AAL5_SDU
 };
 
 /* TODO the content of mpls_default_payload menu
@@ -123,12 +133,12 @@ enum mpls_default_dissector_t {
 static enum_val_t mpls_default_payload_defs[] = {
     {
         "pw satop"
-        ,"SAToP (no RTP support)"
+        ,pwc_longname_pw_satop
         ,MDD_PW_SATOP
     },
     {
         "pw cesopsn"
-        ,"CESoPSN basic NxDS0 mode (no RTP support)"
+        ,pwc_longname_pw_cesopsn
         ,MDD_PW_CESOPSN
     },
     {
@@ -172,6 +182,26 @@ static enum_val_t mpls_default_payload_defs[] = {
         ,MDD_ITDM
     },
     {
+        "mpls pw atm n_to_one cw"
+        ,pwc_longname_pw_atm_n1_cw
+        ,MDD_MPLS_PW_ATM_N1_CW
+    },
+    {
+        "mpls pw atm n_to_one no_cw"
+        ,pwc_longname_pw_atm_n1_nocw
+        ,MDD_MPLS_PW_ATM_N1_NOCW
+    },
+    {
+        "mpls pw atm one_to_one or aal5_pdu"
+        ,pwc_longname_pw_atm_11_or_aal5_pdu
+        ,MDD_MPLS_PW_ATM_11_OR_AAL5_PDU
+    },
+    {
+        "mpls pw atm aal5_sdu"
+        ,pwc_longname_pw_atm_aal5_sdu
+        ,MDD_MPLS_PW_ATM_AAL5_SDU
+    },
+    {
         NULL
         ,NULL
         ,-1
@@ -181,6 +211,9 @@ static enum_val_t mpls_default_payload_defs[] = {
 static int mpls_filter[MPLSF_MAX];
 
 static gint mpls_default_payload = 0;
+static gboolean mpls_pref_pwac_all_as_bfd_xipv4 = FALSE;
+static gboolean mpls_pref_pwac_0x0_as_bfd = FALSE;
+static gboolean mpls_pref_pwac_try_ppp = TRUE;
 
 static int hf_mpls_1st_nibble = -1;
 
@@ -236,6 +269,60 @@ static const value_string oam_defect_type_vals[] = {
     {0, NULL }
 };
 
+#if 0 /*not used yet*/
+/* 
+ * MPLS PW types 
+ * http://www.iana.org/assignments/pwe3-parameters
+ */
+static const value_string mpls_pw_types[] = {
+	{ 0x0001, "Frame Relay DLCI ( Martini Mode )"              }, 
+	{ 0x0002, "ATM AAL5 SDU VCC transport"                     },
+	{ 0x0003, "ATM transparent cell transport"                 },
+	{ 0x0004, "Ethernet Tagged Mode"                           },
+	{ 0x0005, "Ethernet"                                       },
+	{ 0x0006, "HDLC"                                           },
+	{ 0x0007, "PPP"                                            },
+	{ 0x0008, "SONET/SDH Circuit Emulation Service Over MPLS"  },
+	{ 0x0009, "ATM n-to-one VCC cell transport"                },
+	{ 0x000A, "ATM n-to-one VPC cell transport"                },
+	{ 0x000B, "IP Layer2 Transport"                            },
+	{ 0x000C, "ATM one-to-one VCC Cell Mode"                   },
+	{ 0x000D, "ATM one-to-one VPC Cell Mode"                   },
+	{ 0x000E, "ATM AAL5 PDU VCC transport"                     },
+	{ 0x000F, "Frame-Relay Port mode"                          },
+	{ 0x0010, "SONET/SDH Circuit Emulation over Packet"        },
+	{ 0x0011, "Structure-agnostic E1 over Packet"              },
+	{ 0x0012, "Structure-agnostic T1 (DS1) over Packet"        },
+	{ 0x0013, "Structure-agnostic E3 over Packet"              },
+	{ 0x0014, "Structure-agnostic T3 (DS3) over Packet"        },
+	{ 0x0015, "CESoPSN basic mode"                             },
+	{ 0x0016, "TDMoIP AAL1 Mode"                               },
+	{ 0x0017, "CESoPSN TDM with CAS"                           },
+	{ 0x0018, "TDMoIP AAL2 Mode"                               },
+	{ 0x0019, "Frame Relay DLCI"                               },
+	{ 0x001A, "ROHC Transport Header-compressed Packets"       },/*[RFC4995][RFC4901]*/
+	{ 0x001B, "ECRTP Transport Header-compressed Packets"      },/*[RFC3545][RFC4901]*/
+	{ 0x001C, "IPHC Transport Header-compressed Packets"       },/*[RFC2507][RFC4901]*/
+	{ 0x001D, "cRTP Transport Header-compressed Packets"       },/*[RFC2508][RFC4901]*/
+	{ 0x001E, "ATM VP Virtual Trunk"                           },/*[MFA9]*/
+	{ 0x001F, "Reserved"                                       },/*[Bryant]  2008-04-17*/
+	{ 0, NULL }
+};
+#endif
+
+/* 
+ * MPLS PW Associated Channel Types
+ * as per http://www.iana.org/assignments/pwe3-parameters
+ * and http://tools.ietf.org/html/draft-ietf-pwe3-vccv-bfd-05 clause 3.2 
+ */
+static const value_string mpls_pwac_types[] = {
+        { 0x0007, "BFD Control, PW-ACH-encapsulated (BFD Without IP/UDP Headers)" },
+	{ 0x0021, "IPv4 packet" },
+	{ 0x0057, "IPv6 packet" },
+	{ 0, NULL }
+};
+
+
 static dissector_table_t ppp_subdissector_table;
 static dissector_table_t mpls_subdissector_table;
 
@@ -289,20 +376,49 @@ dissect_pw_ach(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
                                    tvb, 0, 1, ver, "Version: %d", ver);
         ti = proto_tree_add_uint_format(mpls_pw_ach_tree, hf_mpls_pw_ach_res,
                                         tvb, 1, 1, res, "Reserved: 0x%02x", res);
-        PROTO_ITEM_SET_HIDDEN(ti);
         if (res != 0)
             proto_tree_add_text(mpls_pw_ach_tree, tvb, 1, 1,
                 "Error: this byte is reserved and must be 0");
+        else
+            PROTO_ITEM_SET_HIDDEN(ti);
         proto_tree_add_uint_format(mpls_pw_ach_tree, hf_mpls_pw_ach_channel_type,
                                    tvb, 2, 2, channel_type,
                                    "Channel Type: %s (0x%04x)",
-                                   val_to_str(channel_type, ppp_vals, "Unknown"),
+                                   val_to_str(channel_type, mpls_pwac_types, "Unknown"),
                                               channel_type);
     }
     next_tvb = tvb_new_subset(tvb, 4, -1, -1);
-    if (!dissector_try_port(ppp_subdissector_table, channel_type, 
+
+    if (0x21 == channel_type /*IPv4, RFC4385 clause 6.*/) 
+    {
+        call_dissector(dissector_ip, next_tvb, pinfo, tree);
+    } 
+    else if (0x7 == channel_type /*PWACH-encapsulated BFD, draft-ietf-pwe3-vccv-bfd-05 3.2*/
+            || mpls_pref_pwac_all_as_bfd_xipv4)
+    {
+        call_dissector(dissector_bfd, next_tvb, pinfo, tree);
+    }
+    else if (0x57 == channel_type /*IPv6, RFC4385 clause 6.*/)
+    {
+        call_dissector(dissector_ipv6, next_tvb, pinfo, tree);
+    }
+    else if (0x0 == channel_type && mpls_pref_pwac_0x0_as_bfd)
+    {
+        call_dissector(dissector_bfd, next_tvb, pinfo, tree);
+    }
+    else if (mpls_pref_pwac_try_ppp)
+    {
+        /* XXX perhaps this code should be reconsidered */
+        /* non-standard extension, therefore controlled by option*/
+        /* appeared in revision 10862 from Carlos M. Pignataro */
+        if (!dissector_try_port(ppp_subdissector_table, channel_type, 
                             next_tvb, pinfo, tree)) {
             call_dissector(dissector_data, next_tvb, pinfo, tree);
+        }
+    }
+    else
+    {
+        call_dissector(dissector_data, next_tvb, pinfo, tree);
     }
 }
 
@@ -683,8 +799,20 @@ dissect_mpls(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
         case MDD_ITDM:
                call_dissector(dissector_itdm, next_tvb, pinfo, tree);
                break;
-        default: /*fallthrough*/
-        case MDD_MPLS_PW_GENERIC:
+        case MDD_MPLS_PW_ATM_N1_CW:
+               call_dissector(dissector_mpls_pw_atm_n1_cw, next_tvb, pinfo, tree);
+               break;
+        case MDD_MPLS_PW_ATM_N1_NOCW:
+               call_dissector(dissector_mpls_pw_atm_n1_nocw, next_tvb, pinfo, tree);
+               break;
+        case MDD_MPLS_PW_ATM_11_OR_AAL5_PDU:
+               call_dissector(dissector_mpls_pw_atm_11_aal5pdu, next_tvb, pinfo, tree);
+               break;
+        case MDD_MPLS_PW_ATM_AAL5_SDU:
+               call_dissector(dissector_mpls_pw_atm_aal5_sdu, next_tvb, pinfo, tree);
+               break;
+        default: /*fallthrough*/        
+	case MDD_MPLS_PW_GENERIC:
                dissect_pw_mcw(next_tvb, pinfo, tree);
                break;
         }
@@ -806,6 +934,35 @@ proto_register_mpls(void)
 					&mpls_default_payload,
 					mpls_default_payload_defs,
 					FALSE );
+	prefs_register_bool_preference(module_mpls
+		,"mplspref.pwac_0x0_as_bfd"
+		,"Assume PWAC Channel Type 0x0 is raw BFD"
+		,"draft-ietf-pwe3-vccv-bfd-05 states that PWAC Channel Type 0x07 must be used"
+		" when VCCV carries PW-ACH-encapsulated BFD (i.e., BFD without IP/UDP Headers, or \"raw\" BFD)"
+		"\n\n"
+		"Legacy or buggy devices may not comply to this and use Channel Type 0x0 for BFD."
+		" Enable this preference to decode such BFD traffic."
+		" Disable for standard behavior of PWAC dissector (default)."
+		,&mpls_pref_pwac_0x0_as_bfd);
+	prefs_register_bool_preference(module_mpls
+		,"mplspref.pwac_all_as_bfd_xip"
+		,"Assume that all PWAC Channel Types (except 0x21) are raw BFD"
+		,"draft-ietf-pwe3-vccv-bfd-05 states that PWAC Channel Type 0x07 must be used"
+		" when VCCV carries PW-ACH-encapsulated BFD (i.e., \"raw\" BFD)"
+		"\n\n"
+		"Legacy or buggy devices may not comply to this and use voluntary Channel Type for BFD."
+		" Enable this preference to decode all PWAC Channel Types as raw BFD,"
+		" except Channel Type 0x21 (IPv4)."
+		" Disable for standard behavior of PWAC dissector (default)."
+		,&mpls_pref_pwac_all_as_bfd_xipv4);
+	prefs_register_bool_preference(module_mpls
+		,"mplspref.pwac_try_ppp"
+		,"As a last resort, try to decode PWAC payloads as PPP traffic"
+		,"Legacy devices may use MPLS PW Associated Channel for PPP traffic."
+		"\n\n"
+		"Enable this preference to allow PWAC dissector to try PPP,"
+		" if no other suitable dissector found (default)."
+		,&mpls_pref_pwac_try_ppp);
 }
 
 void
@@ -836,6 +993,7 @@ proto_reg_handoff_mpls(void)
 		dissector_data 			= find_dissector("data");
 		dissector_ipv6 			= find_dissector("ipv6");
 		dissector_ip 			= find_dissector("ip");
+		dissector_bfd			= find_dissector("bfd");
 		dissector_pw_eth_heuristic 	= find_dissector("pw_eth_heuristic");
 		dissector_pw_fr 		= find_dissector("pw_fr");
 		dissector_pw_hdlc_nocw_fr 	= find_dissector("pw_hdlc_nocw_fr");
@@ -844,6 +1002,10 @@ proto_reg_handoff_mpls(void)
 		dissector_pw_eth_nocw 		= find_dissector("pw_eth_nocw");
 		dissector_pw_satop 		= find_dissector("pw_satop");
 		dissector_itdm 			= find_dissector("itdm");
+		dissector_mpls_pw_atm_n1_cw	= find_dissector("mpls_pw_atm_n1_cw");
+		dissector_mpls_pw_atm_n1_nocw	= find_dissector("mpls_pw_atm_n1_nocw");
+		dissector_mpls_pw_atm_11_aal5pdu= find_dissector("mpls_pw_atm_11_or_aal5_pdu");
+		dissector_mpls_pw_atm_aal5_sdu	= find_dissector("mpls_pw_atm_aal5_sdu");
 		dissector_pw_cesopsn		= find_dissector("pw_cesopsn");
 
 		initialized = TRUE;
diff --git a/epan/dissectors/packet-pw-atm.c b/epan/dissectors/packet-pw-atm.c
index c281b70dd5..bec5e81966 100644
--- a/epan/dissectors/packet-pw-atm.c
+++ b/epan/dissectors/packet-pw-atm.c
@@ -1,9 +1,10 @@
 /* packet-pw-atm.c
  * Routines for ATM PW dissection: it should be conform to RFC 4717.
  *
- * Copyright 2009 _FF_
+ * Copyright 2009 _FF_, _ATA_
  *
  * Francesco Fondelli <francesco dot fondelli, gmail dot com>
+ * Artem Tamazov <artem [dot] tamazov [at] tellabs [dot] com>
  *
  * $Id$
  *
@@ -30,15 +31,9 @@
     DONE:
         - ATM N-to-One Cell Mode (with CW)
         - ATM N-to-One Cell Mode (no CW)
-    TODO:
         - ATM One-to-One Cell Mode
         - ATM AAL5 SDU Mode
         - ATM AAL5 PDU Mode
-
-        Please pick an item from the TODO list, move code out of #if 0
-        (see below) and implement a dissector for the given encapsulation
-        mode.  The N-to-One Cell Mode is the only mandatory encap
-        mode.  One-to-One/SDU/PDU modes are optional.
 */
 
 #ifdef HAVE_CONFIG_H
@@ -50,541 +45,1968 @@
 #include <string.h>
 #include <glib.h>
 #include <epan/packet.h>
+#include <epan/expert.h>
+#include <epan/prefs.h>
 
+#include <wiretap/wtap.h> /*for atm pseudo header*/
 #include "packet-mpls.h"
+#include "packet-atm.h"
+#include "packet-pw-atm.h"
+#include "packet-pw-common.h"
 
-static gint proto_pw_atm_n2o_cw = -1;
-static gint proto_pw_atm_n2o_nocw = -1;
-#if 0
-static gint proto_pw_atm_o2o_cw = -1;
-static gint proto_pw_atm_o2o_nocw = -1;
-static gint proto_pw_atm_aal5_pdu_cw = -1;
-static gint proto_pw_atm_aal5_pdu_nocw = -1;
-static gint proto_pw_atm_aal5_sdu_cw = -1;
-static gint proto_pw_atm_aal5_sdu_nocw = -1;
-#endif
+static gint proto_n1_nocw = -1;
+static gint proto_n1_cw = -1;
+static gint proto_11_or_aal5_pdu = -1;
+static gint proto_aal5_sdu = -1;
+/* subordinate dissectors: */
+static gint proto_control_word = -1;
+static gint proto_cell_header = -1;
+static gint proto_cell = -1;
 
-static gint ett_pw_atm = -1;
-
-static int hf_pw_atm_n2o_cw = -1;
-static int hf_pw_atm_n2o_cw_flags = -1;
-static int hf_pw_atm_n2o_cw_length = -1;
-static int hf_pw_atm_n2o_cw_sequence_number = -1;
-static int hf_pw_atm_n2o_nocw = -1;
-#if 0
-static int hf_pw_atm_o2o_cw = -1;
-static int hf_pw_atm_o2o_cw_sequence_number = -1;
-static int hf_pw_atm_o2o_cw_flags = -1;
-static int hf_pw_atm_o2o_cw_flags_m = -1;
-static int hf_pw_atm_o2o_cw_flags_v = -1;
-static int hf_pw_atm_o2o_cw_flags_res = -1;
-static int hf_pw_atm_o2o_cw_flags_pti = -1;
-static int hf_pw_atm_o2o_cw_flags_c = -1;
-static int hf_pw_atm_o2o_nocw = -1;
-static int hf_pw_atm_aal5_pdu_cw = -1;
-static int hf_pw_atm_aal5_pdu_cw_sequence_number = -1;
-static int hf_pw_atm_aal5_pdu_nocw = -1;
-static int hf_pw_atm_aal5_sdu_cw = -1;
-static int hf_pw_atm_aal5_sdu_cw_sequence_number = -1;
-static int hf_pw_atm_aal5_sdu_nocw = -1;
-#endif
+static gint ett_encaps = -1;
+static gint ett_cw = -1;
+static gint ett_cell_header = -1;
+static gint ett_cell = -1;
+
+static int hf_pw_type_n1_cw = -1;
+static int hf_pw_type_n1_nocw = -1;
+static int hf_pw_type_11_vcc = -1;
+static int hf_pw_type_11_vpc = -1;
+static int hf_pw_type_aal5_sdu = -1;
+static int hf_pw_type_aal5_pdu = -1;
+
+static int hf_cell_h_vpi = -1;
+static int hf_cell_h_vci = -1;
+static int hf_cell_h_pti = -1;
+static int hf_cell_h_clp = -1;
+static int hf_cell_h_m = -1;
+static int hf_cell_h_v = -1;
+static int hf_cell_h_rsv = -1;
+static int hf_aal5_pdu_rsv = -1;
+static int hf_aal5_pdu_u = -1;
+static int hf_aal5_pdu_e = -1;
+
+static int hf_cw_bits03 = -1;
+static int hf_pref_cw_rsv = -1;
+static int hf_generic_cw_rsv = -1;
+static int hf_pref_cw_flags = -1;
+static int hf_pref_cw_a5s_t = -1;
+static int hf_pref_cw_a5s_e = -1;
+static int hf_pref_cw_a5s_c = -1;
+static int hf_pref_cw_a5s_u = -1;
+static int hf_pref_cw_len = -1;
+static int hf_pref_cw_rsvlen = -1;
+static int hf_cw_seq = -1;
+static int hf_n1_cw_ncells = -1;
+static int hf_n1_nocw_ncells = -1;
+static int hf_11_ncells = -1;
+static int hf_gen_cw_atmbyte = -1;
+static int hf_cell_payload_len = -1;
+
+static dissector_handle_t dh_cell;
+static dissector_handle_t dh_cell_header;
+static dissector_handle_t dh_control_word;
+static dissector_handle_t dh_atm_truncated;
+static dissector_handle_t dh_atm_untruncated;
+static dissector_handle_t dh_atm_oam_cell;
+static dissector_handle_t dh_padding;
+static dissector_handle_t dh_data;
+
+#define PTI_IS_ADMIN(pti) ((pti) == 4 || (pti) == 5 || (pti) == 6)  /*see atm_pt_vals[]*/
+
+#define MODE_11(mode) 			(PWATM_MODE_11_VCC == (mode) || PWATM_MODE_11_VPC == (mode))
+#define MODE_N1(mode) 			(PWATM_MODE_N1_NOCW == (mode)|| PWATM_MODE_N1_CW == (mode))
+#define MODE_11_OR_AAL5_PDU(mode)   	(MODE_11(mode) || PWATM_MODE_AAL5_PDU == (mode))
+
+#define VALUE_SELECTOR_VPC_VCC_PDU(mode,val_vpc,val_vcc,val_pdu)\
+	((PWATM_MODE_11_VPC == (mode))				\
+		? (val_vpc)					\
+		: ((PWATM_MODE_11_VCC == (mode))		\
+			? (val_vcc)				\
+			: ((PWATM_MODE_AAL5_PDU == (mode))	\
+				? (val_pdu)			\
+				: 0				\
+			  )					\
+		  )						\
+	)
+
+#define UPDATE_CUMULATIVE_VALUE(cumulative_val,new_val)\
+	do\
+	{\
+		if (-2 >= (cumulative_val))\
+		{\
+		}\
+		else if (-1 == (cumulative_val))\
+		{\
+			(cumulative_val) = (new_val);\
+		}\
+		else if ((new_val) != (cumulative_val))\
+		{\
+			(cumulative_val) = -2;\
+		}\
+	}\
+	while(0)
+
+#define SIZEOF_ATM_CELL_PAYLOAD 48
+#define SIZEOF_N1_PW_CELL_HEADER 4
+#define SIZEOF_11_VCC_PW_CELL_HEADER 1
+#define SIZEOF_11_VPC_PW_CELL_HEADER 3
+#define SIZEOF_N1_PW_CELL	(SIZEOF_ATM_CELL_PAYLOAD+SIZEOF_N1_PW_CELL_HEADER)
+#define SIZEOF_11_VCC_PW_CELL	(SIZEOF_ATM_CELL_PAYLOAD+SIZEOF_11_VCC_PW_CELL_HEADER)
+#define SIZEOF_11_VPC_PW_CELL	(SIZEOF_ATM_CELL_PAYLOAD+SIZEOF_11_VPC_PW_CELL_HEADER)
+
+const char pwc_longname_pw_atm_n1_cw[] = "MPLS PW ATM N-to-One encapsulation, with CW";
+const char pwc_longname_pw_atm_n1_nocw[] = "MPLS PW ATM N-to-One encapsulation, no CW";
+const char pwc_longname_pw_atm_11_or_aal5_pdu[] = "MPLS PW ATM One-to-One or AAL5 PDU encapsulation";
+const char pwc_longname_pw_atm_aal5_sdu[] = "MPLS PW ATM AAL5 CPCS-SDU mode encapsulation";
 
-static dissector_handle_t data_h;
-static dissector_handle_t atm_h;
+static const char longname_pw_atm_11_vcc[] = "MPLS PW ATM One-to-One VCC Cell Transport";
+static const char longname_pw_atm_11_vpc[] = "MPLS PW ATM One-to-One VPC Cell Transport";
+static const char longname_pw_atm_aal5_pdu[] = "MPLS PW ATM AAL5 PDU encapsulation";
 
-/* ATM One-to-One Cell Mode bits in "ATM Specific" CW field */
-#define PW_ATM_O2O_CW_M   0x80
-#define PW_ATM_O2O_CW_V   0x40
-#define PW_ATM_O2O_CW_RES 0x30
-#define PW_ATM_O2O_CW_PTI 0x0E
-#define PW_ATM_O2O_CW_C   0x01
+static const char shortname_n1_cw[] = "MPLS PW ATM N:1 CW";
+static const char shortname_n1_nocw[] = "MPLS PW ATM N:1 no CW";
+static const char shortname_11_or_aal5_pdu[] = "MPLS PW ATM 1:1 / AAL5 PDU";
+static const char shortname_11_vpc[] = "MPLS PW ATM 1:1 VPC";
+static const char shortname_11_vcc[] = "MPLS PW ATM 1:1 VCC";
+static const char shortname_aal5_sdu[] = "MPLS PW ATM AAL5 SDU";
+static const char shortname_aal5_pdu[] = "MPLS PW ATM AAL5 PDU";
 
-static void
-dissect_pw_atm_n2o_cw(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+/*
+ * These options are needed to support Nokia AXE and stuff alike.
+ * Note that these options will affect PW type auto-guessing, if such heuristic
+ * implemented in the future.
+ */
+static gboolean pref_n1_cw_allow_cw_length_nonzero	= FALSE;
+static gboolean pref_n1_cw_extend_cw_length_with_rsvd	= FALSE;
+static gboolean pref_aal5_sdu_allow_cw_length_nonzero	= FALSE;
+static gboolean pref_aal5_sdu_extend_cw_length_with_rsvd= FALSE;
+
+
+static
+int pw_cell_size(const pwatm_mode_t mode, const pwatm_submode_t submode)
 {
-        proto_tree *pw_atm_tree = NULL;
-        proto_item *ti = NULL;
-        tvbuff_t *next_tvb = NULL;
-        guint16 sequence_number = 0;
-        guint8 flags = 0;
-        guint8 length = 0;
-        guint16 ncells = 0;
-        guint16 remains = 0;
-        guint16 i = 0;
-
-        if (tvb_reported_length_remaining(tvb, 0) < 4) {
-                if (tree)
-                        proto_tree_add_text(tree, tvb, 0, -1, 
-                                            "Error processing Message");
-                return;
-        }
-
-        if (tree) {
-                ti = proto_tree_add_boolean(tree, hf_pw_atm_n2o_cw, 
-                                            tvb, 0, 0, TRUE);
-                PROTO_ITEM_SET_HIDDEN(ti);
-                ti = proto_tree_add_item(tree, proto_pw_atm_n2o_cw, 
-                                         tvb, 0, 4, FALSE);
-                pw_atm_tree = proto_item_add_subtree(ti, ett_pw_atm);
-                if (pw_atm_tree == NULL)
-                        return;
-
-                flags = tvb_get_guint8(tvb, 0) & 0x0F;
-                proto_tree_add_uint_format(
-                        pw_atm_tree,
-                        hf_pw_atm_n2o_cw_flags,
-                        tvb, 0, 1, flags,
-                        "Flags: 0x%02x",
-                        flags);
-
-                length = tvb_get_guint8(tvb, 1) & 0x3F;
-                proto_tree_add_uint_format(
-                        pw_atm_tree,
-                        hf_pw_atm_n2o_cw_length,
-                        tvb, 1, 1, length,
-                        "Length: %u",
-                        flags);
-
-                sequence_number = tvb_get_ntohs(tvb, 2);
-                proto_tree_add_uint_format(
-                        pw_atm_tree,
-                        hf_pw_atm_n2o_cw_sequence_number,
-                        tvb, 2, 2, sequence_number,
-                        "Sequence Number: %u",
-                        sequence_number);
-        }
-
-        /* FF: pass info to the ATM dissector, see packet_info.h for details */
-        pinfo->pw_atm_encap_type = 1;
-
-        /*
-         * FF: RFC 4717: "The number of cells encapsulated in a particular 
-         * frame can be inferred by the frame length" but "if the control 
-         * word is used, then the flag and length bits in the control word 
-         * are not used [and must be set to 0]" so... no reported_length in
-         * tvb_new_subset().
-         */
-        ncells = tvb_length_remaining(tvb, 4) / 52;
-        pinfo->pw_atm_ncells = ncells;
-        remains = tvb_length_remaining(tvb, 4) % 52;
-
-        for (i = 0; i < ncells; i++) {
-                next_tvb = tvb_new_subset(tvb, 
-                                          4 + (i * 52), 
-                                          52, 
-                                          -1);
-                call_dissector(atm_h, next_tvb, pinfo, tree);
-        }
-
-        /* 
-         * FF: RFC 4717 "if the pseudowire traverses a network link that 
-         * requires a minimum frame size, with a minimum frame size of 64 
-         * octets, then such links will apply padding to the pseudowire PDU 
-         * to reach its minimum frame size" or this is a malformed PDU,
-         * anyway...
-         */
-        if (remains) {
-                next_tvb = tvb_new_subset(tvb,
-                                          4 + (i * 52), 
-                                          remains, 
-                                          -1);
-                call_dissector(data_h, next_tvb, pinfo, tree);
-        }
+	switch(mode)
+	{
+	case PWATM_MODE_N1_NOCW:
+	case PWATM_MODE_N1_CW:
+		return SIZEOF_N1_PW_CELL;
+	case PWATM_MODE_11_VCC:
+		return SIZEOF_11_VCC_PW_CELL;
+	case PWATM_MODE_11_VPC:
+		return SIZEOF_11_VPC_PW_CELL;
+	case PWATM_MODE_AAL5_PDU:
+		/* AAL5 PDU size is n*48 bytes */
+		return SIZEOF_ATM_CELL_PAYLOAD;
+	case PWATM_MODE_AAL5_SDU:
+		if (PWATM_SUBMODE_ADMIN_CELL == submode)
+		{
+			return SIZEOF_N1_PW_CELL; /*n:1 encapsulation is used for admin cells*/
+		}
+		else
+		{
+			DISSECTOR_ASSERT_NOT_REACHED();
+			return 0;
+		}
+	default:
+		DISSECTOR_ASSERT_NOT_REACHED();
+		return 0;
+	}
 }
 
-static void
-dissect_pw_atm_n2o_nocw(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+static
+int pw_cell_header_size(const pwatm_mode_t mode, const pwatm_submode_t submode)
 {
-        proto_item *ti = NULL;
-        tvbuff_t *next_tvb = NULL;
-        guint16 ncells = 0;
-        guint16 remains = 0;
-        guint16 i = 0;
-
-        /* 
-         * FF: all comments in dissect_pw_atm_n2o_cw() apply here
-         * as well, thus not repeated.
-         */
-
-        if (tvb_reported_length_remaining(tvb, 0) < 52) {
-                if (tree)
-                        proto_tree_add_text(tree, tvb, 0, -1, 
-                                            "Error processing Message");
-                return;
-        }
-
-        if (tree) {
-                ti = proto_tree_add_boolean(tree, hf_pw_atm_n2o_nocw, 
-                                            tvb, 0, 0, TRUE);
-                PROTO_ITEM_SET_HIDDEN(ti);
-        }
-
-        pinfo->pw_atm_encap_type = 1;
-        ncells = tvb_length_remaining(tvb, 0) / 52;
-        pinfo->pw_atm_ncells = ncells;
-        remains = tvb_length_remaining(tvb, 0) % 52;
-
-        for (i = 0; i < ncells; i++) {
-                next_tvb = tvb_new_subset(tvb, 
-                                          (i * 52), 
-                                          52, 
-                                          -1);
-                call_dissector(atm_h, next_tvb, pinfo, tree);
-        }
-
-        if (remains) {
-                next_tvb = tvb_new_subset(tvb,
-                                          (i * 52), 
-                                          remains, 
-                                          -1);
-                call_dissector(data_h, next_tvb, pinfo, tree);
-        }
+	switch(mode)
+	{
+	case PWATM_MODE_N1_NOCW:
+	case PWATM_MODE_N1_CW:
+		return SIZEOF_N1_PW_CELL_HEADER;
+	case PWATM_MODE_11_VCC:
+		return SIZEOF_11_VCC_PW_CELL_HEADER;
+	case PWATM_MODE_11_VPC:
+		return SIZEOF_11_VPC_PW_CELL_HEADER;
+	case PWATM_MODE_AAL5_SDU:
+		if (PWATM_SUBMODE_ADMIN_CELL == submode)
+		{
+			return SIZEOF_N1_PW_CELL_HEADER; /*n:1 encapsulation is used for admin cells*/
+		}
+		else
+		{
+			DISSECTOR_ASSERT_NOT_REACHED();
+			return 0;
+		}
+	case PWATM_MODE_AAL5_PDU: /*not applicable*/
+	default:
+		DISSECTOR_ASSERT_NOT_REACHED();
+		return 0;
+	}
 }
 
-#if 0
-static void
-dissect_pw_atm_o2o_cw(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+static
+int number_of_cells(const pwatm_mode_t mode
+		,const pwatm_submode_t submode
+		,const gint payload_size
+		,gint* const remainder_size)
 {
-        (void)tvb;
-        (void)pinfo;
-        (void)tree;
+	int cells;	
+	assert(payload_size >= 0);
+	assert(remainder_size != NULL);
+	
+	switch(mode)
+	{
+	case PWATM_MODE_N1_NOCW:
+	case PWATM_MODE_N1_CW:
+	case PWATM_MODE_11_VCC:
+	case PWATM_MODE_11_VPC:
+	case PWATM_MODE_AAL5_PDU:
+		cells = payload_size / pw_cell_size(mode,submode);
+		*remainder_size = payload_size - (cells * pw_cell_size(mode,submode));
+		return cells;
+	case PWATM_MODE_AAL5_SDU:
+		if (PWATM_SUBMODE_ADMIN_CELL == submode)
+		{
+			cells = payload_size / pw_cell_size(mode,submode);
+			if (cells > 1) cells = 1; /*max. 1 admin cell may be present in aal5 sdu mode */
+			*remainder_size = payload_size - (cells * pw_cell_size(mode,submode));
+			return cells;
+		}
+		else
+		{
+			/*not applicable*/
+		}
+		/*fallthrough*/
+	default:
+		DISSECTOR_ASSERT_NOT_REACHED();
+		*remainder_size = payload_size;
+		return 0;
+	}
+	
 }
 
-static void
-dissect_pw_atm_o2o_nocw(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+
+static
+void col_append_pw_info(packet_info * pinfo
+	,const int payload_size
+	,const int cells
+	,const int padding_size)
 {
-        (void)tvb;
-        (void)pinfo;
-        (void)tree;
+	pwatm_private_data_t* pd;
+	assert(pinfo != NULL);
+
+	pd = pinfo->private_data;
+	assert(pd != NULL);
+
+	if (pd->props & PWC_ANYOF_CW_BAD)
+	{
+		col_append_str(pinfo->cinfo, COL_INFO, "CW:Bad");
+	}
+	
+	if (pd->props & PWC_PAY_SIZE_BAD)
+	{
+		if (pd->props & PWC_ANYOF_CW_BAD)
+		{
+			col_append_str(pinfo->cinfo, COL_INFO, ", ");
+		}
+		col_append_str(pinfo->cinfo, COL_INFO, "Payload size:Bad, ");
+		col_append_fstr(pinfo->cinfo, COL_INFO, "%d byte%s"
+			,(int)payload_size
+			,plurality(payload_size,"","s"));
+	}
+	
+	if (pd->props == 0) /*omit "atm cells" etc if something is wrong*/
+	{
+		/* number of cells may be not known */
+		if (cells >=0)
+			col_append_fstr(pinfo->cinfo, COL_INFO, "%d ATM cell%s"
+				,cells
+				,plurality(cells,"","s"));
+		/*
+		 * Display ATM-specific attributes which are the same
+		 * across all the cells in the pw packet.
+		 * Meanings of values:
+		 *   (-1) unknown - not displayed,
+		 *   (-2) "not the same in all cells" - not displayed
+		 *   positive values - ok, displayed
+		 */
+		if (pd->cumulative.vpi >= 0)
+			col_append_fstr(pinfo->cinfo, COL_INFO, ", VPI:%.4d", pd->cumulative.vpi);
+		if (pd->cumulative.vci >= 0)
+			col_append_fstr(pinfo->cinfo, COL_INFO, ", VCI:%.5d", pd->cumulative.vci);
+		if (pd->cumulative.pti >= 0)
+			col_append_fstr(pinfo->cinfo, COL_INFO, ", PTI:%.1d", pd->cumulative.pti);
+		if (pd->cumulative.clp >= 0)
+			col_append_fstr(pinfo->cinfo, COL_INFO, ", CLP:%.1d", pd->cumulative.clp);
+	}
+	
+	if (padding_size != 0)
+	{
+		col_append_fstr(pinfo->cinfo, COL_INFO, ", %d padding"
+			,(int)padding_size);
+	}
 }
 
+		
+static
+void prepare_pseudo_header_atm(
+	union wtap_pseudo_header * const ph,
+	const pwatm_private_data_t * const pdata,
+	const unsigned aal)
+{
+	assert(NULL != pdata);
+	assert(NULL != ph);
+
+	memset(ph,0,sizeof(*ph)); /* it is OK to clear unknown values */
+	ph->atm.flags		= 0; /* status flags */
+	ph->atm.aal		= aal;
+	ph->atm.type		= TRAF_UNKNOWN;
+	ph->atm.subtype		= TRAF_ST_UNKNOWN;
+	ph->atm.vpi		= (pdata->vpi >= 0) ? pdata->vpi : 0 /*unknown*/;
+	ph->atm.vci		= (pdata->vci >= 0) ? pdata->vci : 0 /*unknown*/;
+	ph->atm.aal2_cid	= 0; /*not applicable*//* channel id */
+	ph->atm.channel		= 0; /*unknown*//* link: 0 for DTE->DCE, 1 for DCE->DTE */
+	ph->atm.cells		= 0; /*zero indicates that we do not have trailer info*/
+	/*user-to-user indicator & CPI*/
+	ph->atm.aal5t_u2u	= 0; /* all bits unknown except lsb of UU */	
+	if (pdata->aal5_sdu_frame_relay_cr_bit)
+	{ /* Let's give Frame Relay C/R bit to ATM dissector.*/
+		ph->atm.aal5t_u2u |= (1<<8); /*UU octet is at << 8 in aal5t_u2u*/
+	}
+	ph->atm.aal5t_len	= 0; /*unknown*//* length of the packet from trailer*/
+	ph->atm.aal5t_chksum	= 0; /*unknown*//* checksum for AAL5 packet from trailer */
+	return;
+}
 
-static void
-dissect_pw_atm_aal5_pdu_cw(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+
+static
+void dissect_payload_and_padding(
+	tvbuff_t * tvb
+	,packet_info * pinfo
+	,proto_tree * tree
+	,const gint payload_size
+	,const gint padding_size)
 {
-        (void)tvb;
-        (void)pinfo;
-        (void)tree;
+	int dissected;
+	tvbuff_t* tvb_2;
+	pwatm_private_data_t* pd;
+
+	assert(NULL != pinfo);
+	pd = pinfo->private_data;
+	assert(NULL != pd);
+
+	for(dissected = 0, pd->pw_cell_number = 0;
+		payload_size > dissected;
+		++(pd->pw_cell_number))
+	{
+		tvb_2 = tvb_new_subset(tvb,dissected,-1,-1);
+		dissected += call_dissector(dh_cell_header, tvb_2, pinfo, tree);
+			
+		tvb_2 = tvb_new_subset(tvb,dissected,-1,-1);
+		
+		/*dissect as oam for specific vci/pti, just like atm dissector does*/
+		if (pd->vci >= 0 && pd->pti >=0)
+		{
+			if (atm_is_oam_cell(pd->vci,pd->pti))
+			{
+				pd->cell_mode_oam = TRUE;
+			}
+		}
+		
+		if (pd->cell_mode_oam)
+		{
+			union wtap_pseudo_header* pseudo_header_save;
+			union wtap_pseudo_header ph;
+			tvbuff_t* tvb_3;
+			int bytes_to_dissect;
+			/* prepare buffer for old-style dissector */
+			/* oam cell is always 48 bytes, but payload_size maybe too small */
+			if ((payload_size - dissected) >= SIZEOF_ATM_CELL_PAYLOAD)
+				bytes_to_dissect = SIZEOF_ATM_CELL_PAYLOAD;
+			else
+				bytes_to_dissect = (payload_size - dissected);
+			tvb_3 = tvb_new_subset(tvb_2,0,bytes_to_dissect,-1);
+			/*aal5_sdu: disable filling columns after 1st (valid) oam cell*/
+			if (pd->mode == PWATM_MODE_AAL5_SDU && pd->pw_cell_number > 0)
+			{
+				pd->enable_fill_columns_by_atm_dissector = FALSE;
+			}
+			/* save & prepare new pseudo header for atm aal5 decoding */
+			pseudo_header_save = pinfo->pseudo_header;
+			pinfo->pseudo_header = &ph;
+			prepare_pseudo_header_atm(&ph,pd,AAL_OAMCELL);
+
+			call_dissector(dh_atm_oam_cell, tvb_3, pinfo, tree);
+			dissected += bytes_to_dissect;
+			/* restore pseudo header */
+			pinfo->pseudo_header = pseudo_header_save;
+		}
+		else
+		{
+			dissected += call_dissector(dh_cell, tvb_2, pinfo, tree);
+		}
+	}
+	
+	if (padding_size != 0)
+	{
+		tvbuff_t* tvb_2;
+		tvb_2 = tvb_new_subset(tvb
+				,(tvb_reported_length_remaining(tvb, 0) - padding_size)
+				,-1
+				,-1);
+		call_dissector(dh_padding, tvb_2, pinfo, tree);
+	}
+	return;
 }
 
 
-static void
-dissect_pw_atm_aal5_pdu_nocw(tvbuff_t *tvb, packet_info *pinfo, 
-                             proto_tree *tree)
+static
+gboolean too_small_packet_or_notpw(tvbuff_t * tvb
+	,packet_info * pinfo
+	,proto_tree * tree
+	,const int proto_handler
+	,const char * const proto_name_column)
 {
-        (void)tvb;
-        (void)pinfo;
-        (void)tree;
+	gint packet_size;
+	packet_size = tvb_reported_length_remaining(tvb, 0);
+	/*
+	 * FIXME
+	 * "4" below should be replaced by something like "min_packet_size_this_dissector"
+	 * Also call to dissect_try_cw_first_nibble() should be moved before this block
+	 */
+	if (packet_size < 4) /* 4 is smallest size which may be sensible (for PWACH dissector) */
+	{
+		if (tree)
+		{
+			proto_item  *item;
+			item = proto_tree_add_item(tree, proto_handler, tvb, 0, -1, FALSE);
+			expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR,
+				"PW packet size (%d) is too small to carry sensible information"
+				,(int)packet_size);
+		}
+		/* represent problems in the Packet List pane */
+		if (check_col(pinfo->cinfo, COL_PROTOCOL))
+		{
+			col_set_str(pinfo->cinfo, COL_PROTOCOL, proto_name_column);
+		}
+		if (check_col(pinfo->cinfo, COL_INFO))
+		{
+			col_set_str(pinfo->cinfo, COL_INFO,
+				"Malformed: PW packet is too small");
+		}
+		return TRUE;
+	}
+	if (dissect_try_cw_first_nibble(tvb, pinfo, tree))
+	{
+		return TRUE;
+	}
+	return FALSE;
 }
 
-static void
-dissect_pw_atm_aal5_sdu_cw(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+
+/*
+ * NOTE. RFC describes ATM-specific byte in a cumbersome way.
+ * It is a part of CW, but at the same time, it must be repeated
+ * with each cell, _except_ first.
+ *
+ * Alternatively, ATM-specific byte may be considered as part of
+ * PW payload (i.e., as part of pw atm cell header), so we can say that
+ * it is being repeated with each cell.
+ *
+ * This dissector is written according to the latter consideration.
+ */
+static
+void dissect_11_or_aal5_pdu(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
 {
-        (void)tvb;
-        (void)pinfo;
-        (void)tree;
+	const char *proto_name_column;
+	const char *proto_name_tree = NULL;
+	gint payload_size;
+	int cells;
+	pwatm_private_data_t pd = PWATM_PRIVATE_DATA_T_INITIALIZER;
+	void * pd_save = pinfo->private_data;
+	pinfo->private_data = &pd;
+
+	proto_name_column = &shortname_11_or_aal5_pdu[0];
+	if (too_small_packet_or_notpw(tvb,pinfo,tree,proto_11_or_aal5_pdu,proto_name_column))
+	{
+		return;
+	}
+	pd.packet_size = tvb_reported_length_remaining(tvb, 0);
+
+	/*
+	 * Guess encapsulation mode according to M & V bits from the 3rd byte of CW.
+	 * Also adjust protocol name strings.
+	 */
+	{
+		guint8 third_byte;
+		third_byte = tvb_get_guint8(tvb, 3);
+		if (0 == (third_byte & 0x80 /*generic_cw.m*/))
+		{ /*1:1 modes*/
+			if (0 != (third_byte & 0x40 /*generic_cw.v*/))
+			{
+				pd.mode = PWATM_MODE_11_VPC;
+				proto_name_column = &shortname_11_vpc[0];
+				proto_name_tree = &longname_pw_atm_11_vpc[0];
+			}
+			else
+			{
+				pd.mode = PWATM_MODE_11_VCC;
+				proto_name_column = &shortname_11_vcc[0];
+				proto_name_tree = &longname_pw_atm_11_vcc[0];
+			}
+		}
+		else
+		{
+			pd.mode = PWATM_MODE_AAL5_PDU;
+			proto_name_column = &shortname_aal5_pdu[0];
+			proto_name_tree = &longname_pw_atm_aal5_pdu[0];
+		}
+	}
+	
+	
+	/* check how "good" is this packet */
+	pd.props = PWC_PACKET_PROPERTIES_T_INITIALIZER;
+	if (0 != (tvb_get_guint8(tvb, 0) & 0xf0 /*bits03*/))
+	{
+		pd.props |= PWC_CW_BAD_BITS03;
+	}
+	if (0 != (tvb_get_guint8(tvb, 0) & 0x0f /*generic_cw.rsvd*/))
+	{
+		pd.props |= PWC_CW_BAD_RSV;
+	}
+	
+	/*
+	 * Do not dissect and validate atm-specific byte (3rd byte of CW).
+	 * It will be dissected/validated as pw cell header.
+	 */
+	
+	/*
+	 * Decide about payload length and padding.
+	 *
+	 * Is padding allowed?
+	 * 	eth header length  == 14
+	 * 	mpls label length  ==  4
+	 * 	cw length 	   ==  4
+	 * 	min payload length == 48
+	 * 	=> 14 + 4 + 4 + 48 == 70
+	 *        => 70 >= 64
+	 *	    => no padding allowed
+	 */
+	if (MODE_11(pd.mode))
+	{
+		gint bad_padding_size;
+		payload_size = pd.packet_size - (PWC_SIZEOF_CW-1);
+		cells = number_of_cells(pd.mode,pd.submode,payload_size,&bad_padding_size);
+		if (0 == cells || 0 != bad_padding_size)
+		{
+			pd.props |= PWC_PAY_SIZE_BAD;
+		}
+	}
+	else
+	{ /*aal5_pdu mode*/
+		gint bad_padding_size;
+		payload_size = pd.packet_size - PWC_SIZEOF_CW;
+		cells = number_of_cells(pd.mode,pd.submode,payload_size,&bad_padding_size);
+		/* at least 1 cell must be present in the packet in this mode*/
+		if (1 > cells || 0 != bad_padding_size)
+		{
+			pd.props |= PWC_PAY_SIZE_BAD;
+		}
+		cells = -1; /*this value not needed anymore, suppress pinting of it*/
+	}
+
+	if (PWATM_MODE_AAL5_PDU == pd.mode)
+	{
+		/* sub-dissectors _may_ overwrite columns in aal5_pdu mode */
+		if (check_col(pinfo->cinfo, COL_PROTOCOL))
+		{
+			col_set_str(pinfo->cinfo, COL_PROTOCOL, proto_name_column);
+		}
+		if (check_col(pinfo->cinfo, COL_INFO))
+		{
+			col_clear(pinfo->cinfo, COL_INFO);
+			col_append_pw_info(pinfo, payload_size, cells, 0);
+		}
+	}
+
+	if (tree)
+	{
+		proto_item* item;
+		item = proto_tree_add_item(tree, proto_11_or_aal5_pdu, tvb, 0, -1, FALSE);
+		/*overwrite heading line*/
+		proto_item_set_text(item, proto_name_tree, 0/*-warn gcc 3.4.4*/); 
+		pwc_item_append_text_n_items(item,cells,"good ATM cell");
+		{
+			proto_tree* tree;
+			tree = proto_item_add_subtree(item, ett_encaps);
+			{
+				proto_item* item;
+				item = proto_tree_add_boolean(tree
+					,VALUE_SELECTOR_VPC_VCC_PDU(pd.mode
+						,hf_pw_type_11_vpc
+						,hf_pw_type_11_vcc
+						,hf_pw_type_aal5_pdu)
+					,tvb, 0, 0, TRUE);
+				PROTO_ITEM_SET_GENERATED(item);
+				if (MODE_11(pd.mode))
+				{
+					item = proto_tree_add_int(tree, hf_11_ncells, tvb, 0, 0, cells);
+					PROTO_ITEM_SET_GENERATED(item);
+				}
+			}
+		}
+		if (pd.props & PWC_PAY_SIZE_BAD)
+		{
+			expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR
+				,"PW payload size (%d) must be <> 0 and multiple of %d"
+				,(int)payload_size,pw_cell_size(pd.mode,pd.submode));
+			if (payload_size != 0 && MODE_11(pd.mode))
+			{
+				expert_add_info_format(pinfo, item, PI_MALFORMED, PI_NOTE,
+					"PW ATM cell [%.3d] is broken",(int)cells);
+			}
+		}
+	}
+	
+	{
+		tvbuff_t* tvb_2;
+		tvb_2 = tvb_new_subset(tvb, 0, PWC_SIZEOF_CW, PWC_SIZEOF_CW);
+		call_dissector(dh_control_word, tvb_2, pinfo, tree);
+		
+		tvb_2 = tvb_new_subset(tvb, (PWC_SIZEOF_CW-1), -1, -1);
+		if (MODE_11(pd.mode))
+		{
+			dissect_payload_and_padding(tvb_2,pinfo,tree,payload_size,0);
+		}
+		else
+		{ /*aal5_pdu mode*/
+			if (payload_size != 0)
+			{
+				tvbuff_t* tvb_3;
+				union wtap_pseudo_header* pseudo_header_save;
+				union wtap_pseudo_header ph;
+				
+				tvb_3 = tvb_new_subset(tvb_2, 1, -1, -1);
+				/* prepare pseudo header for atm aal5 decoding */
+				pseudo_header_save = pinfo->pseudo_header;
+				pinfo->pseudo_header = &ph;
+				prepare_pseudo_header_atm(&ph,&pd,AAL_5);
+				call_dissector(dh_atm_untruncated, tvb_3, pinfo, tree);
+				/* restore pseudo header */
+				pinfo->pseudo_header = pseudo_header_save;
+			}
+		}
+	}
+	
+	if (MODE_11(pd.mode))
+	{
+		/* overwrite everything written by sub-dissectors in 1:1 modes*/
+		if (check_col(pinfo->cinfo, COL_PROTOCOL))
+		{
+			col_set_str(pinfo->cinfo, COL_PROTOCOL, proto_name_column);
+		}
+		if (check_col(pinfo->cinfo, COL_INFO))
+		{
+			col_clear(pinfo->cinfo, COL_INFO);
+			col_append_pw_info(pinfo, payload_size, cells, 0);
+		}
+	}
+	
+	pinfo->private_data = pd_save;
+	return;
 }
 
-static void
-dissect_pw_atm_aal5_sdu_nocw(tvbuff_t *tvb, packet_info *pinfo, 
-                             proto_tree *tree)
+
+static
+void dissect_aal5_sdu(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
 {
-        (void)tvb;
-        (void)pinfo;
-        (void)tree;
+	const char *proto_name_column;
+	gint payload_size;
+	gint padding_size;
+	int cells;
+	pwatm_private_data_t pd = PWATM_PRIVATE_DATA_T_INITIALIZER;
+	void * pd_save = pinfo->private_data;
+
+	pinfo->private_data = &pd;
+	pd.mode = PWATM_MODE_AAL5_SDU;
+
+	proto_name_column = &shortname_aal5_sdu[0];
+	if (too_small_packet_or_notpw(tvb,pinfo,tree,proto_aal5_sdu,proto_name_column))
+	{
+		return;
+	}
+	pd.packet_size = tvb_reported_length_remaining(tvb, 0);
+
+	/* check how "good" is this packet */
+	/* also decide payload length from packet size and CW */
+	if (0 != (tvb_get_guint8(tvb, 0) & 0xf0 /*bits03*/))
+	{
+		pd.props |= PWC_CW_BAD_BITS03;
+	}
+
+	pd.submode = PWATM_SUBMODE_DEFAULT;
+	if (0 != (tvb_get_guint8(tvb, 0) & 0x08 /*preferred_cw.T*/))
+	{
+		pd.submode = PWATM_SUBMODE_ADMIN_CELL;
+	}
+	
+	if (! pref_aal5_sdu_extend_cw_length_with_rsvd)
+	{
+		if (0 != (tvb_get_guint8(tvb, 1) & 0xc0 /*preferred_cw.rsvd*/))
+		{
+			pd.props |= PWC_CW_BAD_RSV;
+		}
+	}
+	{
+		/* RFC4717:
+		 * [ If the packet's length (defined as the length of the layer 2 payload
+		 * plus the length of the control word) is less than 64 bytes, the
+		 * length field MUST be set to the packet's length.  Otherwise, the
+		 * length field MUST be set to zero... Note that the length field
+		 * is not used in the N-to-one mode and MUST be set to 0. ]
+		 * 		
+		 * Also we allow some "extensions"conducted by pref_xxx.
+		 */
+		gint payload_size_from_packet;
+		int cw_len; /*length field from cw*/
+
+		payload_size_from_packet = pd.packet_size - PWC_SIZEOF_CW;
+		if (pref_aal5_sdu_extend_cw_length_with_rsvd)
+		{
+			cw_len = tvb_get_guint8(tvb, 1) & 0xff;
+		}
+		else
+		{
+			cw_len = tvb_get_guint8(tvb, 1) & 0x3f;
+		}
+		
+		/*
+		 * Initial assumptions: no padding,
+		 * payload size derived from psn packet size.
+		 */
+		payload_size = payload_size_from_packet;
+		padding_size = 0;
+		
+		if (0 == cw_len)
+		{
+			/*keep initial assumptions*/
+		}
+		else if (!pref_aal5_sdu_allow_cw_length_nonzero
+		         && PWATM_SUBMODE_ADMIN_CELL == pd.submode)
+		{
+			/*
+			 * The "allow CW.Length != 0" option affects
+			 * ATM admin cell submode only, because this submode
+			 * is equal to N:1 encapsulation.
+			 * CW.Length !=0 is always OK for normal (AAL5 payload) submode.
+			 */
+			pd.props |= PWC_CW_BAD_LEN_MUST_BE_0;
+		}
+		else
+		{
+			gint payload_size_from_cw;
+			payload_size_from_cw = cw_len - PWC_SIZEOF_CW;
+			if (payload_size_from_cw <= 0)
+			{
+				pd.props |= PWC_CW_BAD_PAYLEN_LE_0;
+			}
+			else if (payload_size_from_cw > payload_size_from_packet)
+			{
+				pd.props |= PWC_CW_BAD_PAYLEN_GT_PACKET;
+			}
+			else
+			{
+
+				payload_size = payload_size_from_cw;
+				padding_size = payload_size_from_packet - payload_size_from_cw; /* >=0 */
+				if (padding_size != 0)
+				{
+					/*
+					 * Padding is not allowed in ATM admin cell submode only,
+					 * because this submode is equal to N:1 encapsulation.
+					 * Padding is OK for normal (AAL5 payload) submode.
+					 */
+					if (PWATM_SUBMODE_ADMIN_CELL == pd.submode)
+					{
+						pd.props |= PWC_CW_BAD_PADDING_NE_0;
+						/*restore sizes*/
+						payload_size = payload_size_from_packet;
+						padding_size = 0;
+					}
+				}
+			}
+		}
+		
+		if (PWATM_SUBMODE_ADMIN_CELL == pd.submode)
+		{
+			gint bad_padding_size;
+			cells = number_of_cells(pd.mode,pd.submode,payload_size,&bad_padding_size);
+			/* only one atm admin cell is allowed in the packet in this mode*/
+			if (1 != cells || 0 != bad_padding_size)
+			{
+				pd.props |= PWC_PAY_SIZE_BAD;
+			}
+		}
+		else
+		{
+			cells = -1; /*unknown*/
+			/* Any size is allowed for AAL5 SDU payload */
+		}
+	}
+
+	/* fill columns in Packet List */
+	if (check_col(pinfo->cinfo, COL_PROTOCOL))
+	{
+		col_set_str(pinfo->cinfo, COL_PROTOCOL, proto_name_column);
+		if (PWATM_SUBMODE_ADMIN_CELL == pd.submode)
+		{
+			col_append_str(pinfo->cinfo, COL_PROTOCOL, ", OAM cell");
+		}
+	}
+	
+	if (check_col(pinfo->cinfo, COL_INFO))
+	{
+		col_clear(pinfo->cinfo, COL_INFO);
+		col_append_pw_info(pinfo, payload_size, cells, padding_size);
+	}
+
+	if (tree)
+	{
+		proto_item* item;
+		item = proto_tree_add_item(tree, proto_aal5_sdu, tvb, 0, -1, FALSE);
+		{
+			proto_tree* tree;
+			tree = proto_item_add_subtree(item, ett_encaps);
+			{
+				item = proto_tree_add_boolean(tree, hf_pw_type_aal5_sdu, tvb, 0, 0, TRUE);
+				PROTO_ITEM_SET_GENERATED(item);
+			}
+		}
+		if (pd.props & PWC_PAY_SIZE_BAD)
+		{
+			DISSECTOR_ASSERT(PWATM_SUBMODE_ADMIN_CELL == pd.submode);
+			expert_add_info_format(pinfo, item, PI_MALFORMED ,PI_ERROR
+				,"In ATM admin cell mode,"
+				" PW payload size (%d) must be == %d (exactly 1 admin cell)"
+				,(int)payload_size,(int)SIZEOF_N1_PW_CELL);
+		}
+	}
+	
+	{
+		tvbuff_t* tvb_2;
+		tvb_2 = tvb_new_subset(tvb, 0, PWC_SIZEOF_CW, PWC_SIZEOF_CW);
+		call_dissector(dh_control_word, tvb_2, pinfo, tree);
+		
+		tvb_2 = tvb_new_subset(tvb, PWC_SIZEOF_CW, -1, -1);
+		if (PWATM_SUBMODE_ADMIN_CELL == pd.submode)
+		{
+			dissect_payload_and_padding(tvb_2,pinfo,tree,payload_size,padding_size);
+		}
+		else /*AAL5 payload*/
+		{	
+			if (payload_size != 0)
+			{
+				tvbuff_t* tvb_3;
+				union wtap_pseudo_header* pseudo_header_save;
+				union wtap_pseudo_header ph;
+				
+				tvb_3 = tvb_new_subset(tvb_2, 0, payload_size, payload_size);
+				/* prepare pseudo header for atm aal5 decoding */
+				pseudo_header_save = pinfo->pseudo_header;
+				pinfo->pseudo_header = &ph;
+				prepare_pseudo_header_atm(&ph,&pd,AAL_5);
+				call_dissector(dh_atm_truncated, tvb_3, pinfo, tree); /* no PAD and trailer */
+				/* restore pseudo header */
+				pinfo->pseudo_header = pseudo_header_save;
+			}
+			if (padding_size != 0)
+			{
+				tvbuff_t* tvb_3;
+				tvb_3 = tvb_new_subset(tvb_2, payload_size, padding_size, -1);
+				call_dissector(dh_padding, tvb_3, pinfo, tree);
+			}
+		}
+	}
+
+	pinfo->private_data = pd_save;
+	return;
 }
-#endif
 
-void
-proto_register_pw_atm(void)
+
+static
+void dissect_n1_cw(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
 {
-        static hf_register_info hf[] = {
-                /* FF: general */
-                {
-                        &hf_pw_atm_n2o_cw,
-                        {
-                                "ATM PW, N-to-one Cell Mode (with CW)", 
-                                "pw_atm_n2o_cw", FT_BOOLEAN, 
-                                BASE_NONE, NULL, 0x0, NULL, HFILL
-                        }
-                },
-                {
-                        &hf_pw_atm_n2o_nocw,
-                        {
-                                "ATM PW, N-to-one Cell Mode (no CW)", 
-                                "pw_atm_n2o_nocw", FT_BOOLEAN, 
-                                BASE_NONE, NULL, 0x0, NULL, HFILL
-                        }
-                },
-#if 0
-                {
-                        &hf_pw_atm_o2o_cw,
-                        {
-                                "ATM PW, One-to-one Cell Mode (with CW)", 
-                                "pw_atm_o2o_cw", FT_BOOLEAN, 
-                                0, NULL, 0x0, NULL, HFILL
-                        }
-                },
-                {
-                        &hf_pw_atm_o2o_nocw,
-                        {
-                                "ATM PW, One-to-one Cell Mode (no CW)", 
-                                "pw_atm_o2o_nocw", FT_BOOLEAN, 
-                                0, NULL, 0x0, NULL, HFILL
-                        }
-                },
-                {
-                        &hf_pw_atm_aal5_pdu_cw,
-                        {
-                                "ATM PW, AAL5 PDU Frame Mode (with CW)", 
-                                "pw_atm_aal5_pdu_cw", FT_BOOLEAN, 
-                                0, NULL, 0x0, NULL, HFILL
-                        }
-                },
-                {
-                        &hf_pw_atm_aal5_pdu_nocw,
-                        {
-                                "ATM PW, AAL5 PDU Frame Mode (no CW)", 
-                                "pw_atm_aal5_pdu_nocw", FT_BOOLEAN, 
-                                0, NULL, 0x0, NULL, HFILL
-                        }
-                },
-                {
-                        &hf_pw_atm_aal5_sdu_cw,
-                        {
-                                "ATM PW, AAL5 SDU Frame Mode (with CW)", 
-                                "pw_atm_aal5_sdu_cw", FT_BOOLEAN, 
-                                0, NULL, 0x0, NULL, HFILL
-                        }
-                },
-                {
-                        &hf_pw_atm_aal5_sdu_nocw,
-                        {
-                                "ATM PW, AAL5 SDU Frame Mode (no CW)", 
-                                "pw_atm_aal5_sdu_nocw", FT_BOOLEAN, 
-                                0, NULL, 0x0, NULL, HFILL
-                        }
-                },
-                /* FF: ATM One-to-one Cell Mode Control Word fields */
-                {
-                        &hf_pw_atm_o2o_cw_sequence_number,
-                        {
-                                "ATM One-to-one Cell Mode sequence number", 
-                                "pw_atm_o2o_cw_sequence_number", FT_UINT16, 
-                                BASE_DEC, NULL, 0x0, NULL, HFILL
-                        }
-                },
-                {
-                        &hf_pw_atm_o2o_cw_flags,
-                        {
-                                "ATM One-to-one Cell Mode flags",
-                                "pw_atm_o2o_cw_flags", FT_UINT8, 
-                                BASE_HEX, NULL, 0x0, NULL, HFILL 
-                        }
-
-                },
-                {
-                        &hf_pw_atm_o2o_cw_flags_m,
-                        {
-                                "M (transport mode) bit",
-                                "pw_atm_o2o_cw_flags_m", FT_BOOLEAN, 
-                                8, TFS(&flags_set_truth), PW_ATM_O2O_CW_M,
-                                NULL, HFILL 
-                        }
-                },
-                {
-                        &hf_pw_atm_o2o_cw_flags_v,
-                        {
-                                "V (VCI present) bit",
-                                "pw_atm_o2o_cw_flags_v", FT_BOOLEAN, 
-                                8, TFS(&flags_set_truth), PW_ATM_O2O_CW_V,
-                                NULL, HFILL 
-                        }
-                },
-                {
-                        &hf_pw_atm_o2o_cw_flags_res,
-                        {
-                                "Reserved bits",
-                                "pw_atm_o2o_cw_flags_res", FT_BOOLEAN, 
-                                8, TFS(&flags_set_truth), PW_ATM_O2O_CW_RES,
-                                NULL, HFILL 
-                        }
-                },
-                {
-                        &hf_pw_atm_o2o_cw_flags_pti,
-                        {
-                                "PTI bits",
-                                "pw_atm_o2o_cw_flags_pti", FT_BOOLEAN, 
-                                8, TFS(&flags_set_truth), PW_ATM_O2O_CW_PTI,
-                                NULL, HFILL 
-                        }
-                },
-                {
-                        &hf_pw_atm_o2o_cw_flags_c,
-                        {
-                                "C (CLP) bit",
-                                "pw_atm_o2o_cw_flags_c", FT_BOOLEAN, 
-                                8, TFS(&flags_set_truth), PW_ATM_O2O_CW_C,
-                                NULL, HFILL 
-                        }
-                },
-                /* FF: AAL5 PDU Frame Mode Control Word fields */
-                {
-                        &hf_pw_atm_aal5_pdu_cw_sequence_number,
-                        {
-                                "AAL5 PDU Frame Mode sequence number", 
-                                "pw_atm_aal5_pdu_cw_sequence_number", 
-                                FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL
-                        }
-                },
-                /* FF: AAL5 SDU Frame Mode Control Word fields */
-                {
-                        &hf_pw_atm_aal5_sdu_cw_sequence_number,
-                        {
-                                "AAL5 SDU Frame Mode sequence number", 
-                                "pw_atm_aal5_sdu_cw_sequence_number", 
-                                FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL
-                        }
-                },
-#endif
-                /* FF: ATM N-to-one Cell Mode Control Word fields */
-                {
-                        &hf_pw_atm_n2o_cw_flags,
-                        {
-                                "ATM N-to-one Cell Mode flags",
-                                "pw_atm_n2o_cw_flags", FT_UINT8, 
-                                BASE_HEX, NULL, 0x0, NULL, HFILL 
-                        }
-
-                },
-                {
-                        &hf_pw_atm_n2o_cw_length,
-                        {
-                                "ATM N-to-one Cell Mode flags",
-                                "pw_atm_n2o_cw_length", FT_UINT8, 
-                                BASE_HEX, NULL, 0x0, NULL, HFILL 
-                        }
-
-                },
-                {
-                        &hf_pw_atm_n2o_cw_sequence_number,
-                        {
-                                "ATM N-to-one Cell Mode sequence number", 
-                                "pw_atm_n2o_cw_sequence_number", FT_UINT16, 
-                                BASE_DEC, NULL, 0x0, NULL, HFILL
-                        }
-                },
-        };
-
-        static gint *ett[] = {
-                &ett_pw_atm
-        };
-
-        proto_pw_atm_n2o_cw = 
-          proto_register_protocol("ATM PW, N-to-one Cell Mode Control Word",
-                                  "ATM PW, N-to-one Cell Mode (with CW)",
-                                  "pw_atm_n2o_cw");
-        proto_pw_atm_n2o_nocw = 
-          proto_register_protocol("ATM PW, N-to-one Cell Mode (no CW)",
-                                  "ATM PW, N-to-one Cell Mode (no CW)",
-                                  "pw_atm_n2o_nocw");
-#if 0
-        proto_pw_atm_o2o_cw = 
-          proto_register_protocol("ATM PW, One-to-one Cell Mode Control Word",
-                                  "ATM PW, One-to-one Cell Mode (with CW)",
-                                  "pw_atm_o2o_cw");
-        proto_pw_atm_o2o_nocw = 
-          proto_register_protocol("ATM PW, One-to-one Cell Mode (no CW)",
-                                  "ATM PW, One-to-one Cell Mode (no CW)",
-                                  "pw_atm_o2o_nocw");
-        proto_pw_atm_aal5_pdu_cw = 
-          proto_register_protocol("ATM PW, AAL5 PDU Frame Mode Control Word",
-                                  "ATM PW, AAL5 PDU Frame Mode (with CW)",
-                                  "pw_atm_aal5_pdu_cw");
-        proto_pw_atm_aal5_pdu_nocw = 
-          proto_register_protocol("ATM PW, AAL5 PDU Frame Mode (no CW)",
-                                  "ATM PW, AAL5 PDU Frame Mode (no CW)",
-                                  "pw_atm_aal5_pdu_nocw");
-        proto_pw_atm_aal5_sdu_cw = 
-          proto_register_protocol("ATM PW, AAL5 SDU Frame Mode Control Word",
-                                  "ATM PW, AAL5 SDU Frame Mode (with CW)",
-                                  "pw_atm_aal5_sdu_cw");
-        proto_pw_atm_aal5_sdu_nocw = 
-          proto_register_protocol("ATM PW, AAL5 SDU Frame Mode (no CW)",
-                                  "ATM PW, AAL5 SDU Frame Mode (no CW)",
-                                  "pw_atm_aal5_sdu_nocw");
-#endif
+	const char *proto_name_column;
+	gint payload_size;
+	gint padding_size;
+	int cells;
+	pwatm_private_data_t pd = PWATM_PRIVATE_DATA_T_INITIALIZER;
+	void * pd_save = pinfo->private_data;
 
-        proto_register_field_array(proto_pw_atm_n2o_cw, hf, array_length(hf));
-        proto_register_subtree_array(ett, array_length(ett));   
-
-        register_dissector("pw_atm_n2o_cw", 
-                           dissect_pw_atm_n2o_cw, 
-                           proto_pw_atm_n2o_cw);
-        register_dissector("pw_atm_n2o_nocw", 
-                           dissect_pw_atm_n2o_nocw, 
-                           proto_pw_atm_n2o_nocw);
-#if 0
-        register_dissector("pw_atm_o2o_cw", 
-                           dissect_pw_atm_o2o_cw, 
-                           proto_pw_atm_o2o_cw);
-        register_dissector("pw_atm_o2o_nocw", 
-                           dissect_pw_atm_o2o_nocw, 
-                           proto_pw_atm_o2o_nocw);
-        register_dissector("pw_atm_aal5_pdu_cw", 
-                           dissect_pw_atm_aal5_pdu_cw, 
-                           proto_pw_atm_aal5_pdu_cw);
-        register_dissector("pw_atm_aal5_pdu_nocw", 
-                           dissect_pw_atm_aal5_pdu_nocw, 
-                           proto_pw_atm_aal5_pdu_nocw);
-        register_dissector("pw_atm_aal5_sdu_cw", 
-                           dissect_pw_atm_aal5_sdu_cw, 
-                           proto_pw_atm_aal5_sdu_cw);
-        register_dissector("pw_atm_aal5_sdu_nocw", 
-                           dissect_pw_atm_aal5_sdu_nocw, 
-                           proto_pw_atm_aal5_sdu_nocw);
-#endif
+	pinfo->private_data = &pd;
+	pd.mode = PWATM_MODE_N1_CW;
+
+	proto_name_column = &shortname_n1_cw[0];
+	if (too_small_packet_or_notpw(tvb,pinfo,tree,proto_n1_cw,proto_name_column))
+	{
+		return;
+	}
+	pd.packet_size = tvb_reported_length_remaining(tvb, 0);
+
+	/* check how "good" is this packet */
+	/* also decide payload length from packet size and CW */
+	pd.props = PWC_PACKET_PROPERTIES_T_INITIALIZER;
+	if (0 != (tvb_get_guint8(tvb, 0) & 0xf0 /*bits03*/))
+	{
+		pd.props |= PWC_CW_BAD_BITS03;
+	}
+	if (0 != (tvb_get_guint8(tvb, 0) & 0x0f /*preferred_cw.flags*/))
+	{
+		pd.props |= PWC_CW_BAD_FLAGS;
+	}
+	if (! pref_n1_cw_extend_cw_length_with_rsvd)
+	{
+		if (0 != (tvb_get_guint8(tvb, 1) & 0xc0 /*preferred_cw.rsvd*/))
+		{
+			pd.props |= PWC_CW_BAD_RSV;
+		}
+	}
+	{
+		/* RFC4717:
+		 * [ If the packet's length (defined as the length of the layer 2 payload
+		 * plus the length of the control word) is less than 64 bytes, the
+		 * length field MUST be set to the packet's length.  Otherwise, the
+		 * length field MUST be set to zero... Note that the length field
+		 * is not used in the N-to-one mode and MUST be set to 0. ]
+		 * 		
+		 * Also we allow some "extensions"conducted by pref_xxx.
+		 */
+		gint payload_size_from_packet;
+		int cw_len; /*length field from cw*/
+
+		payload_size_from_packet = pd.packet_size - PWC_SIZEOF_CW;
+		if (pref_n1_cw_extend_cw_length_with_rsvd)
+		{
+			cw_len = tvb_get_guint8(tvb, 1) & 0xff;
+		}
+		else
+		{
+			cw_len = tvb_get_guint8(tvb, 1) & 0x3f;
+		}
+		
+		/*
+		 * Initial assumptions: no padding,
+		 * payload size derived from psn packet size.
+		 */
+		payload_size = payload_size_from_packet;
+		padding_size = 0;
+		
+		if (0 == cw_len)
+		{
+			/*keep initial assumptions*/
+		}
+		else if (!pref_n1_cw_allow_cw_length_nonzero)
+		{
+			pd.props |= PWC_CW_BAD_LEN_MUST_BE_0;
+		}
+		else
+		{
+			gint payload_size_from_cw;
+			payload_size_from_cw = cw_len - PWC_SIZEOF_CW;
+			if (payload_size_from_cw <= 0)
+			{
+				pd.props |= PWC_CW_BAD_PAYLEN_LE_0;
+			}
+			else if (payload_size_from_cw > payload_size_from_packet)
+			{
+				pd.props |= PWC_CW_BAD_PAYLEN_GT_PACKET;
+			}
+			else
+			{
+
+				payload_size = payload_size_from_cw;
+				padding_size = payload_size_from_packet - payload_size_from_cw; /* >=0 */
+				if (padding_size != 0)
+				{
+					pd.props |= PWC_CW_BAD_PADDING_NE_0;
+					/*restore sizes*/
+					payload_size = payload_size_from_packet;
+					padding_size = 0;
+				}
+			}
+		}
+		{
+			gint bad_padding_size;
+			cells = number_of_cells(pd.mode,pd.submode,payload_size,&bad_padding_size);
+			if (0 == cells || 0 != bad_padding_size)
+			{
+				pd.props |= PWC_PAY_SIZE_BAD;
+			}
+		}
+	}
+
+	if (tree)
+	{
+		proto_item* item;
+		item = proto_tree_add_item(tree, proto_n1_cw, tvb, 0, -1, FALSE);
+		pwc_item_append_text_n_items(item,cells,"good ATM cell");
+		{
+			proto_tree* tree;
+			tree = proto_item_add_subtree(item, ett_encaps);
+			{
+				proto_item* item;
+				item = proto_tree_add_boolean(tree, hf_pw_type_n1_cw, tvb, 0, 0, TRUE);
+				PROTO_ITEM_SET_GENERATED(item);
+				item = proto_tree_add_int(tree, hf_n1_cw_ncells, tvb, 0, 0, cells);
+				PROTO_ITEM_SET_GENERATED(item);
+			}
+		}
+		if (pd.props & PWC_PAY_SIZE_BAD)
+		{
+			if (payload_size != 0)
+			{
+				expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR,
+					"PW ATM cell [%.3d] is broken",(int)cells);
+			}
+			expert_add_info_format(pinfo, item, PI_MALFORMED
+				, (payload_size == 0) ? PI_ERROR : PI_NOTE
+				,"PW payload size (%d) must be <>0 and multiple of %d"
+				,(int)payload_size,(int)SIZEOF_N1_PW_CELL);
+		}
+	}
+	
+	{
+		tvbuff_t* tvb_2;
+		tvb_2 = tvb_new_subset(tvb, 0, PWC_SIZEOF_CW, PWC_SIZEOF_CW);
+		call_dissector(dh_control_word, tvb_2, pinfo, tree);
+		
+		tvb_2 = tvb_new_subset(tvb, PWC_SIZEOF_CW, -1, -1);
+		dissect_payload_and_padding(tvb_2,pinfo,tree,payload_size,padding_size);
+	}
+
+	/* fill columns in Packet List */
+	/* overwrite everything written by sub-dissectors */
+	if (check_col(pinfo->cinfo, COL_PROTOCOL))
+	{
+		col_set_str(pinfo->cinfo, COL_PROTOCOL, proto_name_column);
+	}
+
+	if (check_col(pinfo->cinfo, COL_INFO))
+	{
+		col_clear(pinfo->cinfo, COL_INFO);
+		col_append_pw_info(pinfo, payload_size, cells, padding_size);
+	}
+	
+	pinfo->private_data = pd_save;
+	return;
 }
 
-void
-proto_reg_handoff_pw_atm(void)
+
+static
+void dissect_n1_nocw(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
 {
-        dissector_handle_t pw_atm_n2o_cw_h; 
-        dissector_handle_t pw_atm_n2o_nocw_h;
-#if 0
-        dissector_handle_t pw_atm_o2o_cw_h;
-        dissector_handle_t pw_atm_o2o_nocw_h;
-        dissector_handle_t pw_atm_aal5_pdu_cw_h;
-        dissector_handle_t pw_atm_aal5_pdu_nocw_h;
-        dissector_handle_t pw_atm_aal5_sdu_cw_h;
-        dissector_handle_t pw_atm_aal5_sdu_nocw_h;
-#endif
+	const char *proto_name_column = &shortname_n1_nocw[0];
+	gint payload_size;
+	int cells;
+	pwatm_private_data_t pd = PWATM_PRIVATE_DATA_T_INITIALIZER;
+	void * pd_save = pinfo->private_data;
 
-        pw_atm_n2o_cw_h = find_dissector("pw_atm_n2o_cw");
-        dissector_add("mpls.label", LABEL_INVALID, pw_atm_n2o_cw_h);
+	pinfo->private_data = &pd;
+	pd.mode = PWATM_MODE_N1_NOCW;
+	pd.packet_size = tvb_reported_length_remaining(tvb, 0);
 
-        pw_atm_n2o_nocw_h = find_dissector("pw_atm_n2o_nocw");
-        dissector_add("mpls.label", LABEL_INVALID, pw_atm_n2o_nocw_h);
-#if 0
-        pw_atm_o2o_cw_h = find_dissector("pw_atm_o2o_cw");
-        dissector_add("mpls.label", LABEL_INVALID, pw_atm_o2o_cw_h);
+	/* check how "good" is this packet */
+	/* also decide payload length from packet size */
+	pd.props = PWC_PACKET_PROPERTIES_T_INITIALIZER;
+	payload_size = pd.packet_size;
+	{
+		gint bad_padding_size;
+		cells = number_of_cells(pd.mode,pd.submode,pd.packet_size,&bad_padding_size);
+		if (cells == 0 || bad_padding_size != 0)
+		{
+			pd.props |= PWC_PAY_SIZE_BAD;
+		}
+	}
 
-        pw_atm_o2o_nocw_h = find_dissector("pw_atm_o2o_nocw");
-        dissector_add("mpls.label", LABEL_INVALID, pw_atm_o2o_nocw_h);
+	if (tree)
+	{
+		proto_item* item;
+		item = proto_tree_add_item(tree, proto_n1_nocw, tvb, 0, -1, FALSE);
+		pwc_item_append_text_n_items(item,cells,"ATM cell");
+		{
+			proto_tree* tree;
+			tree = proto_item_add_subtree(item, ett_encaps);
+			{
+				proto_item* item;
+				item = proto_tree_add_boolean(tree, hf_pw_type_n1_nocw, tvb, 0, 0, TRUE);
+				PROTO_ITEM_SET_GENERATED(item);
+				item = proto_tree_add_int(tree, hf_n1_nocw_ncells, tvb, 0, 0, cells);
+				PROTO_ITEM_SET_GENERATED(item);
+			}
+		}
+		if (pd.props & PWC_PAY_SIZE_BAD)
+		{
+			if (payload_size != 0)
+			{
+				expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR,
+					"Last PW ATM cell [%.3d] is broken",(int)cells);
+			}
+			expert_add_info_format(pinfo, item, PI_MALFORMED
+				, (payload_size == 0) ? PI_ERROR : PI_NOTE
+				,"PW payload size (%d) must be <>0 and multiple of %d"
+				,(int)payload_size,(int)SIZEOF_N1_PW_CELL);
+		}
+	}
+	
+	dissect_payload_and_padding(tvb,pinfo,tree,payload_size,0);
+	
+	/* fill columns in Packet List */
+	/* overwrite everything written by sub-dissectors */
+	if (check_col(pinfo->cinfo, COL_PROTOCOL))
+	{
+		col_set_str(pinfo->cinfo, COL_PROTOCOL, proto_name_column);
+	}
 
-        pw_atm_aal5_pdu_cw_h = find_dissector("pw_atm_aal5_pdu_cw");
-        dissector_add("mpls.label", LABEL_INVALID, pw_atm_aal5_pdu_cw_h);
+	if (check_col(pinfo->cinfo, COL_INFO))
+	{
+		col_clear(pinfo->cinfo, COL_INFO);
+		col_append_pw_info(pinfo, payload_size, cells, 0);
+	}
 
-        pw_atm_aal5_pdu_nocw_h = find_dissector("pw_atm_aal5_pdu_nocw");
-        dissector_add("mpls.label", LABEL_INVALID, pw_atm_aal5_pdu_nocw_h);
+	pinfo->private_data = pd_save;
+	return;
+}
 
-        pw_atm_aal5_sdu_cw_h = find_dissector("pw_atm_aal5_sdu_cw");
-        dissector_add("mpls.label", LABEL_INVALID, pw_atm_aal5_sdu_cw_h);
 
-        pw_atm_aal5_sdu_nocw_h = find_dissector("pw_atm_aal5_sdu_nocw");
-        dissector_add("mpls.label", LABEL_INVALID, pw_atm_aal5_sdu_nocw_h);
-#endif
+static
+void proto_item_append_text_cwb3_fields(proto_item * item, const pwatm_private_data_t * const pd)
+{
+	if (NULL == item) return;
+	assert(NULL != pd);
+	if (pd->cwb3.m   >= 0)
+		proto_item_append_text(item, "M:%.1u  "  , (unsigned)(pd->cwb3.m));
+	if (pd->cwb3.v   >= 0)
+		proto_item_append_text(item, "V:%.1u  "  , (unsigned)(pd->cwb3.v));
+	if (pd->cwb3.rsv >= 0)
+		proto_item_append_text(item, "RSV:%.1u  ", (unsigned)(pd->cwb3.rsv));
+	if (pd->cwb3.u >= 0)
+		proto_item_append_text(item, "U:%.1u  "  , (unsigned)(pd->cwb3.u));
+	if (pd->cwb3.e >= 0)
+		proto_item_append_text(item, "EFCI:%.1u  ",(unsigned)(pd->cwb3.e));
+	if (pd->cwb3.clp >= 0)
+		proto_item_append_text(item, "CLP:%.1u  ", (unsigned)(pd->cwb3.clp));
+	return;
+}
+		
+
+static
+void dissect_control_word(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
+{
+	pwatm_private_data_t* pd;
+	pd = pinfo->private_data;
+	assert(pd != NULL);
+
+	/*
+	 * NB: do not touch columns -- keep info from previous dissector
+	 */
+
+	{
+		gint size;
+		size = tvb_reported_length_remaining(tvb, 0);
+		if (size < PWC_SIZEOF_CW)
+		{
+			if (tree)
+			{
+				proto_item  *item;
+				item = proto_tree_add_item(tree, proto_control_word, tvb, 0, -1, FALSE);
+				expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR,
+					"Packet (size: %d) is too small to carry MPLS PW Control Word"
+					,(int)size);
+			}
+			return;
+		}
+	}
+
+	if (tree)
+	{
+		proto_item* item_top;
+		item_top = proto_tree_add_item(tree, proto_control_word, tvb, 0, -1, FALSE);
+		pwc_item_append_cw(item_top,tvb_get_ntohl(tvb, 0),FALSE);
+		
+		{
+			proto_tree* tree;
+			tree = proto_item_add_subtree(item_top, ett_cw);
+			{
+				proto_item* item;
+				/* bits 0..3 */
+				item = proto_tree_add_item(tree, hf_cw_bits03, tvb, 0, 1, FALSE);
+				if (pd->props & PWC_CW_BAD_BITS03)
+				{
+					/* add item to tree (and show it) only if its value is wrong*/
+					expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR
+						,"Bits 0..3 of Control Word must be 0");
+				}
+				else
+				{
+			                PROTO_ITEM_SET_HIDDEN(item); /* show only in error cases */
+		                }
+		
+				/* flags */
+				if (MODE_N1(pd->mode))
+				{
+					item = proto_tree_add_item(tree, hf_pref_cw_flags, tvb, 0, 1, FALSE);
+					if (pd->props & PWC_CW_BAD_FLAGS)
+					{
+						expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR
+							,"Flags must be 0 for PW ATM N:1 encapsulation");
+					}
+				}
+				if (pd->mode == PWATM_MODE_AAL5_SDU)
+				{
+					item = proto_tree_add_item(tree, hf_pref_cw_a5s_t, tvb, 0, 1, FALSE);
+					item = proto_tree_add_item(tree, hf_pref_cw_a5s_e, tvb, 0, 1, FALSE);
+					item = proto_tree_add_item(tree, hf_pref_cw_a5s_c, tvb, 0, 1, FALSE);
+					item = proto_tree_add_item(tree, hf_pref_cw_a5s_u, tvb, 0, 1, FALSE);
+					/*
+					 * rfc4717: [When FRF.8.1 Frame Relay/ATM PVC Service Interworking [RFC3916]
+					 * traffic is being transported, the CPCS-UU Least Significant Bit
+					 * (LSB) of the AAL5 CPCS-PDU may contain the Frame Relay C/R bit.
+					 * The ingress router, PE1, SHOULD copy this bit to the U bit of the
+					 * control word.  The egress router, PE2, SHOULD copy the U bit to
+					 * the CPCS-UU Least Significant Bit (LSB) of the AAL5 CPCS PDU.]
+					 *
+					 * Let's remember this bit (and then transfer it to ATM dissector).
+					 */
+					pd->aal5_sdu_frame_relay_cr_bit =
+						(0 == (tvb_get_guint8(tvb, 0) & 0x01 /*preferred_cw.U*/))
+						? FALSE : TRUE;
+				}
+				
+				/* reserved bits */
+				if (MODE_11_OR_AAL5_PDU(pd->mode)
+				|| (MODE_N1(pd->mode) && !pref_n1_cw_extend_cw_length_with_rsvd)
+					/* for N:1 add RSV only if it is NOT used in length */
+				|| ((pd->mode == PWATM_MODE_AAL5_SDU) && !pref_aal5_sdu_extend_cw_length_with_rsvd)
+					/* for AAl5 SDU add RSV only if it is NOT used in length */)
+				{
+					if (MODE_11_OR_AAL5_PDU(pd->mode))
+					{
+						item = proto_tree_add_item(tree
+							,hf_generic_cw_rsv, tvb, 0, 1, FALSE);
+					}
+					else
+					{ /*preferred cw*/
+						item = proto_tree_add_item(tree
+							,hf_pref_cw_rsv, tvb, 1, 1, FALSE);
+					}
+
+					if (pd->props & PWC_CW_BAD_RSV)
+					{
+						expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR
+							,"Reserved bits in Control Word must be 0");
+					}
+					else
+					{
+				                PROTO_ITEM_SET_HIDDEN(item); /*...and show only in error cases */
+			                }
+				}
+				
+				/* length */
+				if (MODE_N1(pd->mode)
+				|| (PWATM_MODE_AAL5_SDU == pd->mode))
+				{
+					{
+						int hf_len = hf_pref_cw_len;
+						if (MODE_N1(pd->mode))
+						{
+							if (pref_n1_cw_extend_cw_length_with_rsvd)
+								hf_len = hf_pref_cw_rsvlen;
+						}
+						else /*PW_MODE_AAL5_SDU*/
+						{
+							if (pref_aal5_sdu_extend_cw_length_with_rsvd)
+								hf_len = hf_pref_cw_rsvlen;
+						}
+						item = proto_tree_add_item(tree, hf_len, tvb, 1, 1, FALSE);
+					}
+					if (pd->props & PWC_CW_BAD_LEN_MUST_BE_0)
+					{
+						expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR
+							,"Bad Length: must be 0 for this encapsulation");
+					}
+					if (pd->props & PWC_CW_BAD_PAYLEN_LE_0)
+					{
+						expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR
+							,"Bad Length: too small, must be >= %d"
+							,(int)(PWC_SIZEOF_CW+SIZEOF_N1_PW_CELL));
+					}
+					if (pd->props & PWC_CW_BAD_PAYLEN_GT_PACKET)
+					{
+						expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR
+							,"Bad Length: must be <= than PSN packet size (%d)"
+							,(int)pd->packet_size);
+					}
+					if (pd->props & PWC_CW_BAD_PADDING_NE_0)
+					{
+						expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR
+							,"Bad Length: must be == PSN packet size (%d), no padding allowed"
+							,(int)pd->packet_size);
+					}
+				}
+				
+				/* sequence number */
+				(void)proto_tree_add_item(tree, hf_cw_seq, tvb
+					,MODE_11_OR_AAL5_PDU(pd->mode) ? 1 : 2, 2, FALSE);
+				
+				/* atm-specific byte */
+				if (MODE_11(pd->mode))
+				{
+					(void) proto_tree_add_item(tree, hf_gen_cw_atmbyte, tvb, 3, 1, FALSE);
+					/*
+					 * no need to highlight item in the tree, therefore
+					 * expert_add_info_format() is not used here.
+					 */
+					item = proto_tree_add_text(tree,tvb,3,1
+						,"ATM-specific byte of CW is fully dissected below as %s%s"
+						,(PWATM_MODE_11_VPC == pd->mode) ? "a part of "	: ""
+						,"PW ATM Cell Header [000]");
+					PROTO_ITEM_SET_GENERATED(item);
+					/*
+					 * Note: if atm-specific byte contains something wrong
+					 * (e.g. non-zero RSV or inadequate V), CW is not
+					 * marked as "bad".
+					 */
+				}
+				
+				/*3rd byte of CW*/
+				if (PWATM_MODE_AAL5_PDU == pd->mode)
+				{
+					tvbuff_t* tvb_2;
+					tvb_2 = tvb_new_subset(tvb, (PWC_SIZEOF_CW-1), -1, -1);
+					call_dissector(dh_cell_header, tvb_2, pinfo, tree);
+					proto_item_append_text(item_top,", ");
+					proto_item_append_text_cwb3_fields(item_top,pd);
+				}
+			}
+		}
+	}
+	return;
+}
+
+
+/*
+ * This function is also used to dissect 3rd byte of CW in AAL5 PDU mode.
+ */
+static
+int dissect_cell_header(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
+{
+	pwatm_private_data_t * pd;
+	gboolean is_enough_data;
+	int dissect_size;
+	
+	pd = pinfo->private_data;
+	assert (NULL != pd);
+	pd->vpi = pd->vci = pd->pti = -1;
+	pd->cwb3.clp = pd->cwb3.m = pd->cwb3.v = pd->cwb3.rsv = pd->cwb3.u = pd->cwb3.e = -1;
+		
+	if (PWATM_MODE_AAL5_PDU == pd->mode)
+	{
+		if (tvb_reported_length_remaining(tvb, 0) < 1)
+		{
+			is_enough_data = FALSE;
+			dissect_size = 0;
+		}
+		else
+		{
+			is_enough_data = TRUE;
+			dissect_size = 1;
+		}
+	}
+	else
+	{
+		gint size;
+		size = tvb_reported_length_remaining(tvb, 0);
+
+		if (size < pw_cell_header_size(pd->mode,pd->submode))
+		{
+			is_enough_data = FALSE;
+			dissect_size = size;
+		}
+		else
+		{
+			is_enough_data = TRUE;
+			dissect_size = pw_cell_header_size(pd->mode,pd->submode);
+		}
+	}
+
+	/*
+	 * NB: do not touch columns -- keep info from previous dissector
+	 */
+	
+	/* Collect info for upper-level dissectors regardless of
+	 * the presence of the tree
+	 */
+	if (is_enough_data)
+	{
+		guint8 tmp8;
+		switch (pd->mode)
+		{
+		case PWATM_MODE_AAL5_SDU:
+			DISSECTOR_ASSERT(pd->submode == PWATM_SUBMODE_ADMIN_CELL);
+			/*fallthrough for ATM admin cell submode only*/
+		case PWATM_MODE_N1_CW:
+		case PWATM_MODE_N1_NOCW:
+			pd->vpi		= (tvb_get_ntohs (tvb, 0) >> 4);
+			pd->vci		= (tvb_get_ntoh24(tvb, 1) >> 4) & 0xffff;
+			tmp8 		= (tvb_get_guint8(tvb, 3));
+			pd->pti		= (tmp8 >> 1) & 0x07;
+			pd->cwb3.clp 	= (tmp8 >> 0) & 0x01;
+			UPDATE_CUMULATIVE_VALUE(pd->cumulative.vpi,pd->vpi);
+			UPDATE_CUMULATIVE_VALUE(pd->cumulative.vci,pd->vci);
+			UPDATE_CUMULATIVE_VALUE(pd->cumulative.pti,pd->pti);
+			UPDATE_CUMULATIVE_VALUE(pd->cumulative.clp,pd->cwb3.clp);
+			/*
+			 * OAM cell mode is always used for aal5_sdu/admin_cell mode,
+			 * even if pti indicates user cell.
+			 */
+			pd->cell_mode_oam =
+				(pd->mode == PWATM_MODE_AAL5_SDU && pd->submode == PWATM_SUBMODE_ADMIN_CELL)
+				|| PTI_IS_ADMIN(pd->pti);
+			break;
+		case PWATM_MODE_11_VPC:
+			pd->vci = tvb_get_ntohs(tvb, 1);
+			UPDATE_CUMULATIVE_VALUE(pd->cumulative.vci,pd->vci);
+			/*fallthrough*/
+		case PWATM_MODE_11_VCC:
+			tmp8	= (tvb_get_guint8(tvb, 0));
+			pd->cwb3.m	= (tmp8 >> 7) & 0x1;
+			pd->cwb3.v	= (tmp8 >> 6) & 0x1;
+			pd->cwb3.rsv	= (tmp8 >> 4) & 0x3;
+			pd->pti		= (tmp8 >> 1) & 0x7;
+			pd->cwb3.clp	= (tmp8 >> 0) & 0x1;
+			UPDATE_CUMULATIVE_VALUE(pd->cumulative.pti,pd->pti);
+			UPDATE_CUMULATIVE_VALUE(pd->cumulative.clp,pd->cwb3.clp);
+			/*
+			 * OAM cell mode is possible if packet contains atm cell (m == 0).
+			 */
+			pd->cell_mode_oam = PTI_IS_ADMIN(pd->pti) && (pd->cwb3.m == 0);
+			break;
+		case PWATM_MODE_AAL5_PDU:
+			tmp8		= (tvb_get_guint8(tvb, 0));
+			pd->cwb3.m	= (tmp8 >> 7) & 0x1;
+			pd->cwb3.v	= (tmp8 >> 6) & 0x1;
+			pd->cwb3.rsv	= (tmp8 >> 3) & 0x7;
+			pd->cwb3.u	= (tmp8 >> 2) & 0x1;
+			pd->cwb3.e	= (tmp8 >> 1) & 0x1;
+			pd->cwb3.clp	= (tmp8 >> 0) & 0x1;
+			UPDATE_CUMULATIVE_VALUE(pd->cumulative.clp,pd->cwb3.clp);
+			break;
+		default:
+			DISSECTOR_ASSERT_NOT_REACHED();
+			break;
+		}
+	}
+	
+	if (tree)
+	{
+		proto_item* item;
+		
+		item = proto_tree_add_item(tree, proto_cell_header, tvb
+			,0
+			,dissect_size
+			,FALSE);
+		if (PWATM_MODE_AAL5_PDU == pd->mode)
+		{
+			proto_item_set_text(item, "Third byte of Control Word"); /*overwrite heading line*/
+			/* cwb3 fileds are appended to CW heading line, not here */
+		}
+		else
+		{
+			proto_item_append_text(item," [%.3d]",pd->pw_cell_number);
+			proto_item_append_text(item,", ");
+			if (pd->vpi >= 0)
+				proto_item_append_text(item, "VPI:%.4u  ", (unsigned)(pd->vpi));
+			if (pd->vci >= 0)
+				proto_item_append_text(item, "VCI:%.5u  ", (unsigned)(pd->vci));
+			if (pd->pti >= 0)
+				proto_item_append_text(item, "PTI:%.1u  ", (unsigned)(pd->pti));
+			proto_item_append_text_cwb3_fields(item,pd);
+		}
+		
+		{	
+			proto_tree* tree;
+			tree = proto_item_add_subtree(item, ett_cell_header);
+			if (is_enough_data)
+			{
+				proto_item* item;
+				if (MODE_N1(pd->mode)
+				    || (pd->mode == PWATM_MODE_AAL5_SDU && pd->submode == PWATM_SUBMODE_ADMIN_CELL))
+				{
+					(void) proto_tree_add_uint(tree, hf_cell_h_vpi, tvb, 0, 2, (unsigned)pd->vpi);
+					(void) proto_tree_add_uint(tree, hf_cell_h_vci, tvb, 1, 3, (unsigned)pd->vci);
+
+					item = proto_tree_add_item(tree, hf_cell_h_pti, tvb, 3, 1, FALSE);
+					if (NULL == match_strval(pd->pti,atm_pt_vals))
+					{
+						expert_add_info_format(pinfo, item, PI_UNDECODED, PI_WARN,
+							"Unknown value of PTI field (%d) in the ATM cell header",
+							pd->pti);
+					}
+					else if (pd->mode == PWATM_MODE_AAL5_SDU && !PTI_IS_ADMIN(pd->pti))
+					{
+						expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR,
+							"ATM admin cell is transerred;"
+							" PTI field (%d) should be 4, 5 or 6.",
+							pd->pti);
+					}
+					
+					(void) proto_tree_add_item(tree, hf_cell_h_clp, tvb, 3, 1, FALSE);
+				}
+				else if (MODE_11_OR_AAL5_PDU(pd->mode))
+				{
+					item = proto_tree_add_item(tree, hf_cell_h_m  , tvb, 0, 1, FALSE);
+					if ((0 != pd->cwb3.m) && MODE_11(pd->mode))
+					{
+						expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR
+							,"1:1 mode:"
+							" M bit must be 0 to distinguish from AAL5 PDU mode");
+					}
+
+					item = proto_tree_add_item(tree, hf_cell_h_v  , tvb, 0, 1, FALSE);
+					if ((0 == pd->cwb3.v) && (PWATM_MODE_11_VPC == pd->mode))
+					{
+						expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR
+							,"1:1 VPC mode:"
+							" V bit must be 1 to indicate that VCI is present");
+					}
+					if ((0 != pd->cwb3.v) && (PWATM_MODE_11_VCC == pd->mode))
+					{
+						expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR
+							,"1:1 VCC mode:"
+							" V bit must be 0 to indicate that VCI is absent");
+					}
+					if ((0 != pd->cwb3.v) && (PWATM_MODE_AAL5_PDU == pd->mode))
+					{
+						expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR
+							,"AAL5 PDU mode:"
+							" V bit must be 0 to indicate that VCI is absent");
+					}
+					
+					item = proto_tree_add_item(tree
+						,(PWATM_MODE_AAL5_PDU == pd->mode)
+							? hf_aal5_pdu_rsv
+							: hf_cell_h_rsv
+						,tvb, 0, 1, FALSE);
+					if (0 != pd->cwb3.rsv)
+					{
+						expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR
+							,"Reserved bits in the 3rd byte of CW must be 0");
+					}
+					else
+					{
+				                PROTO_ITEM_SET_HIDDEN(item); /*...and show only in error cases */
+			                }
+			
+					if (MODE_11(pd->mode))
+					{
+						item = proto_tree_add_item(tree, hf_cell_h_pti, tvb, 0, 1, FALSE);
+						if (NULL == match_strval(pd->pti,atm_pt_vals))
+						{
+							expert_add_info_format(pinfo, item, PI_UNDECODED, PI_WARN,
+								"Unknown value of PTI field (%d) in the atm-specific byte"
+								,pd->pti);
+						}
+					}
+					else
+					{
+						(void) proto_tree_add_item(tree, hf_aal5_pdu_u, tvb, 0, 1, FALSE);
+						(void) proto_tree_add_item(tree, hf_aal5_pdu_e, tvb, 0, 1, FALSE);
+					}
+					
+					(void) proto_tree_add_item(tree, hf_cell_h_clp, tvb, 0, 1, FALSE);
+					
+					if (PWATM_MODE_11_VPC == pd->mode)
+					{
+						(void) proto_tree_add_uint(tree, hf_cell_h_vci, tvb, 1, 2
+							,(unsigned)pd->vci);
+					}
+				}
+				else
+				{
+					DISSECTOR_ASSERT_NOT_REACHED();
+				}
+			}
+			else
+			{
+				expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR
+					,"Not enough data (size: %d), impossible to decode"
+					,(int)dissect_size);
+			}
+		}
+	}
+	return dissect_size;
+}
+
+
+static
+int dissect_cell(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
+{
+	gboolean is_enough_data;
+	int dissect_size;
+		
+	{
+		gint size;
+		size = tvb_reported_length_remaining(tvb, 0);
+		if (size < SIZEOF_ATM_CELL_PAYLOAD)
+		{
+			is_enough_data = FALSE;
+			dissect_size = size;
+		}
+		else
+		{
+			is_enough_data = TRUE;
+			dissect_size = SIZEOF_ATM_CELL_PAYLOAD;
+		}
+	}
+
+	/*
+	 * NB: do not touch columns -- keep info from previous dissector
+	 */
+	
+	if (tree)
+	{
+		proto_item* item;
+		item = proto_tree_add_item(tree, proto_cell, tvb, 0, dissect_size, FALSE);
+		{
+			pwatm_private_data_t * pd;
+			pd = pinfo->private_data;
+			if (NULL != pd)
+			{
+				proto_item_append_text(item," [%.3d]",pd->pw_cell_number);
+			}
+		}
+		pwc_item_append_text_n_items(item,dissect_size,"byte");
+		if (!is_enough_data)
+		{
+			expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR
+				,"Bad length of cell payload: must be == %d"
+				,(int)SIZEOF_ATM_CELL_PAYLOAD);
+		}
+		
+		{
+			proto_tree* tree;
+			tvbuff_t* tvb_d;
+			tree = proto_item_add_subtree(item, ett_cell);
+			tvb_d = tvb_new_subset(tvb, 0, dissect_size, -1);
+			call_dissector(dh_data, tvb_d, pinfo, tree);
+			item = proto_tree_add_int(tree, hf_cell_payload_len, tvb, 0, 0, dissect_size);
+			PROTO_ITEM_SET_HIDDEN(item);
+		}
+	}
+	return dissect_size;
+}
+
+
+void proto_register_pw_atm_ata(void)
+{
+	static const value_string clp_vals[] = {
+		{ 0, "High priority" },
+		{ 1, "Low priority" },
+		{ 0, NULL }
+	};
+	static const value_string m_vals[] = {
+		{ 0, "ATM cell" },
+		{ 1, "AAL5 payload" },
+		{ 0, NULL }
+	};
+	static const value_string u_vals[] = {
+		{ 0, "This frame does not contain the last cell of AAL5 PDU" },
+		{ 1, "This frame contains the last cell of AAL5 PDU" },
+		{ 0, NULL }
+	};
+	static const value_string e_vals[] = {
+		{ 0, "Congestion is not experienced" },
+		{ 1, "Congestion is experienced for one or more ATM AAL5 cells" },
+		{ 0, NULL }
+	};
+	static hf_register_info hfa_cell_header[] = {
+		{ &hf_cell_h_vpi	,{"VPI"				,"atm.vpi"
+					,FT_UINT16	,BASE_DEC	,NULL           ,0
+					,NULL						,HFILL }}
+		,{ &hf_cell_h_vci	,{"VCI"				,"atm.vci"
+					,FT_UINT16	,BASE_DEC	,NULL		,0
+					,NULL						,HFILL }}
+		,{ &hf_cell_h_pti	,{"Payload Type"		,"atm.pti"
+					,FT_UINT8	,BASE_DEC	,VALS(atm_pt_vals),0x0e
+					,"The 3-bit Payload Type Identifier (PTI) incorporates ATM Layer"
+					" PTI coding of the cell.  These bits are set to the value of the"
+					" PTI of the encapsulated ATM cell."
+											,HFILL }}
+		,{ &hf_cell_h_clp	,{"Cell Loss Priority"		,"atm.clp"
+					,FT_UINT8	,BASE_DEC	,VALS(clp_vals)	,0x01
+					,"The Cell Loss Priority (CLP) field indicates CLP value"
+					" of the encapsulated cell."
+											,HFILL }}
+		,{ &hf_cell_h_m		,{"Transport Mode"		,"atm.pw_control_byte.m"
+					,FT_UINT8	,BASE_DEC	,VALS(m_vals)	,0x80
+					,"Bit (M) of the control byte indicates  whether the packet"
+					" contains an ATM cell or a frame payload. If set to 0,"
+					" the packet contains an ATM cell. If set to 1, the PDU"
+					" contains an AAL5 payload."			
+											,HFILL }}
+		,{ &hf_cell_h_v		,{"VCI Present"			,"atm.pw_control_byte.v"
+					,FT_BOOLEAN	,8		,TFS(&tfs_yes_no),0x40
+					,"Bit (V) of the control byte indicates whether the VCI field"
+					" is present in the packet. If set to 1, the VCI field is present"
+					" for the cell. If set to 0, no VCI field is present."
+											,HFILL }}
+		,{ &hf_cell_h_rsv	,{"Reserved bits"		,"atm.pw_control_byte.rsv"
+					,FT_UINT8	,BASE_DEC	,NULL		,0x30
+					,"The reserved bits should be set to 0 at the transmitter and"
+					" ignored upon reception."
+											,HFILL }}
+		,{ &hf_aal5_pdu_rsv	,{"Reserved bits"		,"atm.pw_control_byte.rsv"
+					,FT_UINT8	,BASE_DEC	,NULL		,0x38
+					,"The reserved bits should be set to 0 at the transmitter and"
+					" ignored upon reception."
+											,HFILL }}
+		,{ &hf_aal5_pdu_u	,{"U bit"			,"atm.pw_control_byte.u"
+					,FT_UINT8	,BASE_DEC	,VALS(u_vals)	,0x04
+					,"Indicates whether this frame contains the last cell of"
+					" an AAL5 PDU and represents the value of the ATM User-to-User"
+					" bit for the last ATM cell of the PSN frame. Note: The ATM"
+					" User-to-User bit is the least significant bit of the PTI"
+					" in the ATM header."
+											,HFILL }}
+		,{ &hf_aal5_pdu_e	,{"EFCI"			,"atm.pw_control_byte.efci"
+					,FT_UINT8	,BASE_DEC	,VALS(e_vals)	,0x02
+					,"EFCI is set to the EFCI state of the last cell of the"
+					" AAL5 PDU or AAL5 fragment. Note: The EFCI state is"
+					" indicated in the middle bit of each ATM cell's PTI."
+											,HFILL }}
+	};
+static hf_register_info hfa_cell[] = {
+	{&hf_cell_payload_len	,{"Length"			,"atm.cell.len"
+					,FT_INT32	,BASE_DEC	,NULL		,0
+					,NULL						,HFILL }}
+	};
+	
+	#define HF_INITIALIZER_NCELLS(hf_handle)\
+		{&(hf_handle)		,{"Number of good encapsulated cells","pw.atm.cells"\
+					,FT_INT32	,BASE_DEC	,NULL		,0\
+					,NULL						,HFILL }}
+
+	#define HF_INITIALIZER_PWTYPE(hf_handle,name)\
+		{ &hf_handle		,{name				,name\
+					,FT_BOOLEAN	,0		,NULL		,0x0\
+					,"Identifies type of ATM PW. May be used for filtering.",HFILL}}
+
+
+	static hf_register_info hfa_n1_nocw[] = {
+		 HF_INITIALIZER_NCELLS(hf_n1_nocw_ncells)
+		,HF_INITIALIZER_PWTYPE(hf_pw_type_n1_nocw,"pw.type.atm.n1nocw")
+	};
+
+	static hf_register_info hfa_n1_cw[] = {
+		 HF_INITIALIZER_NCELLS(hf_n1_cw_ncells)
+		,HF_INITIALIZER_PWTYPE(hf_pw_type_n1_cw,"pw.type.atm.n1cw")
+	};
+
+	static hf_register_info hfa_11_aal5pdu[] = {
+		 HF_INITIALIZER_NCELLS(hf_11_ncells)
+		,HF_INITIALIZER_PWTYPE(hf_pw_type_11_vcc,"pw.type.atm.11vcc")
+		,HF_INITIALIZER_PWTYPE(hf_pw_type_11_vpc,"pw.type.atm.11vpc")
+		,HF_INITIALIZER_PWTYPE(hf_pw_type_aal5_pdu,"pw.type.atm.aal5pdu")
+	};
+
+	static hf_register_info hfa_aal5_sdu[] = {
+		HF_INITIALIZER_PWTYPE(hf_pw_type_aal5_sdu,"pw.type.atm.aal5sdu")
+	};
+
+	static const value_string a5s_t_vals[] = {
+		{ 0, "AAL5 payload" },
+		{ 1, "ATM admin cell" },
+		{ 0, NULL }
+	};
+	
+	static const value_string a5s_e_vals[] = {
+		{ 0, "No congestion" },
+		{ 1, "Congestion experienced" },
+		{ 0, NULL }
+	};
+	
+	static hf_register_info hfa_cw[] = {
+		{ &hf_cw_bits03		,{"Bits 0 to 3"			,"pw.cw.bits03"
+					,FT_UINT8 	,BASE_HEX 	,NULL		,0xf0	
+					,NULL						,HFILL }}
+		,{ &hf_pref_cw_flags	,{"Flags"			,"pw.cw.flags"		
+					,FT_UINT8	,BASE_HEX	,NULL		,0x0f
+					,NULL 						,HFILL }}
+		,{ &hf_pref_cw_a5s_t	,{"Payload type"		,"atm.pt"		
+					,FT_UINT8	,BASE_DEC	,VALS(a5s_t_vals),0x08
+					,"Bit (T) of the control word indicates whether the packet contains"
+					" an ATM admin cell or an AAL5 payload. If T = 1, the packet"
+					" contains an ATM admin cell, encapsulated according to the N:1"
+					" cell relay encapsulation. If not set, the PDU"
+					" contains an AAL5 payload." 			
+											,HFILL }}
+		,{ &hf_pref_cw_a5s_e	,{"EFCI bit"			,"atm.efci"		
+					,FT_UINT8	,BASE_DEC	,VALS(a5s_e_vals),0x04
+					,"The ingress router sets this bit to 1 if the EFCI bit"
+					" of the final cell of those that transported the AAL5 CPCS-SDU is"
+					" set to 1, or if the EFCI bit of the single ATM cell to be"
+					" transported in the packet is set to 1. Otherwise, this bit"
+					" is set to 0."
+											,HFILL }}
+		,{ &hf_pref_cw_a5s_c	,{"CLP bit"			,"atm.clp"		
+					,FT_UINT8	,BASE_DEC	,VALS(clp_vals)	,0x02
+					,"The ingress router sets this bit to 1 if the CLP bit"
+					" of any of the ATM cells that transported the AAL5 CPCS-SDU is set"
+					" to 1, or if the CLP bit of the single ATM cell to be transported"
+					" in the packet is set to 1. Otherwise this bit is set to 0."
+											,HFILL }}
+		,{ &hf_pref_cw_a5s_u	,{"U bit (Command/Response)"	,"pw.cw.aal5sdu.u"		
+					,FT_UINT8	,BASE_DEC	,NULL		,0x01
+					,"When FRF.8.1 Frame Relay/ATM PVC Service Interworking [RFC3916]"
+					" traffic is being transported, the Least-Significant Bit of CPCS-UU"
+					" of the AAL5 CPCS-PDU may contain the Frame Relay C/R bit."
+					" The ingress router copies this bit here."
+											,HFILL }}
+		,{ &hf_pref_cw_rsv	,{"Reserved bits"		,"pw.cw.rsv"
+					,FT_UINT8	,BASE_DEC	,NULL		,0xc0
+					,NULL						,HFILL }}
+		,{ &hf_generic_cw_rsv	,{"Reserved bits"		,"pw.cw.rsv"
+					,FT_UINT8	,BASE_DEC	,NULL		,0x0f
+					,NULL						,HFILL }}
+		,{ &hf_pref_cw_len	,{"Length"			,"pw.cw.length"
+					,FT_UINT8	,BASE_DEC	,NULL		,0x3f
+					,NULL						,HFILL }}
+		,{ &hf_pref_cw_rsvlen	,{"Length (extended)"		,"pw.cw.length"
+					,FT_UINT8	,BASE_DEC	,NULL		,0xff
+					,NULL						,HFILL }}
+		,{ &hf_cw_seq		,{"Sequence number"		,"pw.cw.seqno"
+					,FT_UINT16	,BASE_DEC	,NULL		,0	
+					,NULL						,HFILL }}
+		,{ &hf_gen_cw_atmbyte	,{"ATM-specific byte"		,"pw.cw.3rd_byte"
+					,FT_UINT8	,BASE_HEX	,NULL		,0xFF	
+					,NULL						,HFILL }}
+	};
+	static gint *ett_array[] = {
+		&ett_encaps
+		,&ett_cw
+		,&ett_cell_header
+		,&ett_cell
+	};
+
+	proto_n1_cw =
+		proto_register_protocol(pwc_longname_pw_atm_n1_cw
+					,shortname_n1_cw
+					,"mplspwatmn1cw");
+	proto_11_or_aal5_pdu =
+		proto_register_protocol(pwc_longname_pw_atm_11_or_aal5_pdu
+					,shortname_11_or_aal5_pdu
+					,"mplspwatm11_or_aal5pdu");
+	proto_aal5_sdu =
+		proto_register_protocol(pwc_longname_pw_atm_aal5_sdu
+					,shortname_aal5_sdu
+					,"mplspwatmaal5sdu");
+	proto_n1_nocw =
+		proto_register_protocol(pwc_longname_pw_atm_n1_nocw
+					,shortname_n1_nocw
+					,"mplspwatmn1nocw");
+	proto_control_word =
+		proto_register_protocol("MPLS PW ATM Control Word"
+					,"MPLS PW ATM Control Word"
+					,"mplspwatmcontrolword");
+	proto_cell_header =
+		proto_register_protocol("MPLS PW ATM Cell Header"
+					,"MPLS PW ATM Cell Header"
+					,"mplspwatmcellheader");
+	proto_cell =
+		proto_register_protocol("ATM Cell"
+					,"ATM Cell"
+					,"mplspwatmcell");
+
+	proto_register_field_array( proto_cell	 		,hfa_cell	,array_length(hfa_cell));
+	proto_register_field_array( proto_cell_header		,hfa_cell_header,array_length(hfa_cell_header));
+	proto_register_field_array( proto_control_word		,hfa_cw		,array_length(hfa_cw));
+	proto_register_field_array( proto_n1_nocw		,hfa_n1_nocw	,array_length(hfa_n1_nocw));
+	proto_register_field_array( proto_n1_cw			,hfa_n1_cw	,array_length(hfa_n1_cw));
+	proto_register_field_array( proto_11_or_aal5_pdu	,hfa_11_aal5pdu	,array_length(hfa_11_aal5pdu));
+	proto_register_field_array( proto_aal5_sdu		,hfa_aal5_sdu	,array_length(hfa_aal5_sdu));
+
+	proto_register_subtree_array(ett_array, array_length(ett_array));
+	
+	register_dissector("mpls_pw_atm_aal5_sdu"	,dissect_aal5_sdu	,proto_aal5_sdu);
+	register_dissector("mpls_pw_atm_11_or_aal5_pdu"	,dissect_11_or_aal5_pdu	,proto_11_or_aal5_pdu);
+	register_dissector("mpls_pw_atm_n1_cw"		,dissect_n1_cw		,proto_n1_cw);
+	register_dissector("mpls_pw_atm_n1_nocw"	,dissect_n1_nocw	,proto_n1_nocw);
+	register_dissector("mpls_pw_atm_control_word"	,dissect_control_word	,proto_control_word);
+	new_register_dissector("mpls_pw_atm_cell"	,dissect_cell		,proto_cell);
+	new_register_dissector("mpls_pw_atm_cell_header",dissect_cell_header	,proto_cell_header);
+	{
+		static const char description_allow_cw_length_nonzero[] =
+			"Enable to allow non-zero Length in Control Word."
+			" This may be needed to correctly decode traffic from some legacy devices"
+			" which generate non-zero Length even if there is no padding in the packet."
+			" Note that Length should have proper value (dissector checks this anyway)."
+			"\n\n"
+			"Disable to blame all packets with CW.Length <> 0. This conforms to RFC4717."
+			;
+		static const char description_extend_cw_length_with_rsvd[] =
+			"Enable to use reserved bits (8..9) of Control Word as an extension of CW.Length."
+			" This may be needed to correctly decode traffic from some legacy devices"
+			" which uses reserved bits as extension of Length"
+			"\n\n"
+			"Disable to blame all packets with CW.Reserved <> 0. This conforms to RFC4717."
+			;
+		module_t * module_n1_cw;
+		module_t * module_aal5_sdu;
+		
+		module_n1_cw = prefs_register_protocol(proto_n1_cw,NULL);
+		prefs_register_bool_preference(module_n1_cw
+			,"allow_cw_length_nonzero"
+			,"Allow CW.Length <> 0"
+			,&description_allow_cw_length_nonzero[0]
+			,&pref_n1_cw_allow_cw_length_nonzero);
+		prefs_register_bool_preference(module_n1_cw
+			,"extend_cw_length_with_rsvd"
+			,"Use CW.Reserved as extension of CW.Length"
+			,&description_extend_cw_length_with_rsvd[0]
+			,&pref_n1_cw_extend_cw_length_with_rsvd);
+			
+		module_aal5_sdu = prefs_register_protocol(proto_aal5_sdu,NULL);
+		prefs_register_bool_preference(module_aal5_sdu
+			,"allow_cw_length_nonzero_aal5"
+			,"Allow CW.Length <> 0"
+			,&description_allow_cw_length_nonzero[0]
+			,&pref_aal5_sdu_allow_cw_length_nonzero);
+		prefs_register_bool_preference(module_aal5_sdu
+			,"extend_cw_length_with_rsvd_aal5"
+			,"Use CW.Reserved as extension of CW.Length"
+			,&description_extend_cw_length_with_rsvd[0]
+			,&pref_aal5_sdu_extend_cw_length_with_rsvd);
+	}
+}
+
+
+void proto_reg_handoff_pw_atm_ata(void)
+{
+	dissector_handle_t h;
+	h = find_dissector("mpls_pw_atm_n1_cw");
+	dissector_add( "mpls.label", LABEL_INVALID, h );
+	h = find_dissector("mpls_pw_atm_n1_nocw");
+	dissector_add( "mpls.label", LABEL_INVALID, h );
+	h = find_dissector("mpls_pw_atm_11_or_aal5_pdu");
+	dissector_add( "mpls.label", LABEL_INVALID, h );
+	h = find_dissector("mpls_pw_atm_aal5_sdu");
+	dissector_add( "mpls.label", LABEL_INVALID, h );
 
-        data_h = find_dissector("data");
-        atm_h = find_dissector("atm_4717");
+	dh_cell = find_dissector("mpls_pw_atm_cell");
+	dh_cell_header = find_dissector("mpls_pw_atm_cell_header");
+	dh_control_word = find_dissector("mpls_pw_atm_control_word");
+	dh_atm_truncated = find_dissector("atm_truncated");
+	dh_atm_untruncated = find_dissector("atm_untruncated");
+	dh_atm_oam_cell = find_dissector("atm_oam_cell");
+	dh_padding = find_dissector("pw_padding");
+	dh_data = find_dissector("data");
 }
diff --git a/epan/dissectors/packet-pw-atm.h b/epan/dissectors/packet-pw-atm.h
new file mode 100644
index 0000000000..d1b0346b25
--- /dev/null
+++ b/epan/dissectors/packet-pw-atm.h
@@ -0,0 +1,101 @@
+/* packet-pw-atm.h
+ * Interface of pw-atm module
+ * Copyright 2009, Artem Tamazov <artem.tamazov@tellabs.com>
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef PACKET_PW_ATM_H
+#define PACKET_PW_ATM_H
+
+#include "packet-pw-common.h"
+
+typedef enum {
+	PWATM_MODE_UNKNOWN = 0
+	,PWATM_MODE_N1_NOCW
+	,PWATM_MODE_N1_CW
+	,PWATM_MODE_11_VCC
+	,PWATM_MODE_11_VPC
+	,PWATM_MODE_AAL5_SDU
+	,PWATM_MODE_AAL5_PDU
+} pwatm_mode_t;
+
+typedef enum {
+	PWATM_SUBMODE_DEFAULT = 0
+	,PWATM_SUBMODE_ADMIN_CELL /*used in aal5_sdu dissector only*/
+} pwatm_submode_t;
+
+typedef struct {
+	int pw_cell_number;
+	pwc_packet_properties_t props;
+	gint packet_size;
+	pwatm_mode_t mode;
+	pwatm_submode_t submode;
+	struct {
+		/*
+		 * ATM-specific attributes which remain the same
+		 * across all the cells in the pw packet. Values are filled
+		 * by sub-dissectors and read by upper-level dissector.
+		 * Meanings of values:
+		 *   (-1) 	- value is unknown 
+		 *   (-2) 	- value is different among cells
+		 *   positive	- value is the same in all cells
+		 * Machinery is implemented in the UPDATE_CUMULATIVE_VALUE macro.
+		 */
+		gint32 vpi;
+		gint32 vci;
+		gint32 clp;
+		gint32 pti;
+	} cumulative;
+	gint32 vpi; /*-1 if unknown*/
+	gint32 vci; /*-1 if unknown*/
+	gint32 pti; /*-1 if unknown*/
+	struct {
+		/* 
+		 * Some fields from 3rd byte of CW. Filled by cell_header dissector.
+		 * In in AAL5 PDU mode, this allows control_word dissector to print
+		 * these values in the CW heading line in the tree.
+		 * Meanings of values:
+		 *   (-1) 	- value is unknown 
+		 */
+		gint32 m;
+		gint32 v;
+		gint32 rsv;
+		gint32 u;
+		gint32 e;
+		gint32 clp;
+	} cwb3; 
+	gboolean aal5_sdu_frame_relay_cr_bit; /*see rfc4717 10.1*/
+	gboolean cell_mode_oam; /*atm admin cell*/
+	gboolean enable_fill_columns_by_atm_dissector;
+} pwatm_private_data_t;
+
+
+#define PWATM_PRIVATE_DATA_T_INITIALIZER {		\
+	0, PWC_PACKET_PROPERTIES_T_INITIALIZER, 0	\
+	,PWATM_MODE_UNKNOWN, PWATM_SUBMODE_DEFAULT	\
+	,{-1, -1, -1, -1 } 				\
+	,-1, -1, -1 					\
+	,{-1, -1, -1, -1, -1, -1 }			\
+	,FALSE, FALSE, TRUE				\
+	}
+
+#endif /*PACKET_PW_ATM_H*/
diff --git a/epan/dissectors/packet-pw-cesopsn.c b/epan/dissectors/packet-pw-cesopsn.c
index e8656adb1a..be77883010 100644
--- a/epan/dissectors/packet-pw-cesopsn.c
+++ b/epan/dissectors/packet-pw-cesopsn.c
@@ -56,12 +56,12 @@ static int hf_cw_frg = -1;
 static int hf_cw_len = -1;
 static int hf_cw_seq = -1;
 static int hf_payload = -1;
-static int hf_padding = -1;
-static int hf_padding_f = -1;
+static int hf_payload_l = -1;
 
 static dissector_handle_t data_handle;
+static dissector_handle_t pw_padding_handle;
 
-static const char pwc_longname_pw_cesopsn[] = "CESoPSN basic NxDS0 mode (no RTP support)";
+const char pwc_longname_pw_cesopsn[] = "CESoPSN basic NxDS0 mode (no RTP support)";
 static const char shortname[] = "CESoPSN basic (no RTP)";
 
 static const value_string vals_cw_lm[] = {
@@ -121,7 +121,7 @@ static void dissect_pw_cesopsn( tvbuff_t * tvb_original, packet_info * pinfo, pr
 
 	/* check how "good" is this packet */
 	/* also decide payload length from packet size and CW */
-	properties = 0;
+	properties = PWC_PACKET_PROPERTIES_T_INITIALIZER;
 	if (0 != (tvb_get_guint8(tvb_original, 0) & 0xf0 /*bits03*/))
 	{
 		properties |= PWC_CW_BAD_BITS03;
@@ -188,7 +188,7 @@ static void dissect_pw_cesopsn( tvbuff_t * tvb_original, packet_info * pinfo, pr
 	{
 		guint8 cw_lm;
 		cw_lm = tvb_get_guint8(tvb_original, 0) & 0x0b /*l+mod*/;
-		if (!pwc_value_listed_in_vals(cw_lm, vals_cw_lm))
+		if (NULL == match_strval(cw_lm, vals_cw_lm))
 		{
 			properties |= PWC_CW_SUSPECT_LM;
 		}
@@ -348,6 +348,9 @@ static void dissect_pw_cesopsn( tvbuff_t * tvb_original, packet_info * pinfo, pr
 				}
 				tree = proto_item_add_subtree(item, ett);
 				call_dissector(data_handle, tvb, pinfo, tree);
+				item = proto_tree_add_int(tree, hf_payload_l, tvb, 0, 0
+					,(int)payload_size); /* allow filtering */
+				PROTO_ITEM_SET_HIDDEN(item);
 			}
 		}
 		
@@ -357,12 +360,9 @@ static void dissect_pw_cesopsn( tvbuff_t * tvb_original, packet_info * pinfo, pr
 			proto_tree* tree;
 			tree = proto_item_add_subtree(item, ett);
 			{
-				proto_item* item;
 				tvbuff_t* tvb;
 				tvb = tvb_new_subset(tvb_original, PWC_SIZEOF_CW + payload_size, padding_size, -1);
-				item = proto_tree_add_item(tree, hf_padding, tvb, 0, -1, FALSE);
-				pwc_item_append_text_n_items(item,(int)padding_size,"octet");
-				call_dissector(data_handle, tvb, pinfo, tree);
+				call_dissector(pw_padding_handle, tvb, pinfo, tree);
 			}
 		}	
 	}
@@ -396,11 +396,8 @@ void proto_register_pw_cesopsn(void)
 		,{&hf_payload	,{"TDM payload"			,"pwcesopsn.payload"	
 				,FT_BYTES			,BASE_NONE		,NULL			
 				,0				,NULL			,HFILL }}
-		,{&hf_padding	,{"Padding"			,"pwcesopsn.padding"	
-				,FT_BYTES			,BASE_NONE		,NULL			
-				,0				,NULL			,HFILL }}
-		,{&hf_padding_f	,{"Padding (formatted)"		,""
-				,FT_BYTES			,BASE_NONE		,NULL
+		,{&hf_payload_l	,{"TDM payload length"		,"pwcesopsn.payload.len"
+				,FT_INT32			,BASE_DEC		,NULL
 				,0				,NULL			,HFILL }}
 	};
 	
@@ -420,6 +417,7 @@ void proto_reg_handoff_pw_cesopsn(void)
 	dissector_handle_t h;
 	h = find_dissector("pw_cesopsn");
 	data_handle = find_dissector("data");
+	pw_padding_handle = find_dissector("pw_padding");
 	dissector_add("mpls.label", LABEL_INVALID, h);
 	return;
 }
diff --git a/epan/dissectors/packet-pw-common.c b/epan/dissectors/packet-pw-common.c
index 21f88ef016..e879e02e41 100644
--- a/epan/dissectors/packet-pw-common.c
+++ b/epan/dissectors/packet-pw-common.c
@@ -28,6 +28,7 @@
 #endif
 
 #include <string.h>
+#include <epan/packet.h>
 #include "packet-pw-common.h"
 
 static const char string_ok[] = "Ok";
@@ -57,22 +58,6 @@ pwc_vals_cw_frag[] = {
 };
 
 
-int pwc_value_listed_in_vals(const guint32 val, const value_string * vals)
-{
-	if (NULL != vals)
-	{
-		while (vals->strptr != NULL)
-		{
-			if (val == vals->value)
-			{
-				return (1==1);
-			}
-			++vals;
-		}
-	}
-	return 0;
-}
-
 void pwc_item_append_cw(proto_item* item, const guint32 cw, const gboolean append_text)
 {
 	if (item != NULL)
@@ -90,8 +75,61 @@ void pwc_item_append_cw(proto_item* item, const guint32 cw, const gboolean appen
 void pwc_item_append_text_n_items(proto_item* item, const int n, const char * const item_text)
 {
 	assert(item != 0);
-	proto_item_append_text(item, ", %d %s%s", n, item_text, plurality(n,"","s"));
+	if (n >=0)
+	{
+		proto_item_append_text(item, ", %d %s%s", n, item_text, plurality(n,"","s"));
+	}
+	return;
+}
+
+
+static gint proto_pw_padding = -1;
+static gint ett = -1;
+static int hf_padding_len = -1;
+static dissector_handle_t dh_data;
+
+static
+void dissect_pw_padding(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
+{
+	/* do not touch columns */
+	if (tree)
+	{
+		gint size;
+		proto_item* item;
+		size = tvb_reported_length_remaining(tvb, 0);
+		item = proto_tree_add_item(tree, proto_pw_padding, tvb, 0, -1, FALSE);
+		pwc_item_append_text_n_items(item,size,"byte");
+		{
+			proto_tree* tree;
+			tree = proto_item_add_subtree(item, ett);
+			call_dissector(dh_data, tvb, pinfo, tree);
+			item = proto_tree_add_int(tree, hf_padding_len, tvb, 0, 0, size);
+			PROTO_ITEM_SET_HIDDEN(item); /*allow filtering*/
+		}
+	}
+	return;
+}
+
+void proto_register_pw_padding(void)
+{
+	static hf_register_info hfpadding[] = {
+		{&hf_padding_len	,{"Length"			,"pw.padding.len"
+					,FT_INT32	,BASE_DEC	,NULL		,0
+					,NULL						,HFILL }}
+	};
+	static gint *ett_array[] = {
+		&ett
+	};
+	proto_pw_padding = proto_register_protocol("Pseudowire Padding","PW Padding","pwpadding");
+	proto_register_field_array(proto_pw_padding, hfpadding, array_length(hfpadding));
+	proto_register_subtree_array(ett_array, array_length(ett_array));
+	register_dissector("pw_padding", dissect_pw_padding, proto_pw_padding);
 	return;
 }
 
 
+void proto_reg_handoff_pw_padding(void)
+{
+	dh_data = find_dissector("data");
+	return;
+}
diff --git a/epan/dissectors/packet-pw-common.h b/epan/dissectors/packet-pw-common.h
index 81f6b99a73..bf8b99060b 100644
--- a/epan/dissectors/packet-pw-common.h
+++ b/epan/dissectors/packet-pw-common.h
@@ -31,6 +31,13 @@
 
 #define PWC_SIZEOF_CW 4
 
+extern const char pwc_longname_pw_satop[];
+extern const char pwc_longname_pw_cesopsn[];
+extern const char pwc_longname_pw_atm_n1_cw[];
+extern const char pwc_longname_pw_atm_n1_nocw[];
+extern const char pwc_longname_pw_atm_11_or_aal5_pdu[];
+extern const char pwc_longname_pw_atm_aal5_sdu[];
+
 extern const value_string pwc_vals_cw_l_bit[];
 extern const value_string pwc_vals_cw_r_bit[];
 extern const value_string pwc_vals_cw_frag[];
@@ -42,19 +49,26 @@ typedef enum {
 	,PWC_CW_BAD_LEN_MUST_BE_0	= 1 << 3
 	,PWC_CW_BAD_FRAG 		= 1 << 4
 	,PWC_CW_BAD_RSV 		= 1 << 5
+	,PWC_CW_BAD_FLAGS 		= 1 << 8
+	,PWC_CW_BAD_PAYLEN_LE_0		= 1 << 9
+	,PWC_CW_BAD_PADDING_NE_0	= 1 << 10
 	,PWC_ANYOF_CW_BAD	= PWC_CW_BAD_BITS03
 				+ PWC_CW_BAD_PAYLEN_LT_0
 				+ PWC_CW_BAD_PAYLEN_GT_PACKET
 				+ PWC_CW_BAD_LEN_MUST_BE_0
 				+ PWC_CW_BAD_FRAG
 				+ PWC_CW_BAD_RSV
+				+ PWC_CW_BAD_FLAGS
+				+ PWC_CW_BAD_PAYLEN_LE_0
+				+ PWC_CW_BAD_PADDING_NE_0
 	,PWC_CW_SUSPECT_LM		= 1 << 6				
 	,PWC_ANYOF_CW_SUSPECT	= PWC_CW_SUSPECT_LM
 	,PWC_PAY_SIZE_BAD		= 1 << 7
-} pwc_packet_properties_t;
+}
+pwc_packet_properties_t;
+#define PWC_PACKET_PROPERTIES_T_INITIALIZER 0
 
 extern void pwc_item_append_cw(proto_item* item, const guint32 cw, const gboolean append_text);
 extern void pwc_item_append_text_n_items(proto_item* item, const int n, const char * const item_text);
-extern int pwc_value_listed_in_vals(const guint32 val, const value_string * vals);
 
 #endif
diff --git a/epan/dissectors/packet-pw-satop.c b/epan/dissectors/packet-pw-satop.c
index 65eacb6a9b..5db068eb1f 100644
--- a/epan/dissectors/packet-pw-satop.c
+++ b/epan/dissectors/packet-pw-satop.c
@@ -56,12 +56,12 @@ static int hf_cw_frg = -1;
 static int hf_cw_len = -1;
 static int hf_cw_seq = -1;
 static int hf_payload = -1;
-static int hf_padding = -1;
-static int hf_padding_f = -1;
+static int hf_payload_l = -1;
 
 static dissector_handle_t data_handle;
+static dissector_handle_t pw_padding_handle;
 
-static const char pwc_longname_pw_satop[] = "SAToP (no RTP support)";
+const char pwc_longname_pw_satop[] = "SAToP (no RTP support)";
 static const char shortname[] = "SAToP (no RTP)";
 
 
@@ -80,7 +80,7 @@ static void dissect_pw_satop(tvbuff_t * tvb_original, packet_info * pinfo, proto
 		,PAY_LIKE_OCTET_ALIGNED_T1
 	} payload_properties;
 
-	properties = 0;
+	properties = PWC_PACKET_PROPERTIES_T_INITIALIZER;
 	payload_properties = PAY_NO_IDEA;
 	packet_size = tvb_reported_length_remaining(tvb_original, 0);
 	/*
@@ -364,6 +364,9 @@ static void dissect_pw_satop(tvbuff_t * tvb_original, packet_info * pinfo, proto
 					proto_item_append_text(item, "%s", s);
 					tree = proto_item_add_subtree(item, ett);
 					call_dissector(data_handle, tvb, pinfo, tree);
+					item = proto_tree_add_int(tree, hf_payload_l, tvb, 0, 0
+						,(int)payload_size); /* allow filtering */
+					PROTO_ITEM_SET_HIDDEN(item);
 				}
 			}
 		}
@@ -374,16 +377,9 @@ static void dissect_pw_satop(tvbuff_t * tvb_original, packet_info * pinfo, proto
 			proto_tree* tree;
 			tree = proto_item_add_subtree(item, ett);
 			{
-				proto_item* item;
 				tvbuff_t* tvb;
 				tvb = tvb_new_subset(tvb_original, PWC_SIZEOF_CW + payload_size, padding_size, -1);
-				item = proto_tree_add_item(tree, hf_padding, tvb, 0, -1, FALSE);
-				pwc_item_append_text_n_items(item,(int)padding_size,"octet");
-				{
-					proto_tree* tree;
-					tree = proto_item_add_subtree(item, ett);
-					call_dissector(data_handle, tvb, pinfo, tree);
-				}
+				call_dissector(pw_padding_handle, tvb, pinfo, tree);
 			}
 		}	
 	}
@@ -421,11 +417,8 @@ void proto_register_pw_satop(void)
 		,{&hf_payload	,{"TDM payload"			,"pwsatop.payload"	
 				,FT_BYTES			,BASE_NONE		,NULL			
 				,0				,NULL			,HFILL }}
-		,{&hf_padding	,{"Padding"			,"pwsatop.padding"	
-				,FT_BYTES			,BASE_NONE		,NULL			
-				,0				,NULL			,HFILL }}
-		,{&hf_padding_f	,{"Padding (formatted)"		,""
-				,FT_BYTES			,BASE_NONE		,NULL
+		,{&hf_payload_l	,{"TDM payload length"		,"pwsatop.payload.len"
+				,FT_INT32			,BASE_DEC		,NULL
 				,0				,NULL			,HFILL }}
 	};
 	
@@ -445,5 +438,6 @@ void proto_reg_handoff_pw_satop(void)
 	dissector_handle_t h;
 	h = find_dissector("pw_satop");
 	data_handle = find_dissector("data");
+	pw_padding_handle = find_dissector("pw_padding");
 	dissector_add("mpls.label", LABEL_INVALID, h);
 }
diff --git a/epan/packet_info.h b/epan/packet_info.h
index 394167badf..f5da1e1c54 100644
--- a/epan/packet_info.h
+++ b/epan/packet_info.h
@@ -187,28 +187,6 @@ typedef struct _packet_info {
   struct _sccp_msg_info_t* sccp_info;
   guint16 clnp_srcref;      /* clnp/cotp source reference (can't use srcport, this would confuse tpkt) */
   guint16 clnp_dstref;      /* clnp/cotp destination reference (can't use dstport, this would confuse tpkt) */
-  guint8 pw_atm_encap_type; /* FF: RFC 4717 is devilish, it describes many
-                             * different types of ATM->PW encapsulation.
-                             * None of which can correctly be interpreted by
-                             * the packet-atm.c dissector.  Thus I have to
-                             * pass some info from packet-pw-atm.c to packet-
-                             * -atm.c, and augment/change packet-atm.c
-                             * dissector.
-                             *
-                             * 0: RFC4717::Sec.  9, ATM One-to-One Cell Mode
-                             * 1: RFC4717::Sec.  8, ATM N-to-One Cell Mode
-                             * 2: RFC4717::Sec. 10, ATM AAL5 CPCS-SDU Mode
-                             * 3: RFC4717::Sec. 11, ATM AAL5 PDU Frame Mode
-                             */
-  guint16 pw_atm_flags;     /* FF: all flags defined in RFC4717 compacted in a
-                             * single guint16.
-                             *
-                             * T, E, C, U, M, V, PTI, C  flag name
-                             * 9  8  7  6  5  4  321  0  position
-                             */
-  guint16 pw_atm_ncells;    /* FF: number of cells fitted in a single
-                             * PW frame.
-                             */
 
   guint16 zbee_cluster_id;  /* ZigBee cluster ID, an application-specific message identifier that
                              * happens to be included in the transport (APS) layer header.