Dissect a whole pile of Q.931 information elements.

svn path=/trunk/; revision=1023

1 files changed, 1850 insertions, 137 deletions

diff --git a/packet-q931.c b/packet-q931.c
index ec6e3016e0..960bedb4c4 100644
--- a/packet-q931.c
+++ b/packet-q931.c
@@ -2,7 +2,7 @@
  * Routines for Q.931 frame disassembly
  * Guy Harris <guy@alum.mit.edu>
  *
- * $Id: packet-q931.c,v 1.4 1999/11/13 02:07:59 guy Exp $
+ * $Id: packet-q931.c,v 1.5 1999/11/13 10:13:24 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -46,6 +46,7 @@
  * http://freesoft.org/CIE/Topics/126.htm
  * http://noc.comstar.ru/miscdocs/ascend-faq-cause-codes.html
  * http://www.andrews-arnold.co.uk/isdn/q931cause.html
+ * http://www.tulatelecom.ru/staff/german/DSSHelp/MessList/InfEl/InfElList.html
  */
 
 int proto_q931 = -1;
@@ -140,15 +141,20 @@ static const value_string q931_message_type_vals[] = {
 #define	Q931_IE_SO_IE_MASK		0x0F	/* IE mask */
 
 #define	Q931_IE_SHIFT			0x90
+#define	Q931_IE_SHIFT_LOCKING		0x08	/* locking shift */
+#define	Q931_IE_SHIFT_CODESET		0x0F	/* codeset */
+
 #define	Q931_IE_MORE_DATA_OR_SEND_COMP	0xA0	/* More Data or Sending Complete */
 #define	Q931_IE_MORE_DATA		0xA0
 #define	Q931_IE_SENDING_COMPLETE	0xA1
+
 #define	Q931_IE_CONGESTION_LEVEL	0xB0
 #define	Q931_IE_REPEAT_INDICATOR	0xD0
 
 /*
  * Variable-length IEs.
  */
+#define	Q931_IE_VL_EXTENSION		0x80	/* Extension flag */
 
 /*
  * Codeset 0 (default).
@@ -179,6 +185,8 @@ static const value_string q931_message_type_vals[] = {
 #define	Q931_IE_PL_BINARY_PARAMETERS	0x44	/* Packet layer binary parameters */
 #define	Q931_IE_PL_WINDOW_SIZE		0x45	/* Packet layer Window Size */
 #define	Q931_IE_PL_SIZE			0x46	/* Packet layer Size */
+#define	Q931_IE_CUG			0x47	/* Closed user group */
+#define	Q931_IE_REVERSE_CHARGE_IND	0x4A	/* Reverse charging indication */
 #define	Q931_IE_CALLING_PARTY_NUMBER	0x6C	/* Calling Party Number */
 #define	Q931_IE_CALLING_PARTY_SUBADDR	0x6D	/* Calling Party Subaddress */
 #define	Q931_IE_CALLED_PARTY_NUMBER	0x70	/* Called Party Number */
@@ -253,6 +261,8 @@ static const value_string q931_info_element_vals[] = {
 	{ Q931_IE_PL_BINARY_PARAMETERS,		"Packet layer binary parameters" },
 	{ Q931_IE_PL_WINDOW_SIZE,		"Packet layer window size" },
 	{ Q931_IE_PL_SIZE,			"Packet layer size" },
+	{ Q931_IE_CUG,				"Closed user group" },
+	{ Q931_IE_REVERSE_CHARGE_IND,		"Reverse charging indication" },
 	{ Q931_IE_CALLING_PARTY_NUMBER,		"Calling party number" },
 	{ Q931_IE_CALLING_PARTY_SUBADDR,	"Calling party subaddress" },
 	{ Q931_IE_CALLED_PARTY_NUMBER,		"Called party number" },
@@ -275,112 +285,1660 @@ static const value_string q931_info_element_vals[] = {
 	{ 0,					NULL }
 };
 
+static const value_string q931_congestion_level_vals[] = {
+	{ 0x0, "Receiver ready" },
+	{ 0xF, "Receiver not ready" },
+	{ 0,   NULL }
+};
+
+static const value_string q931_repeat_indication_vals[] = {
+	{ 0x2, "Prioritized list" },
+	{ 0,   NULL }
+};
+
+/*
+ * ITU-standardized coding.
+ */
+#define	Q931_ITU_STANDARDIZED_CODING	0x00
+
+/*
+ * Dissect a Segmented message information element.
+ */
+static void
+dissect_q931_segmented_message_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	if (len != 2) {
+		proto_tree_add_text(tree, offset, len,
+		    "Segmented message: length is %d, should be 2\n", len);
+		return;
+	}
+	if (pd[offset] & 0x80) {
+		proto_tree_add_text(tree, offset, 1,
+		    "First segment: %u segments remaining",
+		    pd[offset] & 0x7F);
+	} else {
+		proto_tree_add_text(tree, offset, 1,
+		    "Not first segment: %u segments remaining",
+		    pd[offset] & 0x7F);
+	}
+	proto_tree_add_text(tree, offset + 1, 1,
+	    "Segmented message type: %u\n", pd[offset + 1]);
+}
+
+/*
+ * Dissect a Bearer capability or Low-layer compatibility information element.
+ */
+static const value_string q931_bc_coding_standard_vals[] = {
+	{ 0x00, "ITU standardized coding" },
+	{ 0x20, "ISO/IEC standard" },
+	{ 0x40, "National standard" },
+	{ 0x60, "Standard defined for this particular network" },
+	{ 0,    NULL }
+};
+
+static const value_string q931_information_transfer_capability_vals[] = {
+	{ 0x00, "Speech" },
+	{ 0x08, "Unrestricted digital information" },
+	{ 0x09, "Restricted digital information" },
+	{ 0x10, "3.1 kHz audio" },
+	{ 0x11, "Unrestricted digital information with tones/announcements" },
+	{ 0x18, "Video" },
+	{ 0,    NULL }
+};
+	
+static const value_string q931_transfer_mode_vals[] = {
+	{ 0x00, "Circuit mode" },
+	{ 0x40, "Packet mode" },
+	{ 0,    NULL }
+};
+
+#define	Q931_IT_RATE_MULTIRATE	0x18
+
+static const value_string q931_information_transfer_rate_vals[] = {
+	{ 0x00,				"Packet mode" },
+	{ 0x10,				"64 kbit/s" },
+	{ 0x11,				"2 x 64 kbit/s" },
+	{ 0x13,				"384 kbit/s" },
+	{ 0x15,				"1536 kbit/s" },
+	{ 0x17,				"1920 kbit/s" },
+	{ Q931_IT_RATE_MULTIRATE,	"Multirate (64 kbit/s base rate)" },
+	{ 0,				NULL }
+};
+	
+static const value_string q931_uil1_vals[] = {
+	{ 0x01, "V.110/X.30 rate adaptation" },
+	{ 0x02, "Recommendation G.711 u-law" },
+	{ 0x03, "Recommendation G.711 A-law" },
+	{ 0x04, "Recommendation G.721 32 kbit/s ADPCM and Recommendation I.460" },
+	{ 0x05, "Recommendation G.722 and G.725 7 kHz audio" },
+	{ 0x06, "Recommendation G.7xx 384 kbit/s video" },
+	{ 0x07, "Non-ITU-standardized rate adaptation" },
+	{ 0x08, "V.120 rate adaptation" },
+	{ 0x09, "X.31 HDLC flag stuffing" },
+	{ 0,    NULL },
+};
+
+static const value_string q931_l1_user_rate_vals[] = {
+	{ 0x00, "Rate indicated by E-bits" },
+	{ 0x01, "0.6 kbit/s" },
+	{ 0x02, "1.2 kbit/s" },
+	{ 0x03, "2.4 kbit/s" },
+	{ 0x04, "3.6 kbit/s" },
+	{ 0x05, "4.8 kbit/s" },
+	{ 0x06, "7.2 kbit/s" },
+	{ 0x07, "8 kbit/s" },
+	{ 0x08, "9.6 kbit/s" },
+	{ 0x09, "14.4 kbit/s" },
+	{ 0x0A, "16 kbit/s" },
+	{ 0x0B, "19.2 kbit/s" },
+	{ 0x0C, "32 kbit/s" },
+	{ 0x0E, "48 kbit/s" },
+	{ 0x0F, "56 kbit/s" },
+	{ 0x10, "64 kbit/s "},
+	{ 0x15, "0.1345 kbit/s" },
+	{ 0x16, "0.100 kbit/s" },
+	{ 0x17, "0.075/1.2 kbit/s" },
+	{ 0x18, "1.2/0.075 kbit/s" },
+	{ 0x19, "0.050 kbit/s" },
+	{ 0x1A, "0.075 kbit/s" },
+	{ 0x1B, "0.110 kbit/s" },
+	{ 0x1C, "0.150 kbit/s" },
+	{ 0x1D, "0.200 kbit/s" },
+	{ 0x1E, "0.300 kbit/s" },
+	{ 0x1F, "12 kbit/s" },
+	{ 0,    NULL }
+};
+
+static const value_string q931_l1_intermediate_rate_vals[] = {
+	{ 0x20, "8 kbit/s" },
+	{ 0x40, "16 kbit/s" },
+	{ 0x60, "32 kbit/s" },
+	{ 0,    NULL }
+};
+
+static const value_string q931_l1_stop_bits_vals[] = {
+	{ 0x20, "1" },
+	{ 0x40, "1.5" },
+	{ 0x60, "2" },
+	{ 0,    NULL }
+};
+
+static const value_string q931_l1_data_bits_vals[] = {
+	{ 0x08, "5" },
+	{ 0x10, "7" },
+	{ 0x18, "8" },
+	{ 0,    NULL }
+};
+
+static const value_string q931_l1_parity_vals[] = {
+	{ 0x00, "Odd" },
+	{ 0x02, "Even" },
+	{ 0x03, "None" },
+	{ 0x04, "Forced to 0" },
+	{ 0x05, "Forced to 1" },
+	{ 0,    NULL }
+};
+
+static const value_string q931_l1_modem_type_vals[] = {
+	{ 0x11, "V.21" },
+	{ 0x12, "V.22" },
+	{ 0x13, "V.22 bis" },
+	{ 0x14, "V.23" },
+	{ 0x15, "V.26" },
+	{ 0x16, "V.26 bis" },
+	{ 0x17, "V.26 ter" },
+	{ 0x18, "V.27" },
+	{ 0x19, "V.27 bis" },
+	{ 0x1A, "V.27 ter" },
+	{ 0x1B, "V.29" },
+	{ 0x1C, "V.32" },
+	{ 0,    NULL }
+};
+
+#define	Q931_UIL2_USER_SPEC	0x10
+
+static const value_string q931_uil2_vals[] = {
+	{ 0x01,			"Basic mode ISO 1745" },
+	{ 0x02,			"Q.921/I.441" },	/* LAPD */
+	{ 0x06,			"X.25, link layer" },	/* LAPB */
+	{ 0x07,			"X.25 multilink" },	/* or 0x0F? */
+	{ 0x08,			"T.71 Extended LAPB" },
+	{ 0x09,			"HDLC ARM" },
+	{ 0x0A,			"HDLC NRM" },
+	{ 0x0B,			"HDLC ABM" },
+	{ 0x0C,			"ISO 8802/2 LLC" },
+	{ 0x0D,			"X.75 Single Link Procedure" },
+	{ 0x0E,			"Q.922" },
+	{ 0x0F,			"Core aspects of Q.922" },
+	{ Q931_UIL2_USER_SPEC,	"User-specified" },
+	{ 0x11,			"ISO 7776 DTE-DTE operation" },
+	{ 0,			NULL }
+};
+
+static const value_string q931_mode_vals[] = {
+	{ 0x20, "Normal mode" },
+	{ 0x40, "Extended mode" },
+	{ 0,    NULL }
+};
+
+#define	Q931_UIL3_X25_PL	0x06
+#define	Q931_UIL3_ISO_8208	0x07	/* X.25-based */
+#define	Q931_UIL3_X223		0x08	/* X.25-based */
+#define	Q931_UIL3_USER_SPEC	0x10
+
+static const value_string q931_uil3_vals[] = {
+	{ 0x02,			"Q.931/I.451" },
+	{ Q931_UIL3_X25_PL,	"X.25, packet layer" },
+	{ Q931_UIL3_ISO_8208,	"ISO/IEC 8208" },
+	{ Q931_UIL3_X223,	"X.223/ISO 8878" },
+	{ 0x09,			"ISO/IEC 8473" },
+	{ 0x0A,			"T.70" },
+	{ 0x0B,			"ISO/IEC TR 9577" },
+	{ Q931_UIL3_USER_SPEC,	"User-specified" },
+	{ 0,			NULL }
+};
+
+static void
+dissect_q931_bearer_capability_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	guint8 octet;
+	guint8 coding_standard;
+	guint8 it_rate;
+	guint8 modem_type;
+	guint8 uil2_protocol;
+	guint8 uil3_protocol;
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	coding_standard = octet & 0x60;
+	proto_tree_add_text(tree, offset, 1,
+	    "Coding standard: %s",
+	    val_to_str(coding_standard, q931_bc_coding_standard_vals, NULL));
+	if (coding_standard != Q931_ITU_STANDARDIZED_CODING) {
+		/*
+		 * We don't know how the bearer capability is encoded,
+		 * so just dump it as data and be done with it.
+		 */
+		proto_tree_add_text(tree, offset,
+		    len, "Data: %s", bytes_to_str(&pd[offset], len));
+		return;
+	}
+	proto_tree_add_text(tree, offset, 1,
+	    "Information transfer capability: %s",
+	    val_to_str(octet & 0x1F, q931_information_transfer_capability_vals,
+	      "Unknown (0x%02X)"));
+	offset += 1;
+	len -= 1;
+
+	/*
+	 * XXX - only in Low-layer compatibility information element.
+	 */
+	if (!(octet & Q931_IE_VL_EXTENSION)) {
+		if (len == 0)
+			return;
+		octet = pd[offset];
+		proto_tree_add_text(tree, offset, 1,
+		    "Out-band negotiation %spossible",
+		    (octet & 0x40) ? "" : "not ");
+		offset += 1;
+		len -= 1;
+	}
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	proto_tree_add_text(tree, offset, 1,
+	    "Transfer mode: %s",
+	    val_to_str(octet & 0x60, q931_transfer_mode_vals,
+	      "Unknown (0x%02X)"));
+	it_rate = octet & 0x1F;
+	proto_tree_add_text(tree, offset, 1,
+	    "Information transfer rate: %s",
+	    val_to_str(it_rate, q931_information_transfer_rate_vals,
+	      "Unknown (0x%02X)"));
+	offset += 1;
+	len -= 1;
+
+	if (it_rate == Q931_IT_RATE_MULTIRATE) {
+		if (len == 0)
+			return;
+		proto_tree_add_text(tree, offset, 1, "Rate multiplier: %u", pd[offset]);
+		offset += 1;
+		len -= 1;
+	}
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	if ((octet & 0x60) == 0x20) {
+		/*
+		 * Layer 1 information.
+		 */
+		proto_tree_add_text(tree, offset, 1,
+		    "User information layer 1 protocol: %s",
+		    val_to_str(octet & 0x1F, q931_uil1_vals,
+		      "Unknown (0x%02X)"));
+		offset += 1;
+		len -= 1;
+		
+		if (octet & Q931_IE_VL_EXTENSION)
+			goto l1_done;
+		if (len == 0)
+			return;
+		octet = pd[offset];
+		proto_tree_add_text(tree, offset, 1,
+		    "Layer 1 is %s",
+		    (octet & 0x40) ? "Asynchronous" : "Synchronous");
+		proto_tree_add_text(tree, offset, 1,
+		    "Layer 1 in-band negotiation is %spossible",
+		    (octet & 0x20) ? "" : "not ");
+		proto_tree_add_text(tree, offset, 1,
+		    "User rate: %s",
+		    val_to_str(octet & 0x1F, q931_l1_user_rate_vals,
+		      "Unknown (0x%02X)"));
+		offset += 1;
+		len -= 1;
+
+		if (octet & Q931_IE_VL_EXTENSION)
+			goto l1_done;
+		if (len == 0)
+			return;
+		octet = pd[offset];
+		proto_tree_add_text(tree, offset, 1,
+		    "Intermediate rate: %s",
+		      val_to_str(octet & 0x60, q931_l1_intermediate_rate_vals,
+		       "Unknown (0x%X)"));
+		proto_tree_add_text(tree, offset, 1,
+		    "%s to send data with network independent clock",
+		    (octet & 0x10) ? "Required" : "Not required");
+		proto_tree_add_text(tree, offset, 1,
+		    "%s accept data with network independent clock",
+		    (octet & 0x08) ? "Can" : "Cannot");
+		proto_tree_add_text(tree, offset, 1,
+		    "%s to send data with flow control mechanism",
+		    (octet & 0x04) ? "Required" : "Not required");
+		proto_tree_add_text(tree, offset, 1,
+		    "%s accept data with flow control mechanism",
+		    (octet & 0x02) ? "Can" : "Cannot");
+		offset += 1;
+		len -= 1;
+
+		if (octet & Q931_IE_VL_EXTENSION)
+			goto l1_done;
+		if (len == 0)
+			return;
+		octet = pd[offset];
+		proto_tree_add_text(tree, offset, 1,
+		    "Rate adaptation header %sincluded",
+		    (octet & 0x40) ? "" : "not ");
+		proto_tree_add_text(tree, offset, 1,
+		    "Multiple frame establishment %ssupported",
+		    (octet & 0x20) ? "" : "not ");
+		proto_tree_add_text(tree, offset, 1,
+		    "%s mode of operation",
+		    (octet & 0x10) ? "Protocol sensitive" : "Bit transparent");
+		proto_tree_add_text(tree, offset, 1,
+		    (octet & 0x08) ?
+		      "Full protocol negotiation" : "LLI = 256 only");
+		proto_tree_add_text(tree, offset, 1,
+		    "Message originator is %s",
+		    (octet & 0x04) ? "Assignor only" : "Default assignee");
+		proto_tree_add_text(tree, offset, 1,
+		    "Negotiation is done %s",
+		    (octet & 0x02) ? "in-band" : "out-of-band");
+		offset += 1;
+		len -= 1;
+
+		if (octet & Q931_IE_VL_EXTENSION)
+			goto l1_done;
+		if (len == 0)
+			return;
+		octet = pd[offset];
+		proto_tree_add_text(tree, offset, 1,
+		    "Stop bits: %s",
+		      val_to_str(octet & 0x60, q931_l1_stop_bits_vals,
+		       "Unknown (0x%X)"));
+		proto_tree_add_text(tree, offset, 1,
+		    "Data bits: %s",
+		      val_to_str(octet & 0x18, q931_l1_data_bits_vals,
+		       "Unknown (0x%X)"));
+		proto_tree_add_text(tree, offset, 1,
+		    "Parity: %s",
+		      val_to_str(octet & 0x08, q931_l1_parity_vals,
+		       "Unknown (0x%X)"));
+
+		if (octet & Q931_IE_VL_EXTENSION)
+			goto l1_done;
+		if (len == 0)
+			return;
+		octet = pd[offset];
+		proto_tree_add_text(tree, offset, 1,
+		    "%s duplex",
+		    (octet & 0x40) ? "Full" : "Half");
+		modem_type = octet & 0x3F;
+		if (modem_type <= 0x5 ||
+		    (modem_type >= 0x20 && modem_type <= 0x2F)) {
+			proto_tree_add_text(tree, offset, 1,
+			    "Modem type: National use 0x%02X", modem_type);
+		} else if (modem_type >= 0x30) {
+			proto_tree_add_text(tree, offset, 1,
+			    "Modem type: User specified 0x%02X", modem_type);
+		} else {
+			proto_tree_add_text(tree, offset, 1,
+			    "Modem type: %s",
+			      val_to_str(modem_type, q931_l1_modem_type_vals,
+			      NULL));
+		}
+		offset += 1;
+		len -= 1;
+	}
+l1_done:
+	;
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	if ((octet & 0x60) == 0x40) {
+		/*
+		 * Layer 2 information.
+		 */
+		uil2_protocol = octet & 0x1F;
+		proto_tree_add_text(tree, offset, 1,
+		    "User information layer 2 protocol: %s",
+		    val_to_str(uil2_protocol, q931_uil2_vals,
+		      "Unknown (0x%02X)"));
+		offset += 1;
+		len -= 1;
+
+		/*
+		 * XXX - only in Low-layer compatibility information element.
+		 */
+		if (octet & Q931_IE_VL_EXTENSION)
+			goto l2_done;
+		if (len == 0)
+			return;
+		octet = pd[offset];
+		proto_tree_add_text(tree, offset, 1,
+		    "Mode: %s",
+		    val_to_str(octet & 0x60, q931_mode_vals,
+		      "Unknown (0x%02X)"));
+		offset += 1;
+		len -= 1;
+
+		if (octet & Q931_IE_VL_EXTENSION)
+			goto l2_done;
+		if (len == 0)
+			return;
+		octet = pd[offset];
+		if (uil2_protocol == Q931_UIL2_USER_SPEC) {
+			proto_tree_add_text(tree, offset, 1,
+			    "User-specified layer 2 protocol information: 0x%02X",
+			    octet & 0x7F);
+		} else {
+			proto_tree_add_text(tree, offset, 1,
+			    "Window size: %u k", octet & 0x7F);
+		}
+		offset += 1;
+		len -= 1;
+	}
+l2_done:
+	;
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	if ((octet & 0x60) == 0x60) {
+		/*
+		 * Layer 3 information.
+		 */
+		uil3_protocol = octet & 0x1F;
+		proto_tree_add_text(tree, offset, 1,
+		    "User information layer 3 protocol: %s",
+		    val_to_str(uil3_protocol, q931_uil3_vals,
+		      "Unknown (0x%02X)"));
+		offset += 1;
+		len -= 1;
+
+
+		/*
+		 * XXX - only in Low-layer compatibility information element.
+		 */
+		if (octet & Q931_IE_VL_EXTENSION)
+			goto l3_done;
+		if (len == 0)
+			return;
+		octet = pd[offset];
+		switch (uil3_protocol) {
+
+		case Q931_UIL3_X25_PL:
+		case Q931_UIL3_ISO_8208:
+		case Q931_UIL3_X223:
+			proto_tree_add_text(tree, offset, 1,
+			    "Mode: %s",
+			    val_to_str(octet & 0x60, q931_mode_vals,
+			      "Unknown (0x%02X)"));
+
+			if (octet & Q931_IE_VL_EXTENSION)
+				goto l3_done;
+			if (len == 0)
+				return;
+			octet = pd[offset];
+			proto_tree_add_text(tree, offset, 1,
+			    "Default packet size: %u", octet & 0x0F);
+			offset += 1;
+			len -= 1;
+
+			if (octet & Q931_IE_VL_EXTENSION)
+				goto l3_done;
+			if (len == 0)
+				return;
+			octet = pd[offset];
+			proto_tree_add_text(tree, offset, 1,
+			    "Packet window size: %u", octet & 0x7F);
+			offset += 1;
+			len -= 1;
+			break;
+
+		case Q931_UIL3_USER_SPEC:
+			proto_tree_add_text(tree, offset, 1,
+			    "Default packet size: %u octets",
+			    1 << (octet & 0x0F));
+			offset += 1;
+			len -= 1;
+			break;
+		}
+	}
+l3_done:
+	;
+}
+
+/*
+ * Dissect a Cause information element.
+ */
+static const value_string q931_cause_coding_standard_vals[] = {
+	{ 0x00, "ITU standardized coding" },
+	{ 0x20, "ISO/IEC standard" },
+	{ 0x40, "National standard" },
+	{ 0x60, "Standard specific to identified location" },
+	{ 0,    NULL }
+};
+	
+static const value_string q931_cause_location_vals[] = {
+	{ 0x00, "User (U)" },
+	{ 0x01, "Private network serving the local user (LPN)" },
+	{ 0x02, "Public network serving the local user (LN)" },
+	{ 0x03, "Transit network (TN)" },
+	{ 0x04, "Public network serving the remote user (RLN)" },
+	{ 0x05, "Private network serving the remote user (RPN)" },
+	{ 0x07, "International network (INTL)" },
+	{ 0x0A, "Network beyond interworking point (BI)" },
+	{ 0,    NULL }
+};
+
+static const value_string q931_cause_recommendation_vals[] = {
+	{ 0x00, "Q.931" },
+	{ 0x03, "X.21" },
+	{ 0x04, "X.25" },
+	{ 0x05, "Q.1031/Q.1051" },
+	{ 0,    NULL }
+};
+
 /*
  * Cause codes for Cause.
  */
 static const value_string q931_cause_code_vals[] = {
-	{ 0,	"Valid cause code not yet received" },
-	{ 1,	"Unallocated (unassigned) number" },
-	{ 2,	"No route to specified transit network (WAN)" },
-	{ 3,	"No route to destination" },
-	{ 4,	"send special information tone" },
-	{ 5,	"Misdialled trunk prefix" },
-	{ 6,	"Channel unacceptable" },
-	{ 7,	"Call awarded and being delivered in an established channel" },
-	{ 8,	"Prefix 0 dialed but not allowed" },
-	{ 9,	"Prefix 1 dialed but not allowed" },
-	{ 10,	"Prefix 1 dialed but not required" },
-	{ 11,	"More digits received than allowed, call is proceeding" },
-	{ 16,	"Normal call clearing" },
-	{ 17,	"User busy" },
-	{ 18,	"No user responding" },
-	{ 19,	"No answer from user" },
-	{ 20,	"Subscriber absent" },
-	{ 21,	"Call rejected" },
-	{ 22,	"Number changed" },
-	{ 23,	"Reverse charging rejected" },
-	{ 24,	"Call suspended" },
-	{ 25,	"Call resumed" },
-	{ 26,	"Non-selected user clearing" },
-	{ 27,	"Destination out of order" },
-	{ 28,	"Invalid number format (incomplete number)" },
-	{ 29,	"Facility rejected" },
-	{ 30,	"Response to STATUS ENQUIRY" },
-	{ 31,	"Normal, unspecified" },
-	{ 33,	"Circuit out of order" },
-	{ 34,	"No circuit/channel available" },
-	{ 35,	"Destination unattainable" },
-	{ 37,	"Degraded service" },
-	{ 38,	"Network (WAN) out of order" },
-	{ 39,	"Transit delay range cannot be achieved" },
-	{ 40,	"Throughput range cannot be achieved" },
-	{ 41,	"Temporary failure" },
-	{ 42,	"Switching equipment congestion" },
-	{ 43,	"Access information discarded" },
-	{ 44,	"Requested circuit channel not available" },
-	{ 45,	"Pre-empted" },
-	{ 46,	"Precedence call blocked" },
-	{ 47,	"Resource unavailable - unspecified" },
-	{ 49,	"Quality of service unavailable" },
-	{ 50,	"Requested facility not subscribed" },
-	{ 51,	"Reverse charging not allowed" },
-	{ 52,	"Outgoing calls barred" },
-	{ 53,	"Outgoing calls barred within CUG" },
-	{ 54,	"Incoming calls barred" },
-	{ 55,	"Incoming calls barred within CUG" },
-	{ 56,	"Call waiting not subscribed" },
-	{ 57,	"Bearer capability not authorized" },
-	{ 58,	"Bearer capability not presently available" },
-	{ 62,	"Inconsistency in designated outgoing access information and subscriber class" },
-	{ 63,	"Service or option not available, unspecified" },
-	{ 65,	"Bearer service not implemented" },
-	{ 66,	"Channel type not implemented" },
-	{ 67,	"Transit network selection not implemented" },
-	{ 68,	"Message not implemented" },
-	{ 69,	"Requested facility not implemented" },
-	{ 70,	"Only restricted digital information bearer capability is available" },
-	{ 79,	"Service or option not implemented, unspecified" },
-	{ 81,	"Invalid call reference value" },
-	{ 82,	"Identified channel does not exist" },
-	{ 83,	"A suspended call exists, but this call identity does not" },
-	{ 84,	"Call identity in use" },
-	{ 85,	"No call suspended" },
-	{ 86,	"Call having the requested call identity has been cleared" },
-	{ 87,	"Called user not member of CUG" },
-	{ 88,	"Incompatible destination" },
-	{ 89,	"Non-existent abbreviated address entry" },
-	{ 90,	"Destination address missing, and direct call not subscribed" },
-	{ 91,	"Invalid transit network selection (national use)" },
-	{ 92,	"Invalid facility parameter" },
-	{ 93,	"Mandatory information element is missing" },
-	{ 95,	"Invalid message, unspecified" },
-	{ 96,	"Mandatory information element is missing" },
-	{ 97,	"Message type non-existent or not implemented" },
-	{ 98,	"Message not compatible with call state or message type non-existent or not implemented" },
-	{ 99,	"Information element nonexistant or not implemented" },
-	{ 100,	"Invalid information element contents" },
-	{ 101,	"Message not compatible with call state" },
-	{ 102,	"Recovery on timer expiry" },
-	{ 103,	"Parameter non-existent or not implemented - passed on" },
-	{ 110,	"Message with unrecognized parameter discarded" },
-	{ 111,	"Protocol error, unspecified" },
-	{ 127,	"Internetworking, unspecified" },
+	{ 0x00,	"Valid cause code not yet received" },
+	{ 0x01,	"Unallocated (unassigned) number" },
+	{ 0x02,	"No route to specified transit network" },
+	{ 0x03,	"No route to destination" },
+	{ 0x04,	"Send special information tone" },
+	{ 0x05,	"Misdialled trunk prefix" },
+	{ 0x06,	"Channel unacceptable" },
+	{ 0x07,	"Call awarded and being delivered in an established channel" },
+	{ 0x08,	"Prefix 0 dialed but not allowed" },
+	{ 0x09,	"Prefix 1 dialed but not allowed" },
+	{ 0x0A,	"Prefix 1 dialed but not required" },
+	{ 0x0B,	"More digits received than allowed, call is proceeding" },
+	{ 0x10,	"Normal call clearing" },
+	{ 0x11,	"User busy" },
+	{ 0x12,	"No user responding" },
+	{ 0x13,	"No answer from user (user alerted)" },
+	{ 0x14,	"Subscriber absent" },
+	{ 0x15,	"Call rejected" },
+	{ 0x16,	"Number changed" },
+	{ 0x17,	"Reverse charging rejected" },
+	{ 0x18,	"Call suspended" },
+	{ 0x19,	"Call resumed" },
+	{ 0x1A,	"Non-selected user clearing" },
+	{ 0x1B,	"Destination out of order" },
+	{ 0x1C,	"Invalid number format (incomplete number)" },
+	{ 0x1D,	"Facility rejected" },
+	{ 0x1E,	"Response to STATUS ENQUIRY" },
+	{ 0x1F,	"Normal unspecified" },
+	{ 0x21,	"Circuit out of order" },
+	{ 0x22,	"No circuit/channel available" },
+	{ 0x23,	"Destination unattainable" },
+	{ 0x25,	"Degraded service" },
+	{ 0x26,	"Network out of order" },
+	{ 0x27,	"Transit delay range cannot be achieved" },
+	{ 0x28,	"Throughput range cannot be achieved" },
+	{ 0x29,	"Temporary failure" },
+	{ 0x2A,	"Switching equipment congestion" },
+	{ 0x2B,	"Access information discarded" },
+	{ 0x2C,	"Requested circuit/channel not available" },
+	{ 0x2D,	"Pre-empted" },
+	{ 0x2E,	"Precedence call blocked" },
+	{ 0x2F,	"Resources unavailable, unspecified" },
+	{ 0x31,	"Quality of service unavailable" },
+	{ 0x32,	"Requested facility not subscribed" },
+	{ 0x33,	"Reverse charging not allowed" },
+	{ 0x34,	"Outgoing calls barred" },
+	{ 0x35,	"Outgoing calls barred within CUG" },
+	{ 0x36,	"Incoming calls barred" },
+	{ 0x37,	"Incoming calls barred within CUG" },
+	{ 0x38,	"Call waiting not subscribed" },
+	{ 0x39,	"Bearer capability not authorized" },
+	{ 0x3A,	"Bearer capability not presently available" },
+	{ 0x3E,	"Inconsistency in designated outgoing access information and subscriber class" },
+	{ 0x3F,	"Service or option not available, unspecified" },
+	{ 0x41,	"Bearer capability not implemented" },
+	{ 0x42,	"Channel type not implemented" },
+	{ 0x43,	"Transit network selection not implemented" },
+	{ 0x44,	"Message not implemented" },
+	{ 0x45,	"Requested facility not implemented" },
+	{ 0x46,	"Only restricted digital information bearer capability is available" },
+	{ 0x4F,	"Service or option not implemented, unspecified" },
+	{ 0x51,	"Invalid call reference value" },
+	{ 0x52,	"Identified channel does not exist" },
+	{ 0x53,	"Call identity does not exist for suspended call" },
+	{ 0x54,	"Call identity in use" },
+	{ 0x55,	"No call suspended" },
+	{ 0x56,	"Call having the requested call identity has been cleared" },
+	{ 0x57,	"Called user not member of CUG" },
+	{ 0x58,	"Incompatible destination" },
+	{ 0x59,	"Non-existent abbreviated address entry" },
+	{ 0x5A,	"Destination address missing, and direct call not subscribed" },
+	{ 0x5B,	"Invalid transit network selection (national use)" },
+	{ 0x5C,	"Invalid facility parameter" },
+	{ 0x5D,	"Mandatory information element is missing" },
+	{ 0x5F,	"Invalid message, unspecified" },
+	{ 0x60,	"Mandatory information element is missing" },
+	{ 0x61,	"Message type non-existent or not implemented" },
+	{ 0x62,	"Message not compatible with call state or message type non-existent or not implemented" },
+	{ 0x63,	"Information element nonexistant or not implemented" },
+	{ 0x64,	"Invalid information element contents" },
+	{ 0x65,	"Message not compatible with call state" },
+	{ 0x66,	"Recovery on timer expiry" },
+	{ 0x67,	"Parameter non-existent or not implemented - passed on" },
+	{ 0x6E,	"Message with unrecognized parameter discarded" },
+	{ 0x6F,	"Protocol error, unspecified" },
+	{ 0x7F,	"Internetworking, unspecified" },
 	{ 0,	NULL }
 };
 
+static void
+dissect_q931_cause_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	guint8 octet;
+	guint8 coding_standard;
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	coding_standard = octet & 0x60;
+	proto_tree_add_text(tree, offset, 1,
+	    "Coding standard: %s",
+	    val_to_str(coding_standard, q931_cause_coding_standard_vals, NULL));
+	if (coding_standard != Q931_ITU_STANDARDIZED_CODING) {
+		/*
+		 * We don't know how the cause is encoded,
+		 * so just dump it as data and be done with it.
+		 */
+		proto_tree_add_text(tree, offset,
+		    len, "Data: %s", bytes_to_str(&pd[offset], len));
+		return;
+	}
+	proto_tree_add_text(tree, offset, 1,
+	    "Location: %s",
+	    val_to_str(octet & 0x0F, q931_cause_location_vals,
+	      "Unknown (0x%X)"));
+	offset += 1;
+	len -= 1;
+
+	if (!(octet & Q931_IE_VL_EXTENSION)) {
+		if (len == 0)
+			return;
+		octet = pd[offset];
+		proto_tree_add_text(tree, offset, 1,
+		    "Recommendation: %s",
+		    val_to_str(octet & 0x7F, q931_cause_recommendation_vals,
+		      "Unknown (0x%X)"));
+		offset += 1;
+		len -= 1;
+	}
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	proto_tree_add_text(tree, offset, 1,
+	    "Cause value: %s",
+	    val_to_str(octet & 0x7F, q931_cause_code_vals,
+	      "Unknown (0x%X)"));
+	offset += 1;
+	len -= 1;
+
+	if (len == 0)
+		return;
+	proto_tree_add_text(tree, offset, 1,
+	    "Diagnostics: %s",
+	    bytes_to_str(&pd[offset], len));
+}
+
+/*
+ * Dissect a Call state information element.
+ */
+static const value_string q931_coding_standard_vals[] = {
+	{ 0x00, "ITU standardized coding" },
+	{ 0x20, "ISO/IEC standard" },
+	{ 0x40, "National standard" },
+	{ 0x60, "Standard defined for the network" },
+	{ 0,    NULL }
+};
+	
+static const value_string q931_call_state_vals[] = {
+	{ 0x00, "Null" },
+	{ 0x01, "Call initiated" },
+	{ 0x02, "Overlap sending" },
+	{ 0x03, "Outgoing call proceeding" },
+	{ 0x04, "Call delivered" },
+	{ 0x06, "Call present" },
+	{ 0x07, "Call received" },
+	{ 0x09, "Connect request" },
+	{ 0x0A, "Incoming call proceeding" },
+	{ 0x0B, "Active" },
+	{ 0x0C, "Disconnect request" },
+	{ 0x0F, "Disconnect indication" },
+	{ 0x11, "Suspend request" },
+	{ 0x13, "Resume request" },
+	{ 0x16, "Release request" },
+	{ 0x19, "Overlap receiving" },
+	{ 0x3D, "Restart request" },
+	{ 0x3E, "Restart" },
+	{ 0,    NULL }
+};
+
+static void
+dissect_q931_call_state_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	guint8 octet;
+	guint8 coding_standard;
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	coding_standard = octet & 0x60;
+	proto_tree_add_text(tree, offset, 1,
+	    "Coding standard: %s",
+	    val_to_str(coding_standard, q931_coding_standard_vals, NULL));
+	if (coding_standard != Q931_ITU_STANDARDIZED_CODING) {
+		/*
+		 * We don't know how the call state is encoded,
+		 * so just dump it as data and be done with it.
+		 */
+		proto_tree_add_text(tree, offset,
+		    len, "Data: %s", bytes_to_str(&pd[offset], len));
+		return;
+	}
+	proto_tree_add_text(tree, offset, 1,
+	    "Call state: %s",
+	    val_to_str(octet & 0x3F, q931_call_state_vals,
+	      "Unknown (0x%02X)"));
+}
+
+/*
+ * Dissect a Channel identification information element.
+ */
+#define	Q931_INTERFACE_IDENTIFIED	0x40
+#define	Q931_NOT_BASIC_CHANNEL		0x20
+
+static const value_string q931_basic_channel_selection_vals[] = {
+	{ 0x00, "No channel" },
+	{ 0x01, "B1 channel" },
+	{ 0x02, "B2 channel" },
+	{ 0x03, "Any channel" },
+	{ 0,    NULL }
+};
+
+#define	Q931_IS_SLOT_MAP		0x10
+	
+static const value_string q931_element_type_vals[] = {
+	{ 0x03, "B-channel units" },
+	{ 0x06, "H0-channel units" },
+	{ 0x08, "H11-channel units" },
+	{ 0x09, "H12-channel units" },
+	{ 0,    NULL }
+};
+
+static void
+dissect_q931_channel_identification_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	guint8 octet;
+	int identifier_offset;
+	int identifier_len;
+	guint8 coding_standard;
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	proto_tree_add_text(tree, offset, 1,
+	    "Interface %s identified",
+	    (octet & Q931_INTERFACE_IDENTIFIED) ? "explicitly" : "implicitly");
+	proto_tree_add_text(tree, offset, 1,
+	    "%s interface",
+	    (octet & Q931_NOT_BASIC_CHANNEL) ? "Not basic" : "Basic");
+	proto_tree_add_text(tree, offset, 1,
+	    "Indicated channel is %s",
+	    (octet & 0x08) ? "required" : "preferred");
+	proto_tree_add_text(tree, offset, 1,
+	    "Indicated channel is %sthe D-channel",
+	    (octet & 0x04) ? "" : "not ");
+	if (octet & Q931_NOT_BASIC_CHANNEL) {
+	} else {
+		proto_tree_add_text(tree, offset, 1,
+		    "Channel selection: %s",
+		    val_to_str(octet & 0x03, q931_basic_channel_selection_vals,
+		      NULL));
+	}
+	offset += 1;
+	len -= 1;
+
+	if (octet & Q931_INTERFACE_IDENTIFIED) {
+		identifier_offset = offset;
+		identifier_len = 0;
+		do {
+			if (len == 0)
+				break;
+			octet = pd[offset];
+			offset += 1;
+			len -= 1;
+			identifier_len++;
+		} while (!(octet & Q931_IE_VL_EXTENSION));
+
+		/*
+		 * XXX - do we want to strip off the 8th bit on the
+		 * last octet of the interface identifier?
+		 */
+		if (identifier_len != 0) {
+			proto_tree_add_text(tree, identifier_offset,
+			    identifier_len, "Interface identifier: %s",
+			    bytes_to_str(&pd[identifier_offset],
+			      identifier_len));
+		}
+	}
+
+	if (octet & Q931_NOT_BASIC_CHANNEL) {
+		if (len == 0)
+			return;
+		octet = pd[offset];
+		coding_standard = octet & 0x60;
+		proto_tree_add_text(tree, offset, 1,
+		    "Coding standard: %s",
+		    val_to_str(coding_standard, q931_coding_standard_vals,
+		      NULL));
+		if (coding_standard != Q931_ITU_STANDARDIZED_CODING) {
+			/*
+			 * We don't know how the channel identifier is
+			 * encoded, so just dump it as data and be done
+			 * with it.
+			 */
+			proto_tree_add_text(tree, offset,
+			    len, "Data: %s", bytes_to_str(&pd[offset], len));
+			return;
+		}
+		proto_tree_add_text(tree, offset, 1,
+		    "Channel is indicated by %s",
+		    (octet & Q931_IS_SLOT_MAP) ? "slot map" : "number");
+		proto_tree_add_text(tree, offset, 1,
+		    "%s type: %s",
+		    (octet & Q931_IS_SLOT_MAP) ? "Map element" : "Channel",
+		    val_to_str(octet & 0x0F, q931_element_type_vals,
+		    "Unknown (0x%02X)"));
+
+		/*
+		 * XXX - dump the channel number or slot map.
+		 */
+	}
+}
+
+/*
+ * Dissect a Progress indicator information element.
+ */
+static const value_string q931_progress_description_vals[] = {
+	{ 0x01, "Call is not end-to-end ISDN - progress information available in-band" },
+	{ 0x02, "Destination address is non-ISDN" },
+	{ 0x03, "Origination address is non-ISDN" },
+	{ 0x04, "Call has returned to the ISDN" },
+	{ 0x05, "Interworking has occurred and has resulted in a telecommunications service change" },
+	{ 0x08, "In-band information or an appropriate pattern is now available" },
+	{ 0,    NULL }
+};
+
+static void
+dissect_q931_progress_indicator_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	guint8 octet;
+	guint8 coding_standard;
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	coding_standard = octet & 0x60;
+	proto_tree_add_text(tree, offset, 1,
+	    "Coding standard: %s",
+	    val_to_str(coding_standard, q931_cause_coding_standard_vals, NULL));
+	if (coding_standard != Q931_ITU_STANDARDIZED_CODING) {
+		/*
+		 * We don't know how the progress indicator is encoded,
+		 * so just dump it as data and be done with it.
+		 */
+		proto_tree_add_text(tree, offset,
+		    len, "Data: %s", bytes_to_str(&pd[offset], len));
+		return;
+	}
+	proto_tree_add_text(tree, offset, 1,
+	    "Location: %s",
+	    val_to_str(octet & 0x0F, q931_cause_location_vals,
+	      "Unknown (0x%X)"));
+	offset += 1;
+	len -= 1;
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	proto_tree_add_text(tree, offset, 1,
+	    "Progress description: %s",
+	    val_to_str(octet & 0x7F, q931_progress_description_vals,
+	      "Unknown (0x%02X)"));
+}
+
+/*
+ * Dissect a Network-specific facilities information element.
+ */
+static const value_string q931_netid_type_vals[] = {
+	{ 0x00, "User specified" },
+	{ 0x20, "National network identification" },
+	{ 0x30, "International network identification" },
+	{ 0,    NULL }
+};
+
+static const value_string q931_netid_plan_vals[] = {
+	{ 0x00, "Unknown" },
+	{ 0x01, "Carrier Identification Code" },
+	{ 0x03, "X.121 data network identification code" },
+	{ 0,    NULL }
+};
+
+static void
+dissect_q931_ns_facilities_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	guint8 octet;
+	int netid_len;
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	netid_len = octet & 0x7F;
+	proto_tree_add_text(tree, offset, 1,
+	    "Network identification length: %u",
+	    netid_len);
+	offset += 1;
+	len -= 1;
+	if (netid_len != 0) {
+		if (len == 0)
+			return;
+		octet = pd[offset];
+		proto_tree_add_text(tree, offset, 1,
+		    "Progress description: %s",
+		    val_to_str(octet & 0x70, q931_netid_type_vals,
+		      "Unknown (0x%02X)"));
+		proto_tree_add_text(tree, offset, 1,
+		    "Network identification plan: %s",
+		    val_to_str(octet & 0x0F, q931_netid_plan_vals,
+		      "Unknown (0x%02X)"));
+		offset += 1;
+		len -= 1;
+		netid_len--;
+
+		if (len == 0)
+			return;
+		if (netid_len > len)
+			netid_len = len;
+		if (netid_len != 0) {
+			proto_tree_add_text(tree, offset, 1,
+			    "Network identification: %.*s",
+			    netid_len, &pd[offset]);
+			offset += netid_len;
+			len -= netid_len;
+		}
+	}
+
+	/*
+	 * Whatever is left is the network-specific facility
+	 * specification.
+	 */
+	 if (len == 0)
+	 	return;
+	proto_tree_add_text(tree, offset,
+	    len, "Network-specific facility specification: %s",
+	    bytes_to_str(&pd[offset], len));
+}
+
+/*
+ * Dissect a Notification indicator information element.
+ */
+static const value_string q931_notification_description_vals[] = {
+	{ 0x00, "User suspended" },
+	{ 0x01, "User resumed" },
+	{ 0x02, "Bearer service change" },
+	{ 0,    NULL }
+};
+
+static void
+dissect_q931_notification_indicator_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	guint8 octet;
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	proto_tree_add_text(tree, offset, 1,
+	    "Notification description: %s",
+	    val_to_str(octet & 0x7F, q931_notification_description_vals,
+	      "Unknown (0x%02X)"));
+}
+
+/*
+ * Dissect a Date/time information element.
+ */
+static void
+dissect_q931_date_time_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	if (len != 6) {
+		proto_tree_add_text(tree, offset, len,
+		    "Date/time: length is %d, should be 6\n", len);
+		return;
+	}
+	/*
+	 * XXX - what is "year" relative to?  Is "month" 0-origin or
+	 * 1-origin?
+	 */
+	proto_tree_add_text(tree, offset, 6,
+	    "Date/time: %u-%u-%u %u:%u:%u",
+	    pd[offset + 0], pd[offset + 1], pd[offset + 2],
+	    pd[offset + 3], pd[offset + 4], pd[offset + 5]);
+}
+
+/*
+ * Dissect a Signal information element.
+ */
+static const value_string q931_signal_vals[] = {
+	{ 0x00, "Dial tone on" },
+	{ 0x01, "Ring tone on" },
+	{ 0x02, "Intercept tone on" },
+	{ 0x03, "Network congestion tone on" },	/* "fast busy" */
+	{ 0x04, "Busy tone on" },
+	{ 0x05, "Confirm tone on" },
+	{ 0x06, "Answer tone on" },
+	{ 0x07, "Call waiting tone on" },
+	{ 0x08, "Off-hoke warning tone on" },
+	{ 0x09, "Preemption tone on" },
+	{ 0x3F, "Tones off" },
+	{ 0x40, "Alerting on - pattern 0" },
+	{ 0x41, "Alerting on - pattern 1" },
+	{ 0x42, "Alerting on - pattern 2" },
+	{ 0x43, "Alerting on - pattern 3" },
+	{ 0x44, "Alerting on - pattern 4" },
+	{ 0x45, "Alerting on - pattern 5" },
+	{ 0x46, "Alerting on - pattern 6" },
+	{ 0x47, "Alerting on - pattern 7" },
+	{ 0x4F, "Alerting off" },
+	{ 0,    NULL }
+};
+
+static void
+dissect_q931_signal_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	if (len != 1) {
+		proto_tree_add_text(tree, offset, len,
+		    "Signal: length is %d, should be 1\n", len);
+		return;
+	}
+	proto_tree_add_text(tree, offset, 1,
+	    "Signal: %s",
+	    val_to_str(pd[offset], q931_signal_vals, "Unknown (0x%02X)"));
+}
+
 /*
- * Call status tones for Signal.
+ * Dissect an Information rate information element.
  */
-#define	Q931_SIGNAL_DIAL_TONE		0x00
-#define	Q931_SIGNAL_RINGING		0x01
-#define	Q931_SIGNAL_INTERCEPT		0x02
-#define	Q931_SIGNAL_NETWORK_CONGESTION	0x03	/* "fast busy" */
-#define	Q931_SIGNAL_BUSY		0x04
-#define	Q931_SIGNAL_CONFIRM		0x05
-#define	Q931_SIGNAL_ANSWER		0x06
-#define	Q931_SIGNAL_CALL_WAITING	0x07
-#define	Q931_SIGNAL_OFF_HOOK_WARNING	0x08
-#define	Q931_SIGNAL_TONES_OFF		0x3F
+static const value_string q931_throughput_class_vals[] = {
+	{ 0x03, "75 bit/s" },
+	{ 0x04, "150 bit/s" },
+	{ 0x05, "300 bit/s" },
+	{ 0x06, "600 bit/s" },
+	{ 0x07, "1200 bit/s" },
+	{ 0x08, "2400 bit/s" },
+	{ 0x09, "4800 bit/s" },
+	{ 0x0A, "9600 bit/s" },
+	{ 0x0B, "19200 bit/s" },
+	{ 0x0C, "48000 bit/s" },
+	{ 0x0D, "64000 bit/s" },
+	{ 0,    NULL }
+};
+
+static void
+dissect_q931_information_rate_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	if (len != 4) {
+		proto_tree_add_text(tree, offset, len,
+		    "Information rate: length is %d, should be 4\n", len);
+		return;
+	}
+	proto_tree_add_text(tree, offset + 0, 1,
+	    "Incoming information rate: %s",
+	    val_to_str(pd[offset + 0] & 0x1F, q931_throughput_class_vals,
+	      "Unknown (0x%02X)"));
+	proto_tree_add_text(tree, offset + 1, 1,
+	    "Outgoing information rate: %s",
+	    val_to_str(pd[offset + 1] & 0x1F, q931_throughput_class_vals,
+	      "Unknown (0x%02X)"));
+	proto_tree_add_text(tree, offset + 2, 1,
+	    "Minimum incoming information rate: %s",
+	    val_to_str(pd[offset + 2] & 0x1F, q931_throughput_class_vals,
+	      "Unknown (0x%02X)"));
+	proto_tree_add_text(tree, offset + 3, 1,
+	    "Minimum outgoing information rate: %s",
+	    val_to_str(pd[offset + 3] & 0x1F, q931_throughput_class_vals,
+	      "Unknown (0x%02X)"));
+}
+
+static int
+dissect_q931_guint16_value(const u_char *pd, int offset, int len,
+    proto_tree *tree, char *label)
+{
+	guint8 octet;
+	guint16 value;
+	int value_len;
+
+	value_len = 0;
+
+	octet = pd[offset];
+	if (octet & Q931_IE_VL_EXTENSION) {
+		/*
+		 * Only one octet long - error.
+		 */
+		goto bad_length;
+	}
+	value = (octet & 0x3) << 14;
+	offset += 1;
+	len -= 1;
+	value_len++;
+
+	if (len == 0) {
+		/*
+		 * We've reached the end of the information element - error.
+		 */
+		goto past_end;
+	}
+	octet = pd[offset];
+	if (octet & Q931_IE_VL_EXTENSION) {
+		/*
+		 * Only two octets long - error.
+		 */
+		goto bad_length;
+	}
+	value |= (octet & 0x7F) << 7;
+	offset += 1;
+	len -= 1;
+	value_len++;
+
+	if (len == 0) {
+		/*
+		 * We've reached the end of the information element - error.
+		 */
+		goto past_end;
+	}
+	octet = pd[offset];
+	if (!(octet & Q931_IE_VL_EXTENSION)) {
+		/*
+		 * More than three octets long - error.
+		 */
+		goto bad_length;
+	}
+	value |= (octet & 0x7F);
+	offset += 1;
+	len -= 1;
+	value_len++;
+
+	proto_tree_add_text(tree, offset, value_len, "%s: %u ms", label,
+	    value);
+	return value_len;
+
+past_end:
+	proto_tree_add_text(tree, offset, len,
+	    "%s goes past end of information element", label);
+	return -1;
+
+bad_length:
+	proto_tree_add_text(tree, offset, len, "%s isn't 3 octets long",
+	    label);
+	return -1;
+}
+
+/*
+ * Dissect an End-to-end transit delay information element.
+ */
+static void
+dissect_q931_e2e_transit_delay_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	int value_len;
+
+	if (len == 0)
+		return;
+	value_len = dissect_q931_guint16_value(pd, offset, len, tree,
+	    "Cumulative transit delay");
+	if (value_len < 0)
+		return;	/* error */
+	offset += value_len;
+	len -= value_len;
+
+	if (len == 0)
+		return;
+	value_len = dissect_q931_guint16_value(pd, offset, len, tree,
+	    "Requested end-to-end transit delay");
+	if (value_len < 0)
+		return;	/* error */
+	offset += value_len;
+	len -= value_len;
+
+	if (len == 0)
+		return;
+	value_len = dissect_q931_guint16_value(pd, offset, len, tree,
+	    "Maximum end-to-end transit delay");
+}
+
+/*
+ * Dissect a Transit delay selection and indication information element.
+ */
+static void
+dissect_q931_td_selection_and_int_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	if (len == 0)
+		return;
+	dissect_q931_guint16_value(pd, offset, len, tree,
+	    "Transit delay");
+}
+
+/*
+ * Dissect a Packet layer window size information element.
+ */
+static void
+dissect_q931_pl_window_size_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	if (len == 0)
+		return;
+	proto_tree_add_text(tree, offset, 1,
+	    "Forward value: %u", pd[offset] & 0x7F);
+	offset += 1;
+	len -= 1;
+
+	if (len == 0)
+		return;
+	proto_tree_add_text(tree, offset, 1,
+	    "Backward value: %u", pd[offset] & 0x7F);
+}
+
+/*
+ * Dissect a Packet layer size information element.
+ */
+static void
+dissect_q931_pl_size_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	if (len == 0)
+		return;
+	proto_tree_add_text(tree, offset, 1,
+	    "Forward value: %u", pd[offset] & 0x7F);
+	offset += 1;
+	len -= 1;
+
+	if (len == 0)
+		return;
+	proto_tree_add_text(tree, offset, 1,
+	    "Backward value: %u", pd[offset] & 0x7F);
+}
+
+/*
+ * Dissect a Closed user group information element.
+ */
+static const value_string q931_cug_indication_vals[] = {
+	{ 0x01, "Closed user group selection" },
+	{ 0x02, "Closed user group with outgoing access selection and indication" },
+	{ 0,    NULL }
+};
+
+static void
+dissect_q931_cug_ie(const u_char *pd, int offset, int len, proto_tree *tree)
+{
+	if (len == 0)
+		return;
+	proto_tree_add_text(tree, offset, 1,
+	    "CUG indication: %s",
+	    val_to_str(pd[offset] & 0x07, q931_cug_indication_vals,
+	      "Unknown (0x%02X)"));
+	offset += 1;
+	len -= 1;
+
+	if (len == 0)
+		return;
+	proto_tree_add_text(tree, offset, len, "CUG index code: %.*s", len,
+	    &pd[offset]);
+}
+
+/*
+ * Dissect a Reverse charging indication information element.
+ */
+static const value_string q931_reverse_charging_indication_vals[] = {
+	{ 0x01, "Reverse charging requested" },
+	{ 0,    NULL }
+};
+
+static void
+dissect_q931_reverse_charge_ind_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	if (len == 0)
+		return;
+	proto_tree_add_text(tree, offset, 1,
+	    "Reverse charging indication: %s",
+	    val_to_str(pd[offset] & 0x07, q931_reverse_charging_indication_vals,
+	      "Unknown (0x%02X)"));
+}
+
+/*
+ * Dissect a (phone) number information element.
+ */
+static const value_string q931_number_type_vals[] = {
+	{ 0x00, "Unknown" },
+	{ 0x10, "International number" },
+	{ 0x20, "National number" },
+	{ 0x30, "Network specific number" },
+	{ 0x40, "Subscriber number" },
+	{ 0x60, "Abbreviated number" },
+	{ 0,    NULL }
+};
+
+static const value_string q931_numbering_plan_vals[] = {
+	{ 0x00, "Unknown" },
+	{ 0x01, "E.164 ISDN/telephony numbering" },
+	{ 0x03, "X.121 data numbering" },
+	{ 0x04, "F.69 Telex numbering" },
+	{ 0x08, "National standard numbering" },
+	{ 0x09, "Private numbering" },
+	{ 0,    NULL }
+};
+
+static const value_string q931_presentation_indicator_vals[] = {
+	{ 0x00, "Presentation allowed" },
+	{ 0x20, "Presentation restricted" },
+	{ 0x40, "Number not available due to interworking" },
+	{ 0,    NULL }
+};
+
+static const value_string q931_screening_indicator_vals[] = {
+	{ 0x00, "User-provided, not screened" },
+	{ 0x01, "User-provided, verified and passed" },
+	{ 0x02, "User-provided, verified and failed" },
+	{ 0x03, "Network-provided" },
+	{ 0,    NULL }
+};
+
+static const value_string q931_redirection_reason_vals[] = {
+	{ 0x00, "Unknown" },
+	{ 0x01, "Call forwarding busy or called DTE busy" },
+	{ 0x02, "Call forwarding no reply" },
+	{ 0x04, "Call deflection" },
+	{ 0x09, "Called DTE out of order" },
+	{ 0x0A, "Call forwarding by the called DTE" },
+	{ 0x0F, "Call forwarding unconditional or systematic call redirection" },
+	{ 0,    NULL }
+};
+
+static void
+dissect_q931_number_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	guint8 octet;
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	proto_tree_add_text(tree, offset, 1,
+	    "Type of number: %s",
+	    val_to_str(octet & 0x70, q931_number_type_vals,
+	      "Unknown (0x%02X)"));
+	proto_tree_add_text(tree, offset, 1,
+	    "Numbering plan: %s",
+	    val_to_str(octet & 0x0F, q931_numbering_plan_vals,
+	      "Unknown (0x%02X)"));
+	offset += 1;
+	len -= 1;
+
+	if (!(octet & Q931_IE_VL_EXTENSION)) {
+		if (len == 0)
+			return;
+		octet = pd[offset];
+		proto_tree_add_text(tree, offset, 1,
+		    "Presentation indicator: %s",
+		    val_to_str(octet & 0x60, q931_presentation_indicator_vals,
+		      "Unknown (0x%X)"));
+		proto_tree_add_text(tree, offset, 1,
+		    "Screening indicator: %s",
+		    val_to_str(octet & 0x03, q931_screening_indicator_vals,
+		      "Unknown (0x%X)"));
+		offset += 1;
+		len -= 1;
+	}
+
+	/*
+	 * XXX - only in a Redirecting number information element.
+	 */
+	if (!(octet & Q931_IE_VL_EXTENSION)) {
+		if (len == 0)
+			return;
+		octet = pd[offset];
+		proto_tree_add_text(tree, offset, 1,
+		    "Reason for redirection: %s",
+		    val_to_str(octet & 0x0F, q931_redirection_reason_vals,
+		      "Unknown (0x%X)"));
+		offset += 1;
+		len -= 1;
+	}
+
+	if (len == 0)
+		return;
+	proto_tree_add_text(tree, offset, len, "Number: %.*s",
+	    len, &pd[offset]);
+}
+
+/*
+ * Dissect a party subaddress information element.
+ */
+static const value_string q931_subaddress_type_vals[] = {
+	{ 0x00, "X.213[23]/ISO 8348 AD2 NSAP" },
+	{ 0x20, "User-specified" },
+	{ 0,    NULL }
+};
+
+static const value_string q931_odd_even_indicator_vals[] = {
+	{ 0x00, "Even number of address signals" },
+	{ 0x10, "Odd number of address signals" },
+	{ 0,    NULL }
+};
+
+static void
+dissect_q931_party_subaddr_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	guint8 octet;
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	proto_tree_add_text(tree, offset, 1,
+	    "Type of subaddress: %s",
+	    val_to_str(octet & 0x70, q931_subaddress_type_vals,
+	      "Unknown (0x%02X)"));
+	proto_tree_add_text(tree, offset, 1,
+	    "Odd/even indicator: %s",
+	    val_to_str(octet & 0x10, q931_odd_even_indicator_vals,
+	      NULL));
+	offset += 1;
+	len -= 1;
+
+	if (len == 0)
+		return;
+	proto_tree_add_text(tree, offset, len, "Subaddress: %s",
+	    bytes_to_str(&pd[offset], len));
+}
+
+/*
+ * Dissect a Restart indicator information element.
+ */
+static const value_string q931_restart_indicator_class_vals[] = {
+	{ 0x00, "Indicated channels" },
+	{ 0x06, "Single interface" },
+	{ 0x07, "All interfaces" },
+	{ 0,    NULL }
+};
+
+static void
+dissect_q931_restart_indicator_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	if (len != 1) {
+		proto_tree_add_text(tree, offset, len,
+		    "Restart indicator: length is %d, should be 1\n", len);
+		return;
+	}
+	proto_tree_add_text(tree, offset, 1,
+	    "Restart indicator: %s",
+	    val_to_str(pd[offset] & 0x07, q931_restart_indicator_class_vals,
+	      "Unknown (0x%02X)"));
+}
+
+/*
+ * Dissect a High-layer compatibility information element.
+ */
+static const value_string q931_high_layer_characteristics_vals[] = {
+	{ 0x01, "Telephony" },
+	{ 0x04, "F.182 Facsimile Group 2/3" },
+	{ 0x21, "F.184 Facsimile Group 4 Class I" },
+	{ 0x24, "F.230 Teletex, basic and mixed mode, and F.184 Facsimile Group 4, Classes II and III" },
+	{ 0x28, "F.220 Teletex, basic and processable mode" },
+	{ 0x31, "F.200 Teletex, basic mode" },
+	{ 0x32, "F.300 and T.102 syntax-based Videotex" },
+	{ 0x33, "F.300 and T.101 international Videotex interworking" },
+	{ 0x35, "F.60 Telex" },
+	{ 0x38, "X.400 Message Handling Systems" },
+	{ 0x41, "X.200 OSI application" },
+	{ 0x5E, "Reserved for maintenance" },
+	{ 0x5F, "Reserved for management" },
+	{ 0x60, "F.721 Audiovisual" },
+	{ 0,    NULL }
+};
+
+static void
+dissect_q931_high_layer_compat_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	guint8 octet;
+	guint8 coding_standard;
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	coding_standard = octet & 0x60;
+	proto_tree_add_text(tree, offset, 1,
+	    "Coding standard: %s",
+	    val_to_str(coding_standard, q931_coding_standard_vals, NULL));
+	if (coding_standard != Q931_ITU_STANDARDIZED_CODING) {
+		/*
+		 * We don't know how the call state is encoded,
+		 * so just dump it as data and be done with it.
+		 */
+		proto_tree_add_text(tree, offset,
+		    len, "Data: %s", bytes_to_str(&pd[offset], len));
+		return;
+	}
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	proto_tree_add_text(tree, offset, 1,
+	    "High layer characteristics identification: %s",
+	    val_to_str(octet & 0x7F, q931_high_layer_characteristics_vals,
+	      NULL));
+	offset += 1;
+	len -= 1;
+
+	if (!(octet & Q931_IE_VL_EXTENSION)) {
+		if (len == 0)
+			return;
+		octet = pd[offset];
+		proto_tree_add_text(tree, offset, 1,
+		    "Extended high layer characteristics identification: %s",
+		    val_to_str(octet & 0x7F, q931_high_layer_characteristics_vals,
+		      NULL));
+	}
+}
+
+
+/*
+ * Dissect a User-user information element.
+ */
+#define	Q931_PROTOCOL_DISCRIMINATOR_IA5	0x04
+
+static const value_string q931_protocol_discriminator_vals[] = {
+	{ 0x00,					"User-specific protocol" },
+	{ 0x01,					"OSI high layer protocols" },
+	{ 0x02,					"X.244" },
+	{ Q931_PROTOCOL_DISCRIMINATOR_IA5,	"IA5 characters" },
+	{ 0x05,					"X.208 and X.209 coded user information" },
+	{ 0x07,					"V.120 rate adaptation" },
+	{ 0x08,					"Q.931/I.451 user-network call control messages" },
+	{ 0,					NULL }
+};
+
+static void
+dissect_q931_user_user_ie(const u_char *pd, int offset, int len,
+    proto_tree *tree)
+{
+	guint8 octet;
+
+	if (len == 0)
+		return;
+	octet = pd[offset];
+	proto_tree_add_text(tree, offset, 1,
+	    "Protocol discriminator: %s",
+	    val_to_str(octet, q931_protocol_discriminator_vals,
+	    "Unknown (0x%02x)"));
+	offset += 1;
+	len -= 1;
+
+	if (len == 0)
+		return;
+	switch (octet) {
+
+	case Q931_PROTOCOL_DISCRIMINATOR_IA5:
+		proto_tree_add_text(tree, offset, len, "User information: %.*s",
+		    len, &pd[offset]);
+		break;
+
+	default:
+		proto_tree_add_text(tree, offset, len, "User information: %s",
+		    bytes_to_str(&pd[offset], len));
+		break;
+	}
+}
+
+/*
+ * Dissect information elements consisting of ASCII^H^H^H^H^HIA5 text.
+ */
+static void
+dissect_q931_ia5_ie(const u_char *pd, int offset, int len, proto_tree *tree,
+    char *label)
+{
+	if (len != 0) {
+		proto_tree_add_text(tree, offset, len, "%s: %.*s", label, len,
+		    &pd[offset]);
+	}
+}
 
 void
 dissect_q931(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
@@ -393,6 +1951,8 @@ dissect_q931(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
 	guint8		message_type;
 	guint8		info_element;
 	guint8		info_element_len;
+	int		codeset;
+	int		non_locking_shift;
 
 	if (check_col(fd, COL_PROTOCOL))
 		col_add_str(fd, COL_PROTOCOL, "Q.931");
@@ -428,17 +1988,28 @@ dissect_q931(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
 	/*
 	 * And now for the information elements....
 	 */
+	codeset = 0;	/* start out in codeset 0 */
+	non_locking_shift = TRUE;
 	while (IS_DATA_IN_FRAME(offset)) {
 		info_element = pd[offset];
+
+		/*
+		 * Check for the single-octet IEs.
+		 */
 		switch (info_element & Q931_IE_SO_IDENTIFIER_MASK) {
 
 		case Q931_IE_SHIFT:
+			non_locking_shift =
+			    !(info_element & Q931_IE_SHIFT_LOCKING);
+			codeset = info_element & Q931_IE_SHIFT_CODESET;
 			if (q931_tree != NULL) {
 				proto_tree_add_text(q931_tree, offset, 1,
-				    "Shift: %u", info_element & Q931_IE_SO_IE_MASK);
+				    "%s shift to codeset %u",
+				    (non_locking_shift ? "Non-locking" : "Locking"),
+				    codeset);
 			}
-			offset += 1;		
-			break;
+			offset += 1;
+			continue;
 
 		case Q931_IE_MORE_DATA_OR_SEND_COMP:
 			switch (info_element) {
@@ -465,59 +2036,201 @@ dissect_q931(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
 				}
 				break;
 			}
-			offset += 1;		
-			break;
+			offset += 1;
+			if (non_locking_shift)
+				codeset = 0;
+			continue;
 
 		case Q931_IE_CONGESTION_LEVEL:
 			if (q931_tree != NULL) {
 				proto_tree_add_text(q931_tree, offset, 1,
-				    "Congestion level: %u", info_element & Q931_IE_SO_IE_MASK);
+				    "Congestion level: %s",
+				    val_to_str(info_element & Q931_IE_SO_IE_MASK,
+				      q931_congestion_level_vals,
+				      "Unknown (0x%X)"));
 			}		
-			offset += 1;		
-			break;
+			offset += 1;
+			if (non_locking_shift)
+				codeset = 0;
+			continue;
 
 		case Q931_IE_REPEAT_INDICATOR:
 			if (q931_tree != NULL) {
 				proto_tree_add_text(q931_tree, offset, 1,
-				    "Repeat indicator: %u", info_element & Q931_IE_SO_IE_MASK);
+				    "Repeat indicator: %s",
+				    val_to_str(info_element & Q931_IE_SO_IE_MASK,
+				      q931_repeat_indication_vals,
+				      "Unknown (0x%X)"));
 			}		
-			offset += 1;		
-			break;
+			offset += 1;
+			if (non_locking_shift)
+				codeset = 0;
+			continue;
 
 		default:
-			/*
-			 * Variable-length IE.
-			 */
-			if (!BYTES_ARE_IN_FRAME(offset + 1, 1))
-				break;	/* ran past end of frame */
-			info_element_len = pd[offset + 1];
-			if (!BYTES_ARE_IN_FRAME(offset + 2, info_element_len))
-				break;	/* ran past end of frame */
-			if (q931_tree != NULL) {
-				ti = proto_tree_add_text(q931_tree, offset,
-				    1+1+info_element_len,
-				    "%s",
-				    val_to_str(info_element,
-				      q931_info_element_vals,
-				      "Unknown information element (0x%02X)"));
-				ie_tree = proto_item_add_subtree(ti,
-				    ETT_Q931_IE);
-				proto_tree_add_text(ie_tree, offset, 1,
-				    "Information element: %s",
-				    val_to_str(info_element,
-				      q931_info_element_vals,
-				      "Unknown"));
-				proto_tree_add_text(ie_tree, offset + 1, 1,
-				    "Length: %u", info_element_len);
+			break;
+		}
+
+		/*
+		 * Variable-length IE.
+		 */
+		if (!BYTES_ARE_IN_FRAME(offset + 1, 1))
+			break;	/* ran past end of frame */
+		info_element_len = pd[offset + 1];
+		if (!BYTES_ARE_IN_FRAME(offset + 2, info_element_len))
+			break;	/* ran past end of frame */
+		if (q931_tree != NULL) {
+			ti = proto_tree_add_text(q931_tree, offset,
+			    1+1+info_element_len, "%s",
+			    val_to_str(info_element, q931_info_element_vals,
+			      "Unknown information element (0x%02X)"));
+			ie_tree = proto_item_add_subtree(ti, ETT_Q931_IE);
+			proto_tree_add_text(ie_tree, offset, 1,
+			    "Information element: %s",
+			    val_to_str(info_element, q931_info_element_vals,
+			      "Unknown"));
+			proto_tree_add_text(ie_tree, offset + 1, 1,
+			    "Length: %u", info_element_len);
+
+			switch (info_element) {
+
+			case Q931_IE_SEGMENTED_MESSAGE:
+				dissect_q931_segmented_message_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_BEARER_CAPABILITY:
+			case Q931_IE_LOW_LAYER_COMPAT:
+				dissect_q931_bearer_capability_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_CAUSE:
+				dissect_q931_cause_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_CALL_STATE:
+				dissect_q931_call_state_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_CHANNEL_IDENTIFICATION:
+				dissect_q931_channel_identification_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_PROGRESS_INDICATOR:
+				dissect_q931_progress_indicator_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_NETWORK_SPECIFIC_FACIL:
+				dissect_q931_ns_facilities_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_NOTIFICATION_INDICATOR:
+				dissect_q931_notification_indicator_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_DISPLAY:
+				dissect_q931_ia5_ie(pd, offset + 2,
+				    info_element_len, ie_tree,
+				    "Display information");
+				break;
+
+			case Q931_IE_DATE_TIME:
+				dissect_q931_date_time_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_KEYPAD_FACILITY:
+				dissect_q931_ia5_ie(pd, offset + 2,
+				    info_element_len, ie_tree,
+				    "Keypad facility");
+				break;
+
+			case Q931_IE_SIGNAL:
+				dissect_q931_signal_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_INFORMATION_RATE:
+				dissect_q931_information_rate_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_E2E_TRANSIT_DELAY:
+				dissect_q931_e2e_transit_delay_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_TD_SELECTION_AND_INT:
+				dissect_q931_td_selection_and_int_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_PL_WINDOW_SIZE:
+				dissect_q931_pl_window_size_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_PL_SIZE:
+				dissect_q931_pl_size_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_CUG:
+				dissect_q931_cug_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_REVERSE_CHARGE_IND:
+				dissect_q931_reverse_charge_ind_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_CALLING_PARTY_NUMBER:
+			case Q931_IE_CALLED_PARTY_NUMBER:
+			case Q931_IE_REDIRECTING_NUMBER:
+				dissect_q931_number_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_CALLING_PARTY_SUBADDR:
+			case Q931_IE_CALLED_PARTY_SUBADDR:
+				dissect_q931_party_subaddr_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_RESTART_INDICATOR:
+				dissect_q931_restart_indicator_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_HIGH_LAYER_COMPAT:
+				dissect_q931_high_layer_compat_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			case Q931_IE_USER_USER:
+				dissect_q931_user_user_ie(pd,
+				    offset + 2, info_element_len, ie_tree);
+				break;
+
+			default:
 				proto_tree_add_text(ie_tree, offset + 2,
-				    info_element_len,
-				    "Data: %s",
+				    info_element_len, "Data: %s",
 				    bytes_to_str(&pd[offset + 2],
 				      info_element_len));
+				break;
 			}
-			offset += 1 + 1 + info_element_len;
-			break;
 		}
+		offset += 1 + 1 + info_element_len;
+		if (non_locking_shift)
+			codeset = 0;
 	}
 }