Add revk's SMS application (bug #1437). Thanks!

git-svn-id: http://svn.digium.com/svn/asterisk/trunk@2805 f38db490-d61c-443f-a65b-d21fe96a405b

3 files changed, 1364 insertions, 1 deletions

diff --git a/apps/Makefile b/apps/Makefile
index 6973ba29a..35e58f92f 100755
--- a/apps/Makefile
+++ b/apps/Makefile
@@ -26,7 +26,7 @@ APPS=app_dial.so app_playback.so app_voicemail.so app_directory.so app_mp3.so\
      app_enumlookup.so app_transfer.so app_setcidnum.so app_cdr.so \
      app_hasnewvoicemail.so app_sayunixtime.so app_cut.so app_read.so \
      app_setcdruserfield.so app_random.so app_ices.so app_eval.so \
-     app_nbscat.so app_sendtext.so app_exec.so
+     app_nbscat.so app_sendtext.so app_exec.so app_sms.so
 
 ifneq (${OSARCH},Darwin)
 APPS+=app_intercom.so
diff --git a/apps/app_sms.c b/apps/app_sms.c
new file mode 100755
index 000000000..8b6d0cb44
--- /dev/null
+++ b/apps/app_sms.c
@@ -0,0 +1,1227 @@
+/*
+ * Asterisk -- A telephony toolkit for Linux.
+ *
+ * SMS application - ETSI ES 201 912 protocol 1 implimentation
+ * 
+ * Copyright (C) 2004, Adrian Kennard, rights assigned to Digium
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License
+ */
+
+#include <asterisk/lock.h>
+#include <asterisk/file.h>
+#include <asterisk/logger.h>
+#include <asterisk/options.h>
+#include <asterisk/channel.h>
+#include <asterisk/pbx.h>
+#include <asterisk/module.h>
+#include <asterisk/callerid.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <ctype.h>
+
+#include <pthread.h>
+
+/* ToDo */
+/* When acting as SC and answering, should check for messages and send instead of sending EST as first packet */
+/* Add full VP support */
+/* Handle status report messages (generation and reception) */
+/* Log to show oa and da with no spaces to allow parsing */
+/* USC2 coding */
+
+static unsigned char message_ref;	/* arbitary message ref */
+
+static char *tdesc = "SMS/PSTN handler";
+
+static char *app = "SMS";
+
+static char *synopsis = "Communicates with SMS service centres and SMS capable analogue phones";
+
+static char *descrip =
+  "  SMS(name|[a][s]):  SMS handles exchange of SMS data with a call to/from SMS capabale\n"
+  "phone or SMS PSTN service centre. Can send and/or receive SMS messages.\n"
+  "Returns 0 if call handled correctly, or -1 if there were any problems.\n"
+  "Works to ETSI ES 201 912 compatible with BT SMS PSTN service in UK\n"
+  "Typical usage is to use to handle called from the SMS service centre CLI,\n"
+  "or to set up a call using 'outgoing' or manager interface to connect service centre to SMS()\n"
+  "name is the name of the queue used in /var/spool/asterisk/sms\n"
+  "Argument 'a' means answer, i.e. send initial FSK packet.\n"
+  "Argument 's' means act as service centre talking to a phone.\n"
+  "Messages are processed as per text file message queues.\n"
+  "Can also call as SMS(name|[s]|number|message) to queue a message.\n";
+
+static signed short wave[] =
+  { 0, 392, 782, 1167, 1545, 1913, 2270, 2612, 2939, 3247, 3536, 3802, 4045, 4263, 4455, 4619, 4755, 4862, 4938, 4985,
+  5000, 4985, 4938, 4862, 4755, 4619, 4455, 4263, 4045, 3802, 3536, 3247, 2939, 2612, 2270, 1913, 1545, 1167, 782, 392,
+  0, -392, -782, -1167,
+  -1545, -1913, -2270, -2612, -2939, -3247, -3536, -3802, -4045, -4263, -4455, -4619, -4755, -4862, -4938, -4985, -5000,
+  -4985, -4938, -4862,
+  -4755, -4619, -4455, -4263, -4045, -3802, -3536, -3247, -2939, -2612, -2270, -1913, -1545, -1167, -782, -392
+};
+
+STANDARD_LOCAL_USER;
+
+LOCAL_USER_DECL;
+
+/* SMS 7 bit character mapping */
+/* Note that some greek characters are simply coded as 191 (inverted question mark) as ISO-8859-1 does not do greek */
+/* Note 27 (escape) is to be displayed as a space as per GSM 03.38 */
+static unsigned char sms7to8[] = {
+  '@', 163, '$', 165, 232, 233, 249, 236, 242, 199, 10, 216, 248, 13, 197, 229,
+  191, '_', 191, 191, 191, 191, 191, 191, 191, 191, 191, ' ', 198, 230, 223, 201,
+  ' ', '!', '"', '#', 164, '%', '&', 39, '(', ')', '*', '+', ',', '-', '.', '/',
+  '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', ':', ';', '<', '=', '>', '?',
+  161, 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',
+  'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 196, 214, 209, 220, 167,
+  191, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
+  'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 228, 246, 241, 252, 224,
+};
+unsigned char sms8to7[256];
+
+typedef struct sms_s
+{
+  unsigned char hangup;		/* we are done... */
+  unsigned char smsc;		/* we are SMSC */
+  char queue[30];		/* queue name */
+  char oa[20];			/* originating address */
+  char da[20];			/* destination address */
+  time_t scts;			/* time stamp */
+  unsigned char pid;		/* protocol ID */
+  unsigned char dcs;		/* data coding scheme */
+  unsigned char mr;		/* message reference */
+  unsigned char udl;		/* user date length */
+  unsigned char srr:1;		/* Status Report request */
+  unsigned char rp:1;		/* Reply Path */
+  unsigned int vp;		/* validity period in minutes, 0 for not set */
+  unsigned char ud[160];	/* user data (message) */
+  unsigned char cli[20];	/* caller ID */
+  unsigned char ophase;		/* phase (0-79) for 0 and 1 frequencies (1300Hz and 2100Hz) */
+  unsigned char ophasep;	/* phase (0-79) for 1200 bps */
+  unsigned char obyte;		/* byte being sent */
+  unsigned int opause;		/* silent pause before sending (in sample periods) */
+  unsigned char obitp;		/* bit in byte */
+  unsigned char osync;		/* sync bits to send */
+  unsigned char obytep;		/* byte in data */
+  unsigned char obyten;		/* bytes in data */
+  unsigned char omsg[256];	/* data buffer (out) */
+  unsigned char imsg[200];	/* data buffer (in) */
+  signed long long ims0, imc0, ims1, imc1;	/* magnitude averages sin/cos 0/1 */
+  unsigned int idle;
+  unsigned short imag;		/* signal level */
+  unsigned char ips0, ips1, ipc0, ipc1;	/* phase sin/cos 0/1 */
+  unsigned char ibitl;		/* last bit */
+  unsigned char ibitc;		/* bit run length count */
+  unsigned char iphasep;	/* bit phase (0-79) for 1200 bps */
+  unsigned char ibitn;		/* bit number in byte being received */
+  unsigned char ibytev;		/* byte value being received */
+  unsigned char ibytep;		/* byte pointer in messafe */
+  unsigned char ibytec;		/* byte checksum for message */
+  unsigned char ierr;		/* error flag */
+  unsigned char ibith;		/* history of last bits */
+  unsigned char ibitt;		/* total of 1's in last 3 bites */
+  /* more to go here */
+} sms_t;
+
+static void *
+sms_alloc (struct ast_channel *chan, void *params)
+{
+  return params;
+}
+
+static void
+sms_release (struct ast_channel *chan, void *data)
+{
+  return;
+}
+
+static void sms_messagetx (sms_t * h);
+
+/* copy number, skipping non digits apart from leading + */
+static void
+numcpy (char *d, char *s)
+{
+  if (*s == '+')
+    *d++ = *s++;
+  while (*s)
+    {
+      if (isdigit (*s))
+	*d++ = *s;
+      s++;
+    }
+  *d = 0;
+}
+
+static char *
+isodate (time_t t)
+{				/* static, return a date/time in ISO format */
+  static char date[20];
+  strftime (date, sizeof (date), "%Y-%m-%d %H:%M:%S", localtime (&t));
+  return date;
+}
+
+/* pack n bytes from i to o and return number of bytes */
+static unsigned char
+pack7 (unsigned char *o, unsigned char *i, unsigned char n)
+{
+  unsigned char p = 0, b = 0;
+  /* fixup - map character set perhaps... */
+  o[0] = 0;
+  while (n--)
+    {
+      o[p] |= ((sms8to7[*i] & 0x7F) << b);
+      b += 7;
+      if (b >= 8)
+	{
+	  b -= 8;
+	  p++;
+	  o[p] = ((sms8to7[*i] & 0x7F) >> (7 - b));
+	}
+      i++;
+    }
+  if (b)
+    p++;
+  return p;
+}
+
+/* check if all characters are valid 7 bit coding characters */
+static unsigned char
+check7 (unsigned char l, unsigned char *p)
+{
+  while (l--)
+    if (sms8to7[*p++] & 0x80)
+      return 1;
+  return 0;
+}
+
+/* pack a date and return */
+static void
+packdate (unsigned char *o, time_t w)
+{
+  struct tm *t = localtime (&w);
+  int z = timezone / 3600 / 15;
+  *o++ = ((t->tm_year % 10) << 4) + (t->tm_year % 100) / 10;
+  *o++ = (((t->tm_mon + 1) % 10) << 4) + (t->tm_mon + 1) / 10;
+  *o++ = ((t->tm_mday % 10) << 4) + t->tm_mday / 10;
+  *o++ = ((t->tm_hour % 10) << 4) + t->tm_hour / 10;
+  *o++ = ((t->tm_min % 10) << 4) + t->tm_min / 10;
+  *o++ = ((t->tm_sec % 10) << 4) + t->tm_sec / 10;
+  if (z < 0)
+    *o++ = (((-z) % 10) << 4) + (-z) / 10 + 0x08;
+  else
+    *o++ = ((z % 10) << 4) + z / 10;
+}
+
+/* unpack a date and return */
+static time_t
+unpackdate (unsigned char *i)
+{
+  struct tm t;
+  t.tm_year = 100 + (i[0] & 0xF) * 10 + (i[0] >> 4);
+  t.tm_mon = (i[1] & 0xF) * 10 + (i[1] >> 4) - 1;
+  t.tm_mday = (i[2] & 0xF) * 10 + (i[2] >> 4);
+  t.tm_hour = (i[3] & 0xF) * 10 + (i[3] >> 4);
+  t.tm_min = (i[4] & 0xF) * 10 + (i[4] >> 4);
+  t.tm_sec = (i[5] & 0xF) * 10 + (i[5] >> 4);
+  t.tm_isdst = 0;
+  if (i[6] & 0x08)
+    t.tm_min += 15 * ((i[6] & 0x7) * 10 + (i[6] >> 4));
+  else
+    t.tm_min -= 15 * ((i[6] & 0x7) * 10 + (i[6] >> 4));
+  return mktime (&t);
+}
+
+/* unpack bytes from i to o and return number of source bytes. */
+static unsigned char
+unpack7 (unsigned char *o, unsigned char *i, unsigned char l)
+{
+  unsigned char b = 0, p = 0;
+  while (l--)
+    {
+      if (b < 2)
+	*o++ = sms7to8[((i[p] >> b) & 0x7F)];
+      else
+	*o++ = sms7to8[((((i[p] >> b) + (i[p + 1] << (8 - b)))) & 0x7F)];
+      b += 7;
+      if (b >= 8)
+	{
+	  b -= 8;
+	  p++;
+	}
+    }
+  if (b)
+    p++;
+  return p;
+}
+
+/* unpack an address from i, return byte length, unpack to o */
+static unsigned char
+unpackaddress (char *o, unsigned char *i)
+{
+  unsigned char l = i[0], p;
+  if (i[1] == 0x91)
+    *o++ = '+';
+  for (p = 0; p < l; p++)
+    {
+      if (p & 1)
+	*o++ = (i[2 + p / 2] >> 4) + '0';
+      else
+	*o++ = (i[2 + p / 2] & 0xF) + '0';
+    }
+  *o = 0;
+  return (l + 5) / 2;
+}
+
+/* store an address at o, and return number of bytes used */
+static unsigned char
+packaddress (unsigned char *o, char *i)
+{
+  unsigned char p = 2;
+  o[0] = 0;
+  if (*i == '+')
+    {
+      i++;
+      o[1] = 0x91;
+    }
+  else
+    o[1] = 0x81;
+  while (*i)
+    if (isdigit (*i))
+      {
+	if (o[0] & 1)
+	  o[p++] |= ((*i & 0xF) << 4);
+	else
+	  o[p] = (*i & 0xF);
+	o[0]++;
+	i++;
+      }
+    else
+      i++;
+  if (o[0] & 1)
+    o[p++] |= 0xF0;		/* pad */
+  return p;
+}
+
+static void
+sms_log (sms_t * h, char status)
+{				/* log the output, and remove file */
+  if (*h->oa || *h->da)
+    {
+      int o = open ("/var/log/asterisk/sms", O_CREAT | O_APPEND | O_WRONLY, 0666);
+      if (o >= 0)
+	{
+	  char line[1000], *p;
+	  unsigned char n;
+	  sprintf (line, "%s %c %s %s %s ", isodate (time (0)), status, h->queue, *h->oa ? h->oa : "-",
+		   *h->da ? h->da : "-");
+	  p = line + strlen (line);
+	  for (n = 0; n < h->udl; n++)
+	    if (h->ud[n] == '\\')
+	      {
+		*p++ = '\\';
+		*p++ = '\\';
+	      }
+	    else if (h->ud[n] == '\n')
+	      {
+		*p++ = '\\';
+		*p++ = 'n';
+	      }
+	    else if (h->ud[n] == '\r')
+	      {
+		*p++ = '\\';
+		*p++ = 'r';
+	      }
+	    else if (h->ud[n] < 32 || h->ud[n] == 127)
+	      *p++ = 191;
+	    else
+	      *p++ = h->ud[n];
+	  *p++ = '\n';
+	  *p = 0;
+	  write (o, line, strlen (line));
+	  close (o);
+	}
+      *h->oa = *h->da = h->udl = 0;
+    }
+}
+
+/* parse and delete a file */
+static void
+sms_readfile (sms_t * h, char *fn)
+{
+  char line[1000];
+  FILE *s;
+  char dcsset = 0;		/* if DSC set */
+  ast_log (LOG_EVENT, "Sending %s\n", fn);
+  h->udl = *h->oa = *h->da = h->pid = h->srr = h->rp = h->vp = 0;
+  h->dcs = 0xF1;		/* normal messages class 1 */
+  h->scts = time (0);
+  h->mr = message_ref++;
+  s = fopen (fn, "r");
+  if (s)
+    {
+      if (unlink (fn))
+	{			/* concurrent access, we lost */
+	  fclose (s);
+	  return;
+	}
+      while (fgets (line, sizeof (line), s))
+	{			/* process line in file */
+	  char *p;
+	  for (p = line; *p && *p != '\n' && *p != '\r'; p++);
+	  *p = 0;		/* strip eoln */
+	  //ast_log (LOG_EVENT, "Line %s\n", line);
+	  p = line;
+	  if (!*p || *p == ';')
+	    continue;		/* blank line or comment, ignore */
+	  while (isalnum (*p))
+	    {
+	      *p = tolower (*p);
+	      p++;
+	    }
+	  while (isspace (*p))
+	    *p++ = 0;
+	  if (*p == '=')
+	    {
+	      *p++ = 0;
+	      if (!strcmp (line, "ud"))
+		{		/* parse message */
+		  unsigned char o = 0;
+		  while (*p && o < 160)
+		    {
+		      if (*p == '\\')
+			{
+			  p++;
+			  if (*p == '\\')
+			    h->ud[o++] = *p++;
+			  else if (*p == 'n')
+			    {
+			      h->ud[o++] = '\n';
+			      p++;
+			    }
+			  else if (*p == 'r')
+			    {
+			      h->ud[o++] = '\r';
+			      p++;
+			    }
+			}
+		      else
+			h->ud[o++] = *p++;
+		    }
+		  h->udl = o;
+		  if (*p)
+		    ast_log (LOG_WARNING, "UD too long in %s\n", fn);
+		}
+	      else
+		{
+		  while (isspace (*p))
+		    p++;
+		  if (!strcmp (line, "oa") && strlen (p) < sizeof (h->oa))
+		    numcpy (h->oa, p);
+		  else if (!strcmp (line, "da") && strlen (p) < sizeof (h->oa))
+		    numcpy (h->da, p);
+		  else if (!strcmp (line, "pid"))
+		    h->pid = atoi (p);
+		  else if (!strcmp (line, "dcs"))
+		    {
+		      h->dcs = atoi (p);
+		      dcsset = 1;
+		    }
+		  else if (!strcmp (line, "mr"))
+		    h->mr = atoi (p);
+		  else if (!strcmp (line, "srr"))
+		    h->srr = (atoi (p) ? 1 : 0);
+		  else if (!strcmp (line, "vp"))
+		    h->vp = atoi (p);
+		  else if (!strcmp (line, "rp"))
+		    h->rp = (atoi (p) ? 1 : 0);
+		  else if (!strcmp (line, "scts"))
+		    {		/* get date/time */
+		      int Y, m, d, H, M, S;
+		      if (sscanf (p, "%d-%d-%d %d:%d:%d", &Y, &m, &d, &H, &M, &S) == 6)
+			{
+			  struct tm t;
+			  t.tm_year = Y - 1900;
+			  t.tm_mon = m - 1;
+			  t.tm_mday = d;
+			  t.tm_hour = H;
+			  t.tm_min = M;
+			  t.tm_sec = S;
+			  t.tm_isdst = -1;
+			  h->scts = mktime (&t);
+			  if (h->scts == (time_t) - 1)
+			    ast_log (LOG_WARNING, "Bad date/timein %s: %s", fn, p);
+			}
+		    }
+		  else
+		    ast_log (LOG_WARNING, "Cannot parse in %s: %s=%si\n", fn, line, p);
+		}
+	    }
+	  else if (*p == '#')
+	    {			/* raw hex format */
+	      *p++ = 0;
+	      if (!strcmp (line, "ud"))
+		{
+		  unsigned char o = 0;
+		  while (*p && o < 160)
+		    {
+		      if (isxdigit (*p) && isxdigit (p[1]))
+			{
+			  h->ud[o] =
+			    (((isalpha (*p) ? 9 : 0) + (*p & 0xF)) << 4) + ((isalpha (p[1]) ? 9 : 0) + (p[1] & 0xF));
+			  o++;
+			  p += 2;
+			}
+		      else
+			break;
+		    }
+		  h->udl = o;
+		  if (*p)
+		    ast_log (LOG_WARNING, "UD too long / invalid hex in %s\n", fn);
+		}
+	      else
+		ast_log (LOG_WARNING, "Only ud can use 8 bit key format with # instead of =\n");
+	    }
+	  else
+	    ast_log (LOG_WARNING, "Cannot parse in %s: %s\n", fn, line);
+	}
+      fclose (s);
+      if (!dcsset && h->udl <= 140 && check7 (h->udl, h->ud))
+	{
+	  h->dcs = 0xF5;	// default to 8 bit
+	  ast_log (LOG_WARNING, "Sending in 8 bit format because of illegal characters %s\n", fn);
+	}
+      if ((h->dcs & 4) && h->udl > 140)
+	{
+	  ast_log (LOG_WARNING, "8 bit data too long, truncated %s\n", fn);
+	  h->udl = 140;
+	}
+      else if (!(h->dcs & 4) && check7 (h->udl, h->ud))
+	ast_log (LOG_WARNING, "Invalid 7 bit GSM data %s\n", fn);
+    }
+  //ast_log (LOG_EVENT, "Loaded %s\n", fn);
+}
+
+/* white a received text message to a file */
+static void
+sms_writefile (sms_t * h)
+{
+  char fn[200], fn2[200];
+  FILE *o;
+  strcpy (fn, "/var/spool/asterisk/sms");
+  mkdir (fn, 0777);		/* ensure it exists */
+  sprintf (fn + strlen (fn), "/%s.%s", h->smsc ? "me-sc" : "sc-me", h->queue);
+  mkdir (fn, 0777);		/* ensure it exists */
+  strcpy (fn2, fn);
+  strftime (fn2 + strlen (fn2), 30, "/%Y-%m-%d_%H:%M:%S", localtime (&h->scts));
+  sprintf (fn2 + strlen (fn2), "-%02X", h->mr);
+  sprintf (fn + strlen (fn), "/.%s", fn2 + strlen (fn) + 1);
+  o = fopen (fn, "w");
+  if (o)
+    {
+      fprintf (o, "mr=%d\n", h->mr);
+      if (*h->oa)
+	fprintf (o, "oa=%s\n", h->oa);
+      if (*h->da)
+	fprintf (o, "da=%s\n", h->da);
+      if (h->pid)
+	fprintf (o, "pid=%d\n", h->pid);
+      if (h->dcs != 0xF1)
+	fprintf (o, "dcs=%d\n", h->dcs);
+      if (h->vp)
+	fprintf (o, "srr=%d\n", h->vp);
+      if (h->srr)
+	fprintf (o, "srr=1\n");
+      if (h->rp)
+	fprintf (o, "rp=1\n");
+      if (h->scts)
+	fprintf (o, "scts=%s\n", isodate (h->scts));
+      if (h->udl)
+	{
+	  unsigned int p;
+	  for (p = 0; p < h->udl && ((h->ud[p] >= 32 && h->ud[p] != 127) || h->ud[p] == '\n' || h->ud[p] == '\r'); p++);
+	  if (p < h->udl)
+	    {			// use a hex format as unprintable characters
+	      fprintf (o, "ud#");
+	      for (p = 0; p < h->udl; p++)
+		fprintf (o, "%02X", h->ud[p]);
+	      fprintf (o, "\n;");
+	      /* followed by commented line using printable characters */
+	    }
+	  fprintf (o, "ud=");
+	  for (p = 0; p < h->udl; p++)
+	    {
+	      if (h->ud[p] == '\\')
+		fprintf (o, "\\\\");
+	      else if (h->ud[p] == '\r')
+		fprintf (o, "\\r");
+	      else if (h->ud[p] == '\n')
+		fprintf (o, "\\n");
+	      else if (h->ud[p] < 32 || h->ud[p] == 127)
+		fputc (191, o);
+	      else
+		fputc (h->ud[p], o);
+	    }
+	  fprintf (o, "\n");
+	}
+      fclose (o);
+      if (rename (fn, fn2))
+	unlink (fn);
+      else
+	ast_log (LOG_EVENT, "Received to %s\n", fn2);
+    }
+}
+
+/* read dir skipping dot files... */
+static struct dirent *
+readdirdot (DIR * d)
+{
+  struct dirent *f;
+  do
+    {
+      f = readdir (d);
+    }
+  while (f && *f->d_name == '.');
+  return f;
+}
+
+/* handle the incoming message */
+static unsigned char
+sms_handleincoming (sms_t * h)
+{
+  unsigned char p = 3;
+  if (h->smsc)
+    {				/* SMSC */
+      if ((h->imsg[2] & 3) == 1)
+	{			/* SMS-SUBMIT */
+	  h->vp = 0;
+	  h->srr = ((h->imsg[2] & 0x20) ? 1 : 0);
+	  h->rp = ((h->imsg[2] & 0x80) ? 1 : 0);
+	  strcpy (h->oa, h->cli);
+	  h->scts = time (0);
+	  h->mr = h->imsg[p++];
+	  p += unpackaddress (h->da, h->imsg + p);
+	  h->pid = h->imsg[p++];
+	  h->dcs = h->imsg[p++];
+	  if ((h->imsg[2] & 0x18) == 0x10)
+	    {			/* relative VP */
+	      if (h->imsg[p] < 144)
+		h->vp = (h->imsg[p] + 1) * 5;
+	      else if (h->imsg[p] < 168)
+		h->vp = 720 + (h->imsg[p] - 143) * 30;
+	      else if (h->imsg[p] < 197)
+		h->vp = (h->imsg[p] - 166) * 1440;
+	      else
+		h->vp = (h->imsg[p] - 192) * 10080;
+	      p++;
+	    }
+	  else if (h->imsg[2] & 0x18)
+	    p += 7;		/* ignore enhanced / absolute VP */
+	  h->udl = h->imsg[p++];
+	  if (h->udl)
+	    {
+	      if (h->dcs & 4)
+		{
+		  memcpy (h->ud, h->imsg + p, h->udl);
+		  p += h->udl;
+		}
+	      else
+		p += unpack7 (h->ud, h->imsg + p, h->udl);
+	    }
+	  sms_writefile (h);	/* write the file */
+	  if (p != h->imsg[1] + 2)
+	    return 0xFF;	/* duh! */
+	}
+      else
+	{
+	  ast_log (LOG_WARNING, "Unknown message type %02X\n", h->imsg[2]);
+	  return 0xFF;
+	}
+    }
+  else
+    {				/* client */
+      if (!(h->imsg[2] & 3))
+	{			/* SMS-DELIVER */
+	  *h->da = h->srr = h->rp = h->vp = 0;
+	  h->mr = message_ref++;
+	  p += unpackaddress (h->oa, h->imsg + p);
+	  h->pid = h->imsg[p++];
+	  h->dcs = h->imsg[p++];
+	  h->scts = unpackdate (h->imsg + p);
+	  p += 7;
+	  h->udl = h->imsg[p++];
+	  if (h->udl)
+	    {
+	      if (h->dcs & 4)
+		{
+		  memcpy (h->ud, h->imsg + p, h->udl);
+		  p += h->udl;
+		}
+	      else
+		p += unpack7 (h->ud, h->imsg + p, h->udl);
+	    }
+	  sms_writefile (h);	/* write the file */
+	  if (p != h->imsg[1] + 2)
+	    return 0xFF;	/* duh! */
+	}
+      else
+	{
+	  ast_log (LOG_WARNING, "Unknown message type %02X\n", h->imsg[2]);
+	  return 0xFF;
+	}
+    }
+  return 0;			/* no error */
+}
+
+static void
+sms_nextoutgoing (sms_t * h)
+{				/* find and fill in next message, or send a REL if none waiting */
+  char fn[100 + NAME_MAX];
+  DIR *d;
+  char more = 0;
+  strcpy (fn, "/var/spool/asterisk/sms");
+  mkdir (fn, 0777);		/* ensure it exists */
+  sprintf (fn + strlen (fn), "/%s.%s", h->smsc ? "sc-me" : "me-sc", h->queue);
+  mkdir (fn, 0777);		/* ensure it exists */
+  d = opendir (fn);
+  if (d)
+    {
+      struct dirent *f = readdirdot (d);
+      if (f)
+	{
+	  sprintf (fn + strlen (fn), "/%s", f->d_name);
+	  sms_readfile (h, fn);
+	  if (readdirdot (d))
+	    more = 1;		/* more to send */
+	}
+      closedir (d);
+    }
+  if (*h->da || *h->oa)
+    {				/* message to send */
+      unsigned char p = 2;
+      h->omsg[0] = 0x91;	/* SMS_DATA */
+      if (h->smsc)
+	{			/* deliver */
+	  h->omsg[p++] = (more ? 4 : 0);
+	  p += packaddress (h->omsg + p, h->oa);
+	  h->omsg[p++] = h->pid;
+	  h->omsg[p++] = h->dcs;
+	  packdate (h->omsg + p, h->scts);
+	  p += 7;
+	  h->omsg[p++] = h->udl;
+	  if (h->udl)
+	    {
+	      if (h->dcs & 4)
+		{
+		  memcpy (h->omsg + p, h->ud, h->udl);
+		  p += h->udl;
+		}
+	      else
+		p += pack7 (h->omsg + p, h->ud, h->udl);
+	    }
+	}
+      else
+	{			/* submit */
+	  h->omsg[p++] = 0x01 + (more ? 4 : 0) + (h->srr ? 0x20 : 0) + (h->rp ? 0x80 : 0) + (h->vp ? 0x10 : 0);
+	  h->omsg[p++] = h->mr;
+	  p += packaddress (h->omsg + p, h->da);
+	  h->omsg[p++] = h->pid;
+	  h->omsg[p++] = h->dcs;
+	  if (h->vp)
+	    {			/* relative VP */
+	      if (h->vp < 720)
+		h->omsg[p++] = (h->vp + 4) / 5 - 1;
+	      else if (h->vp < 1440)
+		h->omsg[p++] = (h->vp - 720 + 29) / 30 + 143;
+	      else if (h->vp < 43200)
+		h->omsg[p++] = (h->vp + 1439) / 1440 + 166;
+	      else if (h->vp < 635040)
+		h->omsg[p++] = (h->vp + 10079) / 10080 + 192;
+	      else
+		h->omsg[p++] = 255;	/* max */
+	    }
+	  h->omsg[p++] = h->udl;
+	  if (h->udl)
+	    {
+	      if (h->dcs & 4)
+		{
+		  memcpy (h->omsg + p, h->ud, h->udl);
+		  p += h->udl;
+		}
+	      else
+		p += pack7 (h->omsg + p, h->ud, h->udl);
+	    }
+	}
+      h->omsg[1] = p - 2;
+      sms_messagetx (h);
+    }
+  else
+    {				/* no message */
+      h->omsg[0] = 0x94;	/* SMS_REL */
+      h->omsg[1] = 0;
+      sms_messagetx (h);
+    }
+}
+
+static void
+sms_messagerx (sms_t * h)
+{
+  ast_verbose (VERBOSE_PREFIX_3 "SMS RX %02X %02X %02X %02X %02X %02X...\n", h->imsg[0], h->imsg[1], h->imsg[2],
+	       h->imsg[3], h->imsg[4], h->imsg[5]);
+  /* testing */
+  switch (h->imsg[0])
+    {
+    case 0x91:			/* SMS_DATA */
+      {
+	unsigned char cause = sms_handleincoming (h);
+	if (!cause)
+	  {
+	    sms_log (h, 'Y');
+	    h->omsg[0] = 0x95;	/* SMS_ACK */
+	    h->omsg[1] = 0x02;
+	    h->omsg[2] = 0x00;	/* deliver report */
+	    h->omsg[3] = 0x00;	/* no parameters */
+	  }
+	else
+	  {			/* NACK */
+	    sms_log (h, 'N');
+	    h->omsg[0] = 0x96;	/* SMS_NACK */
+	    h->omsg[1] = 3;
+	    h->omsg[2] = 0;	/* delivery report */
+	    h->omsg[3] = cause;	/* cause */
+	    h->omsg[4] = 0;	/* no parameters */
+	  }
+	sms_messagetx (h);
+      }
+      break;
+    case 0x92:			/* SMS_ERROR */
+      sms_messagetx (h);	/* send whatever we sent again */
+      break;
+    case 0x93:			/* SMS_EST */
+      sms_nextoutgoing (h);
+      break;
+    case 0x94:			/* SMS_REL */
+      h->hangup = 1;		/* hangup */
+      break;
+    case 0x95:			/* SMS_ACK */
+      sms_log (h, 'Y');
+      sms_nextoutgoing (h);
+      break;
+    case 0x96:			/* SMS_NACK */
+      sms_log (h, 'N');
+      sms_nextoutgoing (h);
+      break;
+    default:			/* Unknown */
+      h->omsg[0] = 0x92;	/* SMS_ERROR */
+      h->omsg[1] = 1;
+      h->omsg[2] = 3;		/* unknown message type; */
+      sms_messagetx (h);
+      break;
+    }
+}
+
+static void
+sms_messagetx (sms_t * h)
+{
+  unsigned char c = 0, p;
+  for (p = 0; p < h->omsg[1] + 2; p++)
+    c += h->omsg[p];
+  h->omsg[h->omsg[1] + 2] = 0 - c;
+  ast_verbose (VERBOSE_PREFIX_3 "SMS TX %02X %02X %02X %02X %02X %02X...\n", h->omsg[0], h->omsg[1], h->omsg[2],
+	       h->omsg[3], h->omsg[4], h->omsg[5]);
+  h->obyte = 1;
+  h->opause = 200;
+  if (h->omsg[0] == 0x93)
+    h->opause = 2400;		/* initial message delay 300ms (for BT) */
+  h->obytep = 0;
+  h->obitp = 0;
+  h->osync = 80;
+  h->obyten = h->omsg[1] + 3;
+}
+
+
+static int
+sms_generate (struct ast_channel *chan, void *data, int len, int samples)
+{
+  struct ast_frame f;
+  unsigned char waste[AST_FRIENDLY_OFFSET];
+  signed short buf[800];
+  sms_t *h = data;
+  int i;
+
+  if (len > sizeof (buf))
+    {
+      ast_log (LOG_WARNING, "Only doing %d bytes (%d bytes requested)\n", sizeof (buf) / sizeof (signed short), len);
+      len = sizeof (buf);
+      samples = len / 2;
+    }
+  waste[0] = 0;			/* make compiler happy */
+  f.frametype = AST_FRAME_VOICE;
+  f.subclass = AST_FORMAT_SLINEAR;
+  f.offset = AST_FRIENDLY_OFFSET;
+  f.mallocd = 0;
+  f.data = buf;
+  f.datalen = samples * 2;
+  f.samples = samples;
+  f.src = "app_sms";
+  /* create a buffer containing the digital sms pattern */
+  for (i = 0; i < samples; i++)
+    {
+      buf[i] = 0;
+      if (h->opause)
+	h->opause--;
+      else if (h->obyten || h->osync)
+	{			/* sending data */
+	  buf[i] = wave[h->ophase];
+	  if ((h->ophase += ((h->obyte & 1) ? 13 : 21)) >= 80)
+	    h->ophase -= 80;
+	  if ((h->ophasep += 12) >= 80)
+	    {			/* next bit */
+	      h->ophasep -= 80;
+	      if (h->osync)
+		h->osync--;	/* sending sync bits */
+	      else
+		{
+		  h->obyte >>= 1;
+		  h->obitp++;
+		  if (h->obitp == 1)
+		    h->obyte = 0;	/* start bit; */
+		  else if (h->obitp == 2)
+		    h->obyte = h->omsg[h->obytep];
+		  else if (h->obitp == 10)
+		    {
+		      h->obyte = 1;	/* stop bit */
+		      h->obitp = 0;
+		      h->obytep++;
+		      if (h->obytep == h->obyten)
+			{
+			  h->obytep = h->obyten = 0;	/* sent */
+			  h->osync = 10;	/* trailing marks */
+			}
+		    }
+		}
+	    }
+	}
+    }
+  if (ast_write (chan, &f) < 0)
+    {
+      ast_log (LOG_WARNING, "Failed to write frame to '%s': %s\n", chan->name, strerror (errno));
+      return -1;
+    }
+  return 0;
+}
+
+static void
+sms_process (sms_t * h, int samples, signed short *data)
+{
+  if (h->obyten || h->osync)
+    return;			/* sending */
+  while (samples--)
+    {
+      unsigned long long m0, m1;
+      if (abs (*data) > h->imag)
+	h->imag = abs (*data);
+      else
+	h->imag = h->imag * 7 / 8;
+      if (h->imag > 500)
+	{
+	  h->ims0 = (h->ims0 * 6 + *data * wave[h->ips0]) / 7;
+	  h->idle = 0;
+	  h->imc0 = (h->imc0 * 6 + *data * wave[h->ipc0]) / 7;
+	  h->ims1 = (h->ims1 * 6 + *data * wave[h->ips1]) / 7;
+	  h->imc1 = (h->imc1 * 6 + *data * wave[h->ipc1]) / 7;
+	  m0 = h->ims0 * h->ims0 + h->imc0 * h->imc0;
+	  m1 = h->ims1 * h->ims1 + h->imc1 * h->imc1;
+	  if ((h->ips0 += 21) >= 80)
+	    h->ips0 -= 80;
+	  if ((h->ipc0 += 21) >= 80)
+	    h->ipc0 -= 80;
+	  if ((h->ips1 += 13) >= 80)
+	    h->ips1 -= 80;
+	  if ((h->ipc1 += 13) >= 80)
+	    h->ipc1 -= 80;
+	  {
+	    char bit;
+	    h->ibith <<= 1;
+	    if (m1 > m0)
+	      h->ibith |= 1;
+	    if (h->ibith & 8)
+	      h->ibitt--;
+	    if (h->ibith & 1)
+	      h->ibitt++;
+	    bit = ((h->ibitt > 1) ? 1 : 0);
+	    if (bit != h->ibitl)
+	      h->ibitc = 1;
+	    else
+	      h->ibitc++;
+	    h->ibitl = bit;
+	    if (!h->ibitn && h->ibitc == 4 && !bit)
+	      {
+		h->ibitn = 1;
+		h->iphasep = 0;
+	      }
+	    if (bit && h->ibitc == 200)
+	      {			/* sync, restart message */
+		h->ierr = h->ibitn = h->ibytep = h->ibytec = 0;
+	      }
+	    if (h->ibitn)
+	      {
+		h->iphasep += 12;
+		if (h->iphasep >= 80)
+		  {		/* next bit */
+		    h->iphasep -= 80;
+		    if (h->ibitn++ == 9)
+		      {		/* end of byte */
+			if (!bit)	/* bad stop bit */
+			  h->ierr = 0xFF;	/* unknown error */
+			else
+			  {
+			    if (h->ibytep < sizeof (h->imsg))
+			      {
+				h->imsg[h->ibytep] = h->ibytev;
+				h->ibytec += h->ibytev;
+				h->ibytep++;
+			      }
+			    else if (h->ibytep == sizeof (h->imsg))
+			      h->ierr = 2;	/* bad message length */
+			    if (h->ibytep > 1 && h->ibytep == 3 + h->imsg[1] && !h->ierr)
+			      {
+				if (!h->ibytec)
+				  sms_messagerx (h);
+				else
+				  h->ierr = 1;	/* bad checksum */
+			      }
+			  }
+			h->ibitn = 0;
+		      }
+		    h->ibytev = (h->ibytev >> 1) + (bit ? 0x80 : 0);
+		  }
+	      }
+	  }
+	}
+      else
+	{			/* lost carrier */
+	  if (h->idle++ == 80000)
+	    {			/* nothing happening */
+	      ast_log (LOG_EVENT, "No data, hanging up\n");
+	      h->hangup = 1;
+	    }
+	  if (h->ierr)
+	    {			/* error */
+	      h->omsg[0] = 0x92;	/* error */
+	      h->omsg[1] = 1;
+	      h->omsg[2] = h->ierr;
+	      sms_messagetx (h);	/* send error */
+	    }
+	  h->ierr = h->ibitn = h->ibytep = h->ibytec = 0;
+	}
+      data++;
+    }
+}
+
+static struct ast_generator smsgen = {
+alloc:sms_alloc,
+release:sms_release,
+generate:sms_generate,
+};
+
+static int
+sms_exec (struct ast_channel *chan, void *data)
+{
+  int res = -1;
+  struct localuser *u;
+  struct ast_frame *f;
+  sms_t h = { 0 };
+  h.ipc0 = h.ipc1 = 20;		/* phase for cosine */
+  h.dcs = 0xF1;			/* default */
+  if (!data)
+    {
+      ast_log (LOG_ERROR, "Requires queue name at least\n");
+      return -1;
+    }
+
+  if (chan->callerid)
+    {				/* get caller ID. Used as originating address on sc side receives */
+      char temp[256], *name, *num;
+      strncpy (temp, chan->callerid, sizeof (temp));
+      ast_callerid_parse (temp, &name, &num);
+      if (!num)
+	num = temp;
+      ast_shrink_phone_number (num);
+      if (strlen (num) < sizeof (h.cli))
+	strcpy (h.cli, num);
+    }
+
+  {
+    char *d = data, *p, answer = 0;
+    if (!*d || *d == '|')
+      {
+	ast_log (LOG_ERROR, "Requires queue name\n");
+	return -1;
+      }
+    for (p = d; *p && *p != '|'; p++);
+    if (p - d >= sizeof (h.queue))
+      {
+	ast_log (LOG_ERROR, "Queue name too long\n");
+	return -1;
+      }
+    strncpy (h.queue, d, p - d);
+    if (*p == '|')
+      p++;
+    d = p;
+    for (p = h.queue; *p; p++)
+      if (!isalnum (*p))
+	*p = '-';		/* make very safe for filenames */
+    while (*d && *d != '|')
+      {
+	switch (*d)
+	  {
+	  case 'a':		/* we have to send the initial FSK sequence */
+	    answer = 1;
+	    break;
+	  case 's':		/* we are acting as a service centre talking to a phone */
+	    h.smsc = 1;
+	    break;
+	    /* the following apply if there is an arg3/4 and apply to the created message file */
+	  case 'r':
+	    h.srr = 1;
+	    break;
+	  case 'o':
+	    h.dcs |= 4;		/* octets */
+	    break;
+	  case '1':
+	  case '2':
+	  case '3':
+	  case '4':
+	  case '5':
+	  case '6':
+	  case '7':		/* set the pid for saved local message */
+	    h.pid = 0x40 + (*d & 0xF);
+	    break;
+	  }
+	d++;
+      }
+    if (*d == '|')
+      {				/* submitting a message, not taking call. */
+	d++;
+	h.scts = time (0);
+	for (p = d; *p && *p != '|'; p++);
+	if (*p)
+	  *p++ = 0;
+	if (strlen (d) >= sizeof (h.oa))
+	  {
+	    ast_log (LOG_ERROR, "Address too long %s\n", d);
+	    return 0;
+	  }
+	strcpy (h.smsc ? h.oa : h.da, d);
+	if (!h.smsc)
+	  strcpy (h.oa, h.cli);
+	d = p;
+	if (!(h.dcs & 4) && check7 (h.udl, h.ud))
+	  ast_log (LOG_WARNING, "Invalid GSM characters in %.*s\n", h.udl, h.ud);
+	if (strlen (d) > ((h.dcs & 4) ? 140 : 160))
+	  {
+	    ast_log (LOG_ERROR, "Message too long %s\n", d);
+	    h.udl = ((h.dcs & 4) ? 140 : 160);
+	  }
+	else
+	  h.udl = strlen (d);
+	if (h.udl)
+	  memcpy (h.ud, d, h.udl);
+	h.smsc = !h.smsc;	/* file woul go in wrong directory otherwise... */
+	sms_writefile (&h);
+	return 0;
+      }
+
+    if (answer)
+      {				/* set up SMS_EST initial message */
+	h.omsg[0] = 0x93;
+	h.omsg[1] = 0;
+	sms_messagetx (&h);
+      }
+  }
+
+  LOCAL_USER_ADD (u);
+  if (chan->_state != AST_STATE_UP)
+    ast_answer (chan);
+
+  res = ast_set_write_format (chan, AST_FORMAT_SLINEAR);
+  if (res >= 0)
+    res = ast_set_read_format (chan, AST_FORMAT_SLINEAR);
+  if (res < 0)
+    {
+      LOCAL_USER_REMOVE (u);
+      ast_log (LOG_ERROR, "Unable to set to linear mode, giving up\n");
+      return -1;
+    }
+
+  if (ast_activate_generator (chan, &smsgen, &h) < 0)
+    {
+      LOCAL_USER_REMOVE (u);
+      ast_log (LOG_ERROR, "Failed to activate generator on '%s'\n", chan->name);
+      return -1;
+    }
+
+  /* Do our thing here */
+  while (ast_waitfor (chan, -1) > -1 && !h.hangup)
+    {
+      f = ast_read (chan);
+      if (!f)
+	break;
+      if (f->frametype == AST_FRAME_VOICE)
+	{
+	  sms_process (&h, f->samples, f->data);
+	}
+
+      ast_frfree (f);
+    }
+
+  sms_log (&h, '?');		/* log incomplete message */
+
+  LOCAL_USER_REMOVE (u);
+  return h.hangup;
+}
+
+int
+unload_module (void)
+{
+  STANDARD_HANGUP_LOCALUSERS;
+  return ast_unregister_application (app);
+}
+
+int
+load_module (void)
+{
+  {				/* fill in sms8to7 from sms7to8 */
+    int p;
+    for (p = 0; p < 256; p++)
+      sms8to7[p] = 0xE0;	/* inverted question mark and invalid */
+    for (p = 0; p < 128; p++)
+      sms8to7[sms7to8[p]] = p;
+  }
+  return ast_register_application (app, sms_exec, synopsis, descrip);
+}
+
+char *
+description (void)
+{
+  return tdesc;
+}
+
+int
+usecount (void)
+{
+  int res;
+  STANDARD_USECOUNT (res);
+  return res;
+}
+
+char *
+key ()
+{
+  return ASTERISK_GPL_KEY;
+}
diff --git a/doc/README.sms b/doc/README.sms
new file mode 100755
index 000000000..f4b75a84e
--- /dev/null
+++ b/doc/README.sms
@@ -0,0 +1,136 @@
+SMS() is an application to handles calls to/from text message capable phones and message centres using ETSI ES 201 912 protocol 1 FSK messaging over analogue calls.
+
+Basically it allows sending and receiving of text messages over the PSTN. It is compatible with BT Text service in the UK and works on ISDN and PSTN lines. It is designed to connect to an ISDN or zap interface directly and uses FSK so would probably not work over any sort of compressed link.
+
+Typical applications include:-
+
+1. Connection to a message centre to send text messages - probably initiated via the manager interface or "outgoing" directory
+2. Connection to an POTS line with an SMS capable phone to send messages - probably initiated via the manager interface or "Outgoing" directory
+3. Acceptance of calls from the message centre (based on CLI) and storage of received messages
+4. Acceptance of calls from a POTS line with an SMS capable phone and storage of received messages
+
+First argument is queue name
+
+Second is options
+
+ a: SMS() is to act as the answering side, and so send the initial FSK frame
+ s: SMS() is to act as a service centre side rather than as terminal equipment
+
+If a third argument is specified, then SMS does not handle the call at all,
+but takes the third argument as a destination number to send an SMS to, and
+the forth argument onward as a message to be queued. All this does is create
+the file in the me-sc directory. If 's' is set then the number is the source
+address and the message placed in the sc-me directory.
+
+All text messages are in /var/spool/asterisk/sms
+A log is recorded in /var/log/asterisk/sms
+
+There are two subdirectories called sc-me.<queuename> holding all
+messages from service centre to phone, and me-sc.<queuename> holding all
+messages from phone to service centre.
+
+In each directory are messages in files, one per file, using any filename not
+starting with a dot.
+
+When connected as a service centre, SMS(s) will send all messages waiting in
+the sc-me-<queuename> directory, deleting the files as it goes. Any
+received in this mode are placed in the me-sc-<queuename> directory.
+
+When connected as a client, SMS() will send all messages waiting in the
+me-sc-<queuename> directory, deleting the files as it goes. Any received in
+this mode are placed in the sc-me-<queuename> directory.
+
+Message files created by SMS() use a time stamp/reference based filename.
+
+The format of the sms file is lines that have the form of key=value
+Keys are :-
+
+oa	Originating Address
+	Telephone number, national number if just digits
+	Telephone number starting with + then digits for international
+	Ignored on sending messages to service centre (CLI used)
+da	Destination Address
+	Telephone number, national number if just digits
+	Telephone number starting with + then digits for international
+scts	Service Centre Time Stamp
+	In the format YYYY-MM-DD HH:MM:SS
+pid	Protocol Identifier (decimal octet value)
+dcs	Data coding scheme (decimal octet value)
+mr	Message reference (decimal octet value)
+ud	The message (see escaping below)
+srr	0/1 Status Report Request
+rp	0/1 Return Path
+vp	mins validity period
+
+Omitted fields have default values.
+
+Note that there is special format for ud, ud# instead of ud= which is followed
+by raw hex (2 characters per octet). This is used in output where characters
+other than 10,13,32-126,128-255 are included in the data. In this case a comment (line
+starting ;) is added showing the printable characters
+
+When generating files to send to a service centre, only da and ud need be
+specified. oa is ignored.
+
+When generating files to send to a phone, only oa and ud need be specified. da is ignored.
+
+When receing a message as a service centre, only the destination address is
+sent, so the originating address is set to the callerid.
+
+EXAMPLES
+
+The following are examples of use within the UK using BT Text SMS/landline
+service.
+
+This is a context to use with a manager script.
+
+[smsdial]       ; create and send a text message, expects number+message and
+connect to 17094009
+exten = _X.,1,SMS(${CALLERIDNUM},,${EXTEN},${CALLERIDNAME})
+exten = _X.,2,SMS(${CALLERIDNUM})
+exten = _X.,3,Hangup
+
+The script sends
+
+action: originate
+callerid: message <from>
+exten: to
+channel: Local/17094009
+context: smsdial
+priority: 1
+
+You put the message as the name of the caller ID (messy, I know), the
+originating number and hence queue name as the number of the caller ID and the
+exten as the number to which the sms is to be sent. The context uses SMS to
+create the message in the queue and then SMS to communicate iwth 17094009 to
+actually send the message.
+
+Note that the 9 on the end of 17094009 is the sub address 9 meaning no sub
+address (BT specific). If a different digit is used then that is the sub
+address for the sending message source address (appended to the outgoing CLI
+by BT).
+
+For incoming calls you can use a context like this :-
+
+[incoming]
+exten = _XXXXXX/_8005875290,1,SMS(${EXTEN:3},a)
+exten = _XXXXXX/_8005875290,2,System(/usr/lib/asterisk/smsin ${EXTEN:3})
+exten = _XXXXXX/_80058752[0-8]0,1,SMS(${EXTEN:3}${CALLERIDNUM:8:1},a)
+exten = _XXXXXX/_80058752[0-8]0,2,System(/usr/lib/asterisk/smsin
+${EXTEN:3}${CALLERIDNUM:8:1})
+exten = _XXXXXX/_80058752X0,3,Hangup
+
+
+In this case the called number we get from BT is 6 digits (XXXXXX) and we are
+using the last 3 digits as the queue name.
+
+Priority 1 causes the SMS to be received and processed for the incoming call.
+It is from 080058752X0. The two versions handle the queue name as 3 digits (no
+sub address) or 4 digits (with sub address). In both cases, after the call a
+script (smsin) is run - this is optional, but is useful to actually processed
+the received queued SMS. In our case we email them based on the target number.
+Priority 3 hangs up.
+
+If using the CAPI drivers they send the right CLI and so the _800... would be
+_0800...
+