Asterisk & Fixed line SMS in the UK

Hi there - newbie to all this so please be gentle…

I’ve installed Asterisk 1.6.2.4 on Fedora 11 box with a Digium TDMP400P card and I think it’s working. I can make it dial out over PSTN and ring a completely separate phone, I can also answer incoming calls and playback the “Welcome to Asterisk” message. What I really want to do with it is to have the box act as an SMS gateway to send and receive SMS messages via the BT Text fixed line SMS service in the UK. I have created my dial plan with the correct BT fixed line SMSC numbers in it and when the BT fixed line SMSC tries to deliver an SMS to the Asterisk box via the PSTN the Asterisk box wakes up, goes to the correct context and attempts to answer the SMS. There are some bytes exchanged between the SMSC and the Asterisk box then for some reason one end hangs up. The following is displayed on the screen:

AsteriskSMS*CLI> == Starting post polarity CID detection on channel 4 -- Starting simple switch on 'DAHDI/4-1' [Feb 23 13:44:44] NOTICE[2275]: chan_dahdi.c:8463 ss_thread: CallerID number: 08005875290, name: (null), flags=4 -- Executing [s@incoming:1] Answer("DAHDI/4-1", "") in new stack -- Executing [s@incoming:2] Wait("DAHDI/4-1", "0.3") in new stack -- Executing [s@incoming:3] NoOp("DAHDI/4-1", "Incoming call") in new stack -- Executing [s@incoming:4] GotoIf("DAHDI/4-1", "1?smsmtrx,mysms,1:nosmssc") in new stack -- Goto (smsmtrx,mysms,1) -- Executing [mysms@smsmtrx:1] NoOp("DAHDI/4-1", "Processing incoming SMS") in new stack -- Executing [mysms@smsmtrx:2] SMS("DAHDI/4-1", "mtrx/,ap(300)") in new stack sms argc 2 queue <mtrx/> opts <ap(300)> addr <> body <> initial delay 300ms -- SMS TX 93 00 -- SMS RX 93 00 6D -- SMS TX 94 00 [Feb 23 13:44:47] NOTICE[2275]: app_sms.c:1800 sms_process: bad stop bit[Feb 23 13:44:47] NOTICE[2275]: app_sms.c:1723 sms_process: Error 255, hanging up -- SMS TX 92 01 FF [Feb 23 13:44:47] NOTICE[2275]: app_sms.c:1800 sms_process: bad stop bit[Feb 23 13:44:47] NOTICE[2275]: app_sms.c:1723 sms_process: Error 255, hanging up -- SMS TX 92 01 FF [Feb 23 13:44:47] NOTICE[2275]: app_sms.c:1800 sms_process: bad stop bit[Feb 23 13:44:47] NOTICE[2275]: app_sms.c:1723 sms_process: Error 255, hanging up -- SMS TX 92 01 FF [Feb 23 13:44:47] NOTICE[2275]: app_sms.c:2031 sms_exec: ast_read failed == Spawn extension (smsmtrx, mysms, 2) exited non-zero on 'DAHDI/4-1' -- Executing [h@smsmtrx:1] NoOp("DAHDI/4-1", "Hanging up - SMS call failed") in new stack -- Executing [h@smsmtrx:2] Hangup("DAHDI/4-1", "") in new stack == Spawn extension (smsmtrx, h, 2) exited non-zero on 'DAHDI/4-1' -- Hungup 'DAHDI/4-1' AsteriskSMS*CLI>

Could anyone please shed some light as to what I’m doing wrong? I’ve Googled but found nothing of help and searching these forums is yielding no clues. Has anyone got Asterisk and fixed line SMS working with the BT Text service at all???

Any help anyone can give would be great - hoping someone knows something!!!

Cheers,

Jim

The modem implementation in Asterisk is poor. It tries to use logic that is appropriate for call progress tones, but will not work well for tones that only about 1 and a bit cycles long. That could well explain why it is failing to see the mark state at the end of the character, the stop bit, properly.

There is an issue about the quality of the modem, but it needs someone with DSP knowledge and a desire to get it working.