Hi, Am Dienstag, den 05.01.2010, 15:38 +0100 schrieb Christian Theune: > Hi, > > I tried again getting DTMF detection on my ISDN devices with dahdi going > again. I used the channel debug to see whether asterisk sees the frames > and detects them as DTMF. > > Interestingly here's what works: > > 1. GSM phone -> chan_dahdi g1 -> asterisk -> can_sip -> SIP phone > > Both the GSM phone and the SIP phone can issue DTMF that will be > detected as features (transfer) > > 2. GSM phone -> chan_dahdi g1 -> asterisk -> chan_dahdi g4 -> ISDN phone > > The GSM phone can issue DTMF that will be detected. The ISDN phone > won't. (That's my issue.) I don't see any messages of asterisk > recognizing the DTMF frames when pressing the keys. I do hear the DMTF > sound on both phones. > > 3. ISDN phone -> chan_dahdi g4 -> asterisk -> chan_dahdi g1 -> GSM phone > > The ISDN phone can issue DTMF that will be recognized and so does the > GSM phone. > > So. When the ISDN phone is receiving a call on g4 its DTMF sounds won't > be recognized. OTOH when the GSM phone on g1 is being called it's sounds > are recognized.
I *think* there are two possibilities to transfer DTMF on ISDN: - as audio on B-Channel - as Key-Press events (Info-Elements) on D-Channel DTMF on GSM can not be signalled as audio (because of codec with high compression). I guess in case GSM => asterisk via "chan_dahdi g1" in Your example, the DTMF is signalled as Info-Elements on D-Channel. I guess in the cases where Your DTMF is not working, audio path is used. In this case DTMF detection is done by DSP-Software. Look for the relaxdtmf statement (in case of zaptel this worked for me in a simmilar scenario). HTH, Karsten _______________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
