If anyone sees any mistakes in the following advice, please let me know. I recently went through a bit of a configuration nightmare with the Cisco 7905 phone using the g729 codec and Asterisk and I thought I share it here for anyone who might be searching for help on this in the future.
The setup is three, 7905 Cisco phones with the SIP firmware attached to a Asterisk server remotely through a NAT firewall. The Asterisk is connecting to the PSTN via a SIP gateway (a Mediatrix box) which only uses g711. This setup was actually fairly easy but the one nagging problem was the DTMF tones. We tried numerous configurations with different results. Sometimes DTMF tones would work on outbound calls but not on the Asterisk voice mail system. Other times they would work for voicemail but no tone would be heard on the outside call. Even more frustrating, sometimes we could get DTMF if the call was placed outbound, but incoming calls had no DTMF. Anyhow, here is what I learned. 1. When using a Cisco phone with the g729 codec, your sip.conf should be as follows (simplified): [XXXXXXX] type=friend context=local username=XXXXXXX callerid=XXXXXXX secret=XXXXXXX host=dynamic mailbox=XXXXXXX nat=yes qualify=yes dtmfmode=rfc2833 ; * See note. canreinvite=no disallow=all allow=g729 * Note: If you use g729 you can not use "inband". Documentation on the voip-wiki seems to indicate that you should use "dtmfmode=info" with the Cisco phone but I found this does NOT work end-to-end with outbound, inbound, and voicemail system. The settings on the Cisco phone are also very important. They should be: RxCodec:3 ;g729 TxCodec:3 ;g729 AudioMode :0x00000020 ; DTMF signalling Always out-of-band * Note: remember you have to buy g729 licenses for Asterisk from digium. On the flip side, the gateway is set as follows: [mediatrix] type=peer context=mediatrix host=xxx.xxx.xxx.xxx dtmfmode=inband ; inband works with g711 only disallow=all allow=ulaw allow=alaw I hope this helps someone. -- John Lange _______________________________________________ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users