> I'm testing a SIP trunk to Covista Communications. I'm able > to receive and send calls but there's two catches: > > 1. Placing a call from internal to my cell phone, I do not > hear ring tones but the cell phone will ring and caller ID is > shown properly. If I answer the cell I do not hear any audio > in either direction however according to captures and the > phones the call is connected. > > 2. Inbound calls (cell phone to internal) I hear a ring tone > and also see correct caller ID but there's still no audio > after answering. Again, all appears normal on captures and the phones. > > RTP captures are showing a difference in codecs. G.711 on > outbound, example: > > 22.588943 172.16.1.200 -> 172.16.1.2 RTP PT=ITU-T G.711 > PCMU, SSRC=0x94955FF, Seq=27757, Time=688410696 > > and G.729 inbound, example: > > 6.758089 172.16.1.200 -> 172.16.1.2 RTP PT=ITU-T G.729, > SSRC=0x3CA4274A, Seq=25643, Time=1257971077 > > Could this be the problem?
This could very well be the problem if the SIP phone you use does not support asymmetric codecs nor does the lock-down procedure described in Section 10.2 of RFC3264. To prove it, reconfigure your phone's audio/rtp preferences to only use G.729. This will eliminate the possibility of codec asymmetry - if the call now works, you have your answer. bob _______________________________________________ sipx-users mailing list [email protected] List Archive: http://list.sipfoundry.org/archive/sipx-users Unsubscribe: http://list.sipfoundry.org/mailman/listinfo/sipx-users sipXecs IP PBX -- http://www.sipfoundry.org/
