I'm using Freeswitch as a PBX for OpenBTS, to route calls from mobile phones to VoIP providers.
When bridging a call from a cellular handset to a mod_skypopen interface, I get the following error as soon as the Skype call is answered. The handset then hangs up. It appears the problem lies in the 'audio codec compare' phase.
2013-10-16 17:54:21.932473 [DEBUG] switch_channel.c:3548 Send signal sofia/internal/IMSI[me]@[ip] [BREAK]
2013-10-16 17:54:21.932473 [NOTICE] mod_skypopen.c:2471 Channel [skypopen/skype101/echo123] has been answered
2013-10-16 17:54:21.932473 [DEBUG] switch_channel.c:3594 (skypopen/skype101/echo123) Callstate Change RINGING -> ACTIVE
2013-10-16 17:54:21.932473 [DEBUG] mod_skypopen.c:1232 [543dc3c|22dd4bf] [DEBUG_SKYPE 1232 ][skype101 ][UP,INPROGRS] MSG_ID=41
2013-10-16 17:54:21.932473 [DEBUG] mod_skypopen.c:2479 [543dc3c|22dd4bf] [DEBUG_SKYPE 2479 ][skype101 ][UP,INPROGRS] outbound_channel_answered!
2013-10-16 17:54:21.932473 [DEBUG] skypopen_protocol.c:1172 [543dc3c|22dd4bf] [DEBUG_SKYPE 1172 ][skype101 ][UP,INPROGRS] ACCEPTED here you send me 32776
2013-10-16 17:54:21.932473 [DEBUG] skypopen_protocol.c:1177 [543dc3c|22dd4bf] [DEBUG_SKYPE 1177 ][skype101 ][UP,INPROGRS] 4 SO_RCVBUF is 5120, size is 4
2013-10-16 17:54:21.932473 [DEBUG] skypopen_protocol.c:1181 [543dc3c|22dd4bf] [DEBUG_SKYPE 1181 ][skype101 ][UP,INPROGRS] 4 SO_SNDBUF is 5120, size is 4
2013-10-16 17:54:21.952511 [DEBUG] skypopen_protocol.c:207 [543dc3c|22dd4bf] [DEBUG_SKYPE 207 ][skype101 ][UP,INPROGRS] READING: |||ALTER CALL 32 SET_INPUT PORT="32776"|||
2013-10-16 17:54:21.952511 [DEBUG] sofia_glue.c:5226 Audio Codec Compare [GSM:3:8000:20:13200]/[PCMU:0:8000:20:64000]
2013-10-16 17:54:21.952511 [DEBUG] sofia_glue.c:5226 Audio Codec Compare [GSM:3:8000:20:13200]/[PCMA:8:8000:20:64000]
2013-10-16 17:54:21.952511 [DEBUG] sofia_glue.c:5370 No 2833 in SDP. Disable 2833 dtmf and switch to INFO
2013-10-16 17:54:21.952511 [DEBUG] switch_core_session.c:858 Send signal sofia/internal/IMSI[me]@[ip] [BREAK]
2013-10-16 17:54:21.952511 [NOTICE] switch_channel.c:3633 Hangup sofia/internal/IMSI[me]@[ip] [CS_EXECUTE] [INCOMPATIBLE_DESTINATION]
Any advice on forcing a transcode or otherwise having the Audio Codec Compare result in a successful bridge is appreciated.