Hi, I have a rarely error where I get this failure message in the log file. I am bit wondering because this is suposed to be a normal voice call and not a fax. Best regards, Paul. fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 2018-08-20 14:04:54.056776 [INFO] switch_ivr_originate.c:1215 Sending early media fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 2018-08-20 14:04:54.056776 [ERR] mod_sofia.c:2343 CODEC NEGOTIATION ERROR. SDP: fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 v=0^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 o=- 20012711 20012711 IN IP4 217.0.15.67^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 s=on transit^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 c=IN IP4 X.X.X.X^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 t=0 0^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 m=audio 13274 RTP/AVP 8 118 126 101^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 a=rtpmap:8 PCMA/8000^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 a=rtpmap:118 PCMA/8000^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 a=rtpmap:126 CLEARMODE/8000^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 a=rtpmap:101 telephone-event/8000^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 a=fmtp:101 0-15^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 a=gpmd:118 vbd=yes^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 a=ptime:20^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 m=image 11232 udptl t38^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 a=T38FaxVersion:0^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 a=T38MaxBitRate:14400^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 a=T38FaxMaxBuffer:3000^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 a=T38FaxMaxDatagram:500^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 a=T38FaxRateManagement:transferredTCF^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 a=T38FaxUdpEC:t38UDPRedundancy^M fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 fe3eed7c-e03a-40af-bc2e-ae0bfe54bb28 2018-08-20 14:04:54.056776 [NOTICE] switch_channel.c:3515 Hangup sofia/external/+ 49XXXXXXXXX@sip-trunk.telekom.de [CS_EXECUTE] [INCOMPATIBLE_DESTINATION]