I have a problem with a provider where the call are dropped by Freeswitch after receiving a 183 + SDP. I think that the problem is in SDP but I don't know where. The SDP that Freeswitch sends in INVITE is: v=0 o=FreeSWITCH 1324273767 1324273768 IN IP4 62.196.58.2 s=FreeSWITCH c=IN IP4 62.196.58.2 t=0 0 m=audio 52062 RTP/AVP 18 101 13 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-16 a=ptime:20 where the SDP that Freeswitch receives from the provider is: v=0 o=sansay-VSX 10 10 IN IP4 206.172.44.229 s=session controller c=IN IP4 206.172.44.229 t=0 0 m=audio 28364 RTP/AVP 18 150 a=rtpmap:18 G729/8000 a=fmtp:18 annexb=no a=rtpmap:150 telephone-event/8000 a=fmtp:150 0-15 a=ptime:20 After this SDP I see in the log: 2011-12-19 21:17:11.567017 [DEBUG] switch_ivr_originate.c:3364 Originate Resulted in Error Cause: 100 [INVALID_IE_CONTENTS] Can anyone give me an advice to solve this issue? Stephen