Hello. We are facing the following problem with our FS setup: 1. provider sends us INVITE with "a=sendonly" in SDP 2. FS picks up the call, playing ivr and replying with 200 and "a=recvonly" in SDP 3. provider sends Re-INVITE without SDP 4. FS replying 200 with already negotiated SDP (single codec and "a=recvonly") Provider wants renegotiation of sdp on step 4, or a least "a=sendrecv" parameter. Is there a way to achieve this without source modification? We tried setting following profile parameters: renegotiate-codec-on-hold=true renegotiate-codec-on-reinvite=true enable-3pcc=true but no luck. The only solution we found was modifing sofia.c like this: line 7374 - replace switch_core_media_gen_local_sdp(session, SDP_TYPE_RESPONSE, NULL, 0, NULL, 0); with switch_core_media_gen_local_sdp(session, SDP_TYPE_RESPONSE, NULL, 0, "sendrecv", 0); line 7376 - replace nua_respond(tech_pvt->nh, SIP_200_OK, TAG_END()); with nua_respond(tech_pvt->nh, SIP_200_OK, SOATAG_USER_SDP_STR(tech_pvt->mparams.local_sdp_str), TAG_END()); Thanks.