Hey, I tried to establish audio call between two clients having different codec supports . I expected that transcoding would take place. But I am getting a codec negotiation error . Here is the information about client I am using leg A : suppoerted codec : speex leg B: supported codec : G722,PCMU,PCMA,GSM,OPUS Here is some lines from my freeswitch logs 2013-10-22 10:31:12.795786 [INFO] switch_ivr_originate.c:1190 Sending early media 2013-10-22 10:31:12.795786 [DEBUG] switch_core_media.c:2880 Audio Codec Compare [speex:110:8000:20:0]/[G722:9:8000:20:64000] 2013-10-22 10:31:12.795786 [DEBUG] switch_core_media.c:2880 Audio Codec Compare [speex:110:8000:20:0]/[PCMU:0:8000:20:64000] 2013-10-22 10:31:12.795786 [DEBUG] switch_core_media.c:2880 Audio Codec Compare [speex:110:8000:20:0]/[PCMA:8:8000:20:64000] 2013-10-22 10:31:12.795786 [DEBUG] switch_core_media.c:2880 Audio Codec Compare [speex:110:8000:20:0]/[GSM:3:8000:20:13200] 2013-10-22 10:31:12.795786 [DEBUG] switch_core_media.c:3064 No 2833 in SDP. Disable 2833 dtmf and switch to INFO 2013-10-22 10:31:12.795786 [ERR] mod_sofia.c:2122 CODEC NEGOTIATION ERROR. SDP: v=0 o=Zoiper 0 0 IN IP4 120.63.38.94 s=Zoiper c=IN IP4 120.63.38.94 t=0 0 m=audio 11525 RTP/AVP 110 a=rtpmap:110 speex/8000 Here is some info about my freeswitch version - 1.4 beta codecs supported - codec,ADPCM (IMA),mod_spandsp codec,AMR,mod_amr codec,B64 (STANDARD),mod_b64 codec,G.711 alaw,CORE_PCM_MODULE codec,G.711 ulaw,CORE_PCM_MODULE codec,G.722,mod_spandsp codec,G.723.1 6.3k,mod_g723_1 codec,G.726 16k,mod_spandsp codec,G.726 16k (AAL2),mod_spandsp codec,G.726 24k,mod_spandsp codec,G.726 24k (AAL2),mod_spandsp codec,G.726 32k,mod_spandsp codec,G.726 32k (AAL2),mod_spandsp codec,G.726 40k,mod_spandsp codec,G.726 40k (AAL2),mod_spandsp codec,G.729,mod_g729 codec,GSM,mod_spandsp codec,H.261 Video (passthru),mod_h26x codec,H.263 Video (passthru),mod_h26x codec,H.263+ Video (passthru),mod_h26x codec,H.263++ Video (passthru),mod_h26x codec,H.264 Video (passthru),mod_h26x codec,LPC-10,mod_spandsp codec,PROXY PASS-THROUGH,CORE_PCM_MODULE codec,PROXY VIDEO PASS-THROUGH,CORE_PCM_MODULE codec,RAW Signed Linear (16 bit),CORE_PCM_MODULE codec,Speex,mod_speex codec,VP8 Video (passthru),mod_vp8 My sip_profile configurations <param name="disable-transcoding" value="false"/> <param name="inbound-late-negotiation" value="true"/> I also tried with inbound-late-negotiaion=false . But still getting codec negotiation error. Please help . Regards, Neeraj