Hello, In my follwing setup Sipml5 -> FS -> Cisco ->PSTN the codec is changed during the call. At the first glance the call evolution is: 1. Sipml5 Client codec pref is OPUS,ISAC, PCMU, PCMA , Cisco voice class codec PCMU, PCMA (g711u&a). After negociation the PCMU codec is set. 2014-08-25 19:03:05.412802 [DEBUG] switch_core_media.c:3475 Audio Codec Compare [PCMU:0:8000:20:64000:1]/[PCMU:0:8000:20:64000:1] 2014-08-25 19:03:05.412802 [DEBUG] switch_core_media.c:3530 Audio Codec Compare [PCMU:0:8000:20:64000:1] ++++ is saved as a match The call is set up, voice goes well in both ways. 2. After a while(after receiving the next SDP packet from WebRtc Client) it seems that it finds a new codec match in OPUS. 2014-08-25 19:04:11.292795 [DEBUG] switch_core_media.c:3475 Audio Codec Compare [opus:111:48000:60:0:1]/[opus:116:48000:20:0:1] 2014-08-25 19:04:11.292795 [DEBUG] switch_core_media.c:3530 Audio Codec Compare [opus:116:48000:20:0:1] ++++ is saved as a match FS will change the codec and the call will end. 2014-08-25 19:04:11.292795 [DEBUG] switch_core_media.c:2260 Changing Codec from PCMU@20ms@8000hz to opus@20ms@48000hz 2014-08-25 19:04:11.332798 [DEBUG] switch_core_media.c:2352 Set Codec sofia/internal/xxxx@5.6.7.8 opus/48000 20 ms 960 samples 0 bits 1 channels 2014-08-25 19:04:11.332798 [DEBUG] switch_core_codec.c:123 sofia/internal/ xxxx@5.6.7.8 Original read codec replaced with opus:116 2014-08-25 19:04:11.352807 [NOTICE] switch_core_io.c:1257 Activating write resampler 2014-08-25 19:04:11.752801 [NOTICE] switch_rtp.c:1144 Auto Changing stun/rtp/dtls port from 1.2.3.4:50594 to 1.2.3.4:19602 2014-08-25 19:04:12.072801 [ERR] mod_opus.c:402 Decoder Error: corrupted stream! 2014-08-25 19:04:12.072801 [ERR] switch_core_io.c:1310 Codec OPUS (STANDARD) decoder error! 2014-08-25 19:04:12.072801 [DEBUG] switch_ivr_bridge.c:579 sofia/external/ 5555555@9.9.9.9 ending bridge by request from write function I tried to force codec on both legs by adding: <action application="set" data="absolute_codec_string=PCMU,PCMA"/> but nothing change. Also inbound-late-negotiation is set to true in sofia-profiles. Any ideea how to fix this issue? Here is the full log: http://pastebin.freeswitch.org/23161 Thank you