I know this has been brought up previously in another thread, but wanted to mention I'm seeing it as well. However - I do have an additional data point. This is the SDP being sent: v=0 o=FreeSWITCH 1453729420 1453729421 IN IP4 131.151.x.x s=FreeSWITCH c=IN IP4 131.151.x.x t=0 0 m=audio 19222 RTP/AVP 102 103 9 0 8 104 106 101 a=rtpmap:102 G7221/32000 a=fmtp:102 bitrate=48000 a=rtpmap:103 G7221/16000 a=fmtp:103 bitrate=32000 a=rtpmap:9 G722/8000 a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:104 telephone-event/32000 a=fmtp:104 0-16 a=rtpmap:106 telephone-event/16000 a=fmtp:106 0-16 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-16 a=ptime:20 I realize that anything other than PCMU is pointless with flowroute. Symptom is seen on both 1.4 and 1.6. Confirming what some others on the thread have said - forcing codec to PCMU (in my case via carrier_gateway lcr table), immediately corrects the issue. It seems like a definite bug on flowroute's side, and will be following up with that on the open case. -- Nathan ------------------------------------------------------------ Nathan Neulinger nneul@mst.edu Missouri S&T Information Technology (573) 612-1412 System Administrator - Architect