Dear All, I am trying to figure out why I see what I see. When I make a call using the same codec (say, PCMA/8000 on both sides), FreeSwitch rewrites the RTP stream's IP address and port for me. That I like, since my FreeSwitch is behind NAT. From the logs: 2014-07-16 12:32:36.815907 [INFO] switch_rtp.c:3738 Auto Changing port from 1.2.3.4:4040 to 5.6.7.8:4040 2014-07-16 12:32:36.995906 [INFO] switch_rtp.c:3738 Auto Changing port from 9.10.11.12:12345 to 13.14.15.16:41730 Now, when I try to use two different codecs, this behaviour stops. From the logs and without changing the configuration or restarting FreeSwitch: 2014-07-16 12:35:36.495902 [INFO] switch_rtp.c:3738 Auto Changing port from 1.2.3.4:4042 to 5.6.7.8:4042 The other line is missing and ngrep reveals how FreeSwitch stubbornly sends RTP audio to the wrong port and IP address. Further testing shows: PCMA -> PCMA: IP/port is rewritten SILK -> PCMA: IP/port is *not* rewritten GSM -> PCMA: IP/port is rewritten Speex -> PCMA: IP/port is *not* rewritten How can I have transcoding *and* RTP IP/port rewriting work at the same time, please? Is this a per-codec thing? -- Kees Jan http://java-monitor.com/ kjkoster@kjkoster.org +31651838192 Change is good. Granted, it is good in retrospect, but change is good.