Hi, Invoking force_rtp_proxy() after fix_nated_sdp() causes error that in the connection filed one ip address apears after second (previous one is not removed) v=0. o=- 3 2 IN IP4 192.168.1.3. s=CounterPath X-Lite 3.0. c=IN IP4 82.210.160.59192.168.129.74. t=0 0. m=audio 35036 RTP/AVP 107 119 100 106 0 105 98 8 101. a=fmtp:101 0-15. a=rtpmap:107 BV32/16000. a=rtpmap:119 BV32-FEC/16000. a=rtpmap:100 SPEEX/16000. a=rtpmap:106 SPEEX-FEC/16000. a=rtpmap:105 SPEEX-FEC/8000. a=rtpmap:98 iLBC/8000. a=rtpmap:101 telephone-event/8000. a=sendrecv. a=direction:active. a=oldmediaip:192.168.1.3. a=nortpproxy:yes. in the example above fix_nated_sdp put the 82.210.160.59 address and force_rtp_proxy instead of replacing the 82.210.160.59 appended it at the end of the line Cheers TOmasz