<div dir="ltr">Very interesting thing going on between opensips and my client [UA]<div><br></div><div>Opensips sending following contact header to Client but on client side i check it received different contact header, who is changing it?</div><div><br></div><div>[UA]-----[Opensips]------[FS]</div><div><br></div><div>UA - 173.xx.xx.xx.215</div><div>Opensips - 182.xx.xx.164:5060</div><div>FS - 182.xx.xx.162:5061</div><div><br></div><div>My UA behind the NAT and I have ALG disabled on router. </div><div><br></div><div><br></div><div>* [Opensips] sending following packet SDP OK 200 to [UA]</div><div><br></div><div><div><span style="font-size:12.8000001907349px">2015/04/08 07:42:22.820354 182.xx.xx.164:5060 -&gt; 173.xx.xx.215:49152</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px">SIP/2.0 200 OK</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px">Via: SIP/2.0/UDP 173.xx.xx.215:49152;received=</span><span style="font-size:12.8000001907349px">173.xx.xx.215;rport=49152;</span><span style="font-size:12.8000001907349px">branch=z9hG4bKPjHB6245E6-</span><span style="font-size:12.8000001907349px">SpIsEUs.kPIxxNAFMM0HTDo</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px">Record-Route: &lt;sip:182.xx.xx.164;lr;ftag=</span><span style="font-size:12.8000001907349px">OdSDiepaL9YssVLqOv.</span><span style="font-size:12.8000001907349px">3C82QrrsrrdUV;did=3fd.</span><span style="font-size:12.8000001907349px">556edf93&gt;</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px">CSeq: 722 INVITE</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px">Contact: &lt;sip:1646327XXXX@182.xx.xx.162</span><span style="font-size:12.8000001907349px">:5061;transport=udp&gt;</span><br></div></div><div><br></div><div><br></div><div><br></div><div>* [UA] Received following packet, look at Contact:  it changed here. 162 to 164.  </div><div><br></div><div><span style="font-size:12.8000001907349px">U 182.xx.xx.164:5060 -&gt; </span><a href="http://192.168.1.9:60895/" target="_blank" style="font-size:12.8000001907349px">192.168.1.9:60895</a><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px">IP/2.0 200 OK.</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px">Via: SIP/2.0/UDP 173.xx.xx.215:49152;received=</span><span style="font-size:12.8000001907349px">192.168.1.9;rport=49152;</span><span style="font-size:12.8000001907349px">branch=z9hG4bKPjHB6245E6-</span><span style="font-size:12.8000001907349px">SpIsEUs.kPIxxNAFMM0HTDo.</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px">Record-Route: &lt;sip:182.xx.xx.164:5060;lr;</span><span style="font-size:12.8000001907349px">ftag=OdSDiepaL9YssVLqOv.</span><span style="font-size:12.8000001907349px">3C82QrrsrrdUV;did=3fd.</span><span style="font-size:12.8000001907349px">556edf93&gt;.</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px">CSeq: 722 INVITE.</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px">Contact: &lt;sip:1646327XXXX@182.xx.xx.164</span><span style="font-size:12.8000001907349px">:5061;transport=udp&gt;.</span><br></div></div>