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<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black">Hi, I have “30
second-then-hangup” problem. I have traced the problem, and turn out that the server
keeps sending ACK to SIP Client local IP Address (it is behind the NAT). </span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"> </span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black">Is it a misconfigure
in FS? I notice that in SDP received from SIP Client the rtcp port is followed
by SIP Client local IP address. Is it right or not?</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"> </span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black">Here is the SIP
trace result:</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"> </span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"> </span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black">recv 738 bytes
from udp/[118.xxx.xxx.xxx]:6900 at 10:21:33.992037:</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>  
</span>------------------------------------------------------------------------</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>SIP/2.0 200 OK</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>Via: SIP/2.0/UDP
192.168.1.150:57699;rport=57699;branch=z9hG4bK4Q9KyFrDr24gc</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>From: &quot;400001&quot; &lt;sip:400001@180.xxx.xxx.xxx&gt;;tag=59etrFg3F0pvg</span></p>


<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>To: &lt;sip:400002@118.xxx.xxx.xxx:6900;line=b1bb925d6ab814e&gt;;tag=189404928</span></p>


<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>Call-ID: ea145392-ddb9-1231-9c95-94de80208578</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>CSeq: 53085761 INVITE</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>Contact:
&lt;<a href="http://sip:linphone.android@192.168.8.47:6900">sip:linphone.android@192.168.8.47:6900</a>&gt;</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>Content-Type: application/sdp</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>User-Agent: LinphoneAndroid/0.3.7
(eXosip2/3.6.0)</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>Content-Length:<span style>   </span>260</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span></span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>v=0</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>o=400002 1335 3400 IN IP4 118.xxx.xxx.xxx</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>s=Talk</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>c=IN IP4 118.xxx.xxx.xxx</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>b=AS:380</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>t=0 0</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>m=audio 7078 RTP/AVP 98 101</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>a=rtpmap:98 speex/8000</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>a=fmtp:98 vbr=on</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>a=rtpmap:101 telephone-event/8000</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>a=fmtp:101 0-11</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>a=rtcp:7079 IN IP4 192.168.8.47</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>------------------------------------------------------------------------</span></p>


<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black">nta.c:3201
agent_recv_response() nta: received 200 OK for INVITE (53085761)</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black">nta.c:3264
agent_recv_response() nta: 200 OK is going to a transaction</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black">send 434 bytes to
udp/[192.168.8.47]:6900 at 10:21:33.992228:</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>  
</span>------------------------------------------------------------------------</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>ACK <a href="http://sip:linphone.android@192.168.8.47:6900">sip:linphone.android@192.168.8.47:6900</a>
SIP/2.0</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>Via: SIP/2.0/UDP 180.xxx.xxx.xxx:57699;rport;branch=z9hG4bK502c0a9gNBU3Q</span></p>


<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>Max-Forwards: 70</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>From: &quot;400001&quot; &lt;sip:400001@180.xxx.xxx.xxx&gt;;tag=59etrFg3F0pvg</span></p>


<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>To: &lt;sip:400002@118.xxx.xxx.xxx:6900;line=b1bb925d6ab814e&gt;;tag=189404928</span></p>


<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>Call-ID:
ea145392-ddb9-1231-9c95-94de80208578</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>CSeq: 53085761 ACK</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>Contact: &lt;sip:mod_sofia@180.xxx.xxx.xxx:57699&gt;</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span>Content-Length: 0</span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>   </span></span></p>

<p class="MsoNormal" style="text-autospace:none"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"><span style>  
</span>------------------------------------------------------------------------</span></p>

<p class="MsoNormal"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black">nta.c:8169 outgoing_send() nta: resent ACK
(53085761) to UDP/<a href="http://192.168.8.47:6900">192.168.8.47:6900</a></span></p>

<p class="MsoNormal"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"> </span></p>

<p class="MsoNormal"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black">Thanks,</span></p>

<p class="MsoNormal"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"> </span></p>

<p class="MsoNormal"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black">Regards</span></p>

<p class="MsoNormal"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black"> </span></p>

<p class="MsoNormal"><span style="font-size:8pt;font-family:&quot;Menlo Regular&quot;;color:black">Donny</span></p>





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