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<tt>You can check it in the pcap - if an UDP packet is fragmented into
multiple IP packets, you have some fragmentation flag set into the
IP header (see
<a class="moz-txt-link-freetext" href="https://www.cs.nyu.edu/courses/fall98/G22.2262-001/class11.txt">https://www.cs.nyu.edu/courses/fall98/G22.2262-001/class11.txt</a>,
look for "fragmentation" ).<br>
<br>
Also, at SIP level, you may check if the advertised Content-Length
matches the actual length of the body - if the body is shorter
than advertised in Content-Len, it means the UDP packet is
fragmented . <br>
<br>
Regards,<br>
</tt>
<pre class="moz-signature" cols="72">Bogdan-Andrei Iancu
OpenSIPS Founder and Developer
<a class="moz-txt-link-freetext" href="http://www.opensips-solutions.com">http://www.opensips-solutions.com</a></pre>
<div class="moz-cite-prefix">On 06.05.2016 20:11, Nabeel wrote:<br>
</div>
<blockquote
cite="mid:CA+vx6KKF9xC+6QD5LUDGrGuKXUbzBgobBVmhhKxsRABFhpcxBQ@mail.gmail.com"
type="cite">
<p dir="ltr">Can packet fragmentation be verified (to be sure that
it is packet fragmentation)? </p>
<div class="gmail_quote">On 6 May 2016 5:28 pm, "Nabeel" <<a
moz-do-not-send="true" href="mailto:nabeelshikder@gmail.com"><a class="moz-txt-link-abbreviated" href="mailto:nabeelshikder@gmail.com">nabeelshikder@gmail.com</a></a>>
wrote:<br type="attribution">
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<p dir="ltr">The trace I posted earlier is what I see with
tcpdump when attempting a call. There is no other INVITE
shown in the trace: <a moz-do-not-send="true"
href="http://pastebin.com/raw/C4iymTbh" target="_blank">http://pastebin.com/raw/C4iymTbh</a></p>
<p dir="ltr">The trace seems to end abruptly in the middle of
the SDP, so I think it could be due to packet fragmentation.
</p>
<div class="gmail_quote">On 6 May 2016 4:18 pm, "Bogdan-Andrei
Iancu" <<a moz-do-not-send="true"
href="mailto:bogdan@opensips.org" target="_blank">bogdan@opensips.org</a>>
wrote:<br type="attribution">
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000"> <tt>So that meas
the INVITE never gets to the callee ?? maybe it is not
properly routed . <br>
<br>
Do you see (with ngrep or tcpdump) the INVITE being
sent out by opensips towards callee ?<br>
<br>
Regards,<br>
</tt>
<pre cols="72">Bogdan-Andrei Iancu
OpenSIPS Founder and Developer
<a moz-do-not-send="true" href="http://www.opensips-solutions.com" target="_blank">http://www.opensips-solutions.com</a></pre>
<div>On 06.05.2016 12:56, Nabeel wrote:<br>
</div>
<blockquote type="cite">
<p dir="ltr">Hi,</p>
<p dir="ltr">Thanks for the idea about packet
compression. By 'call fails to connect', I meant the
call does not connect to the callee, ie. the
callee's phone does not ring after the INVITE
(despite using TURN server). </p>
<p dir="ltr">This was a public WiFi network and that
was all I could get at the time. I am using OpenSIPS
version 2.1.</p>
<p dir="ltr">Nabeel</p>
<div class="gmail_quote">On 6 May 2016 9:16 am,
"Bogdan-Andrei Iancu" <<a moz-do-not-send="true"
href="mailto:bogdan@opensips.org" target="_blank">bogdan@opensips.org</a>>
wrote:<br type="attribution">
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000"> <tt>Hi,<br>
<br>
Hard to analyze a call based on the INVITE
packet only :). Still the SIP signaling does
not show any ALG interference (also not sure
if the capture was done before or after the
ALG). Also, what you mean by "call fails" ?no
reply, negative reply , no audio ?<br>
<br>
Regards,<br>
</tt>
<pre cols="72">Bogdan-Andrei Iancu
OpenSIPS Founder and Developer
<a moz-do-not-send="true" href="http://www.opensips-solutions.com" target="_blank">http://www.opensips-solutions.com</a></pre>
<div>On 05.05.2016 22:35, Nabeel wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div class="gmail_extra"><br>
</div>
<div class="gmail_extra">Please check the
following SIP trace taken within a WiFi
network. The call fails to connect despite
the INVITE request and using a
non-standard port. Could this be caused by
SIP ALG, or some unopened RTP port on the
router?</div>
<div class="gmail_extra"><br>
</div>
<div class="gmail_extra"><a
moz-do-not-send="true"
href="http://pastebin.com/raw/C4iymTbh"
target="_blank"><a class="moz-txt-link-freetext" href="http://pastebin.com/raw/C4iymTbh">http://pastebin.com/raw/C4iymTbh</a></a><br>
</div>
</div>
<br>
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