<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-9">
<META content="MSHTML 6.00.2900.2995" name=GENERATOR></HEAD>
<BODY>
<DIV dir=ltr align=left><SPAN class=953224608-09042007><FONT face=Arial
size=2>The client does not have STUN support. (I am not sure; because there is
no field to enter stun server address. However it may have an internal
STUN)</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=953224608-09042007><FONT face=Arial
size=2>Actually the client is the "internet calling" feature of new Windows
Mobile 6.0.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=953224608-09042007><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=953224608-09042007><FONT face=Arial size=2>I
am also nearly sure that there is no ALG in front of the UA. Plus, I am using
5061 on the SIP server as UDP port. So most of the ALG mechanisms do not mess
with my sip messages.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=953224608-09042007><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=953224608-09042007><FONT face=Arial size=2>I
believe this is a misconfiguration issue. But I don't know how to troubleshoot
it.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=953224608-09042007><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=953224608-09042007><FONT face=Arial
size=2>Any help on the nat configuration would be wonderful.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=953224608-09042007><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=953224608-09042007><FONT face=Arial
size=2>Thanks,</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=953224608-09042007><FONT face=Arial
size=2>ilker</FONT></SPAN></DIV><FONT face=Arial size=2></FONT><BR>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>From:</B> Greger Viken Teigre
[mailto:greger@teigre.com] <BR><B>Sent:</B> Monday, April 09, 2007 11:25
AM<BR><B>To:</B> İlker Aktuna (Koç.net)<BR><B>Cc:</B>
serusers@iptel.org<BR><B>Subject:</B> Re: [Serusers] interesting 2 way SIP
signalling problem<BR></FONT><BR></DIV>
<DIV></DIV>Most likely the invite is not detected as NATed by your config and
force_rport and fix_nated_contact (which will solve your problem) are not
called.<BR>If you use stun, it behaves badly. If not, you have an ALG in front
of the UA.<BR>g-)<BR><BR>------- Original message -------<BR>From: İlker Aktuna
(Koç.net) <ilkera@koc.net><BR>Sent: 9.4.'07, 9:32<BR><BR>>
Hi,<BR>> <BR>> I have a working configuration on my SER server. Most of
the users can make calls (both way incoming and outgoing) with no
problem.<BR>> However, I have some clients that can't make calls. <BR>>
When I analyze these by ngrep and/or tcpdump, I see that the SER server does not
reply the packet on the correct port.<BR>> <BR>> For example, I have a
testing client which is behind NAT.<BR>> The client sends INVITE message from
UDP port 3023 to port 5061 of my SER.<BR>> (cseq number is 1)<BR>> SER
exchanges the message with the uplink sip gateway and when it receives a "OK"
response it forwards this message to the client's NAT IP address BUT on a
different port (14640) with correct cseq number (1)<BR>> <BR>> Of course,
this new port is not open on the NAT router and it does not reach the
client.<BR>> <BR>> I see that the first INVITE message has Contact field
with internal IP address of the client and the port number as 14640.<BR>> So
the SER server sends the returning message to the external IP address with
internal port number.<BR>> <BR>> How can I fix this issue ?<BR>>
<BR>> I can send the configuration of my SER server if that would help to
find the problem.<BR></BODY></HTML>