[Users] x-lite and nat_uac_test(16)

[Klaus Darilion]

This looks indeed strange. Are you using the newest version of xlite?

Maybe the client tries STUN too and gets this port from a STUN lookup. 
Is stun disabled/enabled? What are the settings on the "Topology" card 
(STUN, IP address, X-tunnels)?

regards
klaus

Alexander Bergolth wrote:
> Hi!
> 
> On 05/21/2007 04:30 PM, Klaus Darilion wrote:
>> For SIP capture please use "ngrep -W byline port 5060" which is much
>> more readable. (or post the .cap file to open it in wireshark)
> 
> OK. Didn't know that ngrep is also available for Windows.
> The pcap file is now available at http://leo.kloburg.at/tmp/x-lite/.
> 
>> IIRC xlite/eyebeam always puts the local socket into the Via header.
> 
> What do you mean by "local socket"?
> TDImon shows that xlite binds (listens) to the port that is announced by
> the Via header but it doesn't send any packet from that port.
> 
>> But this should be no problem as rport parameter is used.
> 
> Yes, xlite adds an rport parameter but the wrong port number
> nevertheless confuses nat_uac_test(16). openser thinks that NAT mapping
> is involved and always activates rtpproxy although maybe the client has
> full internet connectivity.
> 
> Of course I could disable nat_uac_test(16) and only use nat_uac_test(3)
> but I don't think that this is the intended behavior.
> 
>> Further, the Contact: header will be the public socket (learned by
>> rport/received from Viaheader of 200 Ok).
> 
> The Contact header sent by the server in the OK-message contains three
> port numbers:
> 
> - 6276 which I couldn't find in any packet before (?)
> - 21744, the "wrong" port number which is also found in the initial
> Via-header
> - 2752 (the correct source port) in the received parameter
> 
> -------------------- 8< --------------------
> Contact:
> <sip:30001 at 137.208.90.164:6276;rinstance=b834d8b3a5111f02;transport=TCP>;expires=150,
> <sip:30001 at 137.208.90.164:21744;rinstance=8f61071c78d28a71;transport=TCP>;expires=3600;received="sip:137.208.90.164:2752;transport=TCP"
> -------------------- 8< --------------------
> 
> Cheers,
> --leo
> 
>> Thus, xlite does SIP NAT traversal for TCP itself.
>>
>> regards
>> klaus
>>
>> Alexander Bergolth wrote:
>>> On 05/21/2007 03:15 PM, Andreas Granig wrote:
>>>> Can you provide a full trace of the complete X-Lite startup sequence
>>>> from the host where X-Lite is running? Maybe there's some STUN stuff
>>>> going on prior to the registration (don't know exactly how this works,
>>>> but it'll show up in the trace).
>>> Stun-stuff is turned off and doesn't show up in the trace.
>>> An x-lite trace and the corresponding wireshark output is available at
>>>
>>> http://leo.kloburg.at/tmp/x-lite/
>>>
>>> The source-port used by the tcp-connection is 2752, the Via-header
>>> states 21744.
>>>
>>> Cheers,
>>> --leo
>>>
>>>> Alexander Bergolth wrote:
>>>>> On 05/18/2007 05:21 PM, Andreas Granig wrote:
>>>>>> Alexander,
>>>>>>> I've noticed that (at least on my boxes) x-lite uses a different
>>>>>>> source-port for the sip-connection than the one that is announced in
>>>>>>> the
>>>>>>> Via-header. (See the example below.)
>>>>>> Are you sure there isn't any NAT or ALG in between? By default, x-lite
>>>>>> binds to local port 5060, but you've some non-standard ports in there.
>>>>>> So my guess is either a non-standard port setting in x-lite and
>>>>>> NAT, or
>>>>>> a faulty ALG on the NAT device.
>>>>>>
>>>>>> Here's a trace using x-lite 2.0 r1105d (Linux):
>>>>>>
>>>>>> U 192.168.123.129:5060 -> <public IP>:5060
>>>>>> REGISTER sip:<some domain> SIP/2.0.
>>>>>> Via: SIP/2.0/UDP 192.168.123.129:5060;rport;branch=z9hG4<snip>
>>>>> I did some further tests using X-Lite for Windows with interesting
>>>>> results:
>>>>>
>>>>> TCP enabled:
>>>>>
>>>>> - X-Lite binds to a source-port different from 5060 although 5060 is
>>>>> available according to netstat.
>>>>>
>>>>> - the port that shows up in the Via-header is different from the
>>>>> source-port that is used for the TCP-connection
>>>>>
>>>>> only UDP enabled on the server:
>>>>>
>>>>> - X-Lite binds to a source-port different from 5060 although 5060 is
>>>>> available according to netstat.
>>>>>
>>>>> - the port that shows up in the Via-header is the correct source-port
>>>>>
>>>>> - if there is a TCP-SRV record in DNS, it tries TCP first, falls
>>>>> back to
>>>>> UDP after 19 seconds but uses "Via: SIP/2.0/TCP" instead of "Via:
>>>>> SIP/2.0/UDP"
>>>>>
>>>>> I'll file a bug-report, let's see what happens...
>>>>>
>>>>> Cheers,
>>>>> --leo
>>>
> 
>