[SR-Users] Kamailio, spiral with TM

[Klaus Darilion]

Am 08.07.2010 00:53, schrieb David:
> Hey,
>
> I do not do anything IP level forwarding. All my forwarding is done
> using Kamailio. It looks like what I am doing is called hairpin routing.

I think the correct term is "spiral" - at least the RFC uses this term.

How do you forward the request - t_relay()? If yes, then tm module 
should treat the request as a new transaction.

Post a trace (you can rewrite IP addresses):
ngrep -t -q -W byline -d any -P "" port 5060 or 5061

regards
Klaus

>
> Thanks,
>
> David
>
> On 2010-07-07 18:48, Timo Reimann wrote:
>> Hi,
>>
>>
>> David wrote:
>>> I have setup two Kamailio servers, my INVITEs will go through server A,
>>> which forwards to server B which forwards it back to server A.
>>>
>>> This is intential, the trouble is when the packet comes back through
>>> server B, nothing has changed so TM sees it as a retransmission.
>>>
>>> The difference between the first time through and the second time is the
>>> port 5061 instead of 5060.
>> If you forward the INVITE from B to A SIP-wise (e.g., by calling
>> forward()) a new Via header should be added which prevents the spiraled
>> INVITE message from being considered a retransmission on A.
>>
>> Do you perform forwarding on a lower level, like IP?
>>
>>
>> Cheers,
>>
>> --Timo
>
>
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