[Serusers] Rewriting SDP Infos for NAT Traversal

[Greger V. Teigre]

Depends on your SIP Server. You say nothing about it. Is it SER? Something 
else? You need to route all messages to SER Proxy to make sure that things 
go through a NAT. Is this to get rid of the NAT problem that "SIP Server" 
cannot do?
g-)
----- Original Message ----- 
From: "Anthony Chapellier" <anthony at mbdsys.com>
To: "Greger V. Teigre" <greger at teigre.com>; <serusers at lists.iptel.org>
Sent: Thursday, November 10, 2005 12:54 PM
Subject: Re: [Serusers] Rewriting SDP Infos for NAT Traversal


>I saw the config files examples and adapted one of them with my own 
>configuration because I need to use SER Proxy as a simple proxy which 
>support NAT traversal... To process REGISTER requests or INVITE requests, I 
>got a SIP¨Server on another entity.
>
> The scheme for my problem is the following :
>
> UAC 1 ------ \
>                        \
>                         |------- NAT ---- SER Proxy ---- SIP Server
>                        /
> UAC 2 ------ /
>
> REGISTER requests from UAC1 and UAC2 are processing correctly to SIP 
> Serever via SER Proxy. But when I'm trying to do a call from UAC1 to UAC2, 
> things are going bad.
>
> Indeed, the first INVITE request from UAC1 is going to SIP Server via SER 
> Proxy but when SIP Server process the INVITE request, he's trying to 
> forward the INVITE Request directly to UAC2 without passing by SER 
> Proxy...
>
> The result is NAT don't allow INVITE request to go to UAC2 and the call 
> can't be done.
>
> So, is there a way to force my SIP Server to do the INVITE request to UAC2 
> via SER Proxy ? by doing a different REGISTER request or INVITE request ?
>
> Thanks,
>
> Greger V. Teigre a écrit :
>
>> Anthony,
>> If the only thing you want to do, is NAT traversal, then that's been done 
>> before.  Have a look at http://onsip.org/ The Getting Started document 
>> and config files explains how to do NAT traversal with rtpproxy and 
>> mediaproxy.
>> g-)
>> ----- Original Message ----- From: "Anthony Chapellier" 
>> <anthony at mbdsys.com>
>> To: <serusers at lists.iptel.org>
>> Sent: Wednesday, November 09, 2005 3:38 PM
>> Subject: [Serusers] Rewriting SDP Infos for NAT Traversal
>>
>>
>>> Hi,
>>>
>>> When an INVITE request is incoming, I need to rewrite VIA Header Field, 
>>> Contact Header Field, (c=) field in SDP message core and (o=) field in 
>>> SDP message core too with IP public adress of UAC. Those are needed by 
>>> my SIP Server before SER Proxy forward the request to him.
>>>
>>> I got some success with rewriting Contact Header File by using 
>>> fix_nated_contact() function and (c=) field with fix_nated_sdp("1") 
>>> function. But I don't succeed at all in rewriting (o=) field and 
>>> partially for VIA Header Field.
>>>
>>> To do so, I tried to use the following function  :
>>>
>>> fix_nated_sdp("8");       No Result :(
>>> forcerport();                  It seems to add real IP public adress and 
>>> port in VIA header field but it's 
>>> not rewriting IP private adress
>>>
>>> So, finally is it the good way to do this thing or is there something 
>>> wrong with my behaviour ?
>>>
>>> Thanks,
>>>
>>>
>>>
>>> _______________________________________________
>>> Serusers mailing list
>>> serusers at lists.iptel.org
>>> http://lists.iptel.org/mailman/listinfo/serusers
>>>
>>>
>>
>>
>>
>>
>>
>
>
> -- 
> M. Anthony Chapellier
> ---------
> MBDSYS SARL
> 139, avenue Paul Vaillant Couturier
> 93120 LA COURNEUVE
> FRANCE
>
> Tel : +33 (0) 148 35 20 46
> Fax : +33 (0) 148 37 79 28
>
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>
>