[OpenSER-Users] port modification is sdp

[Konstantinos Koutsopoulos]

Hi,

first of all to correct the message below

(with openser and client B) should be (with openser and client A).


I have checked again with tshark on the openser's interface
and it seems that indeed my adsl router intervene with my SDP.
Thanks for the hints and sorry for the inaccuracies.

Regards,

Kostas


Iñaki Baz Castillo wrote:
> El Wednesday 31 October 2007 10:22:05 Konstantinos Koutsopoulos escribió:
>   
>>  The NATted device (client B) is behind a USR 9112,
>>  the other machine (with openser and client B) is on an
>>  academic LAN. The fact, however, is that tshark indicates
>>  that the original sdp (from B) reaches port 5060 of openser
>>  but the invite that is thereafter forwarded to client A
>>  contains a modified sdp.
>>     
>
> Not sure if I've understood, you said always "client B" XD
>
> I assume client B calls from NAT. Is it a softphone?
> Could you try with a softphone as B and do a ngrep o tshark in the **same** 
> machine B is running and notate the INVITE message?
>
> Then you can do a ngrep in OpenSer and inspect the received INVITE form B.
>
> If the NAT has been fixed "by magic" then your router (in B LAN) does ALG's, 
> so it rewrites the SIP message and replaces private IP with public IP and 
> internal ports with NAT mapped external ports.
>
>
>
>
>