[OpenSER-Users] port modification is sdp

[Bogdan-Andrei Iancu]

Hi Kostas,

With the configuration you sent it is impossible for openser to change 
the SDP - maybe you have some ALG that's doing that.....

regards,
bogdan

Konstantinos Koutsopoulos wrote:
> Hi Bogdan,
>
> exactly that is why I did not manage to explain, although I am 
> relatively new user to openser.
> I tried to locate documentation that explains this behaviour and I found 
> that no module
> performing such action is loaded and configured in my set-up. I have 
> just captured the
> packets to and form openser and saw that openser alters the sdp fields.
>
> Regards,
>
> Kostas
>
> Bogdan-Andrei Iancu wrote:
>   
>> Hi,
>>
>> But who is changing the IP and port in SDP? The script you sent makes 
>> no changes on the SDP part of the messages.
>>
>> regards,
>> bogdan
>>
>> Konstantinos Koutsopoulos wrote:
>>     
>>> Hi Bogdan,
>>>
>>> thanks for the response, but I actually need the ports to remain the 
>>> same.
>>> The address modification is convenient.
>>>
>>> Kostas
>>>
>>>
>>> Bogdan-Andrei Iancu wrote:
>>>  
>>>       
>>>> Hi Kostas,
>>>>
>>>> If you want to change only the port, try the mangle module:
>>>>    http://www.openser.org/docs/modules/1.2.x/mangler.html#AEN99
>>>>
>>>> Regards,
>>>> Bogdan
>>>>
>>>> Konstantinos Koutsopoulos wrote:
>>>>    
>>>>         
>>>>> Hi,
>>>>>
>>>>> I am deploying openser 1.2.2-notls on a machine with public IP.
>>>>> On the same machine I run a sip client (A) that registers with the
>>>>> above openser.
>>>>>
>>>>> On an another machine behind NAT (typical adsl router) I use a sip 
>>>>> client (B)
>>>>> to register with the above openser and try to invite sip client A.
>>>>>
>>>>> I do not use any NAT-traversal techniques (the outgoing packets from
>>>>> B are modified by NAT and reach openser, responses are received by
>>>>> B through NAT due to statefull (?) routing on the NAT).
>>>>>
>>>>> The SIP messages reach their destination properly and moreover
>>>>> the IP addresses in the SDP (from B) are updated by openser
>>>>> to indicate the external interface of NAT. This is very useful in
>>>>> my case since the client A sends the media packets to the proper
>>>>> address (I also configure virtual servers on the adsl router to have
>>>>> these forwarded to B). However, the port numbers in the SDP are
>>>>> also updated (usually by an offset of +16) which hinders the media 
>>>>> session
>>>>> from A to B since B is expecting the packets on other ports.
>>>>>
>>>>> Is there any way to have the ports remain unaltered during the 
>>>>> above operation?
>>>>>
>>>>> Thanks in advance,
>>>>>
>>>>> Kostas
>>>>>