[OpenSIPS-Users] Calling engage_media_proxy per branch

[Thomas Gelf]

Hi Richard,

thank you for your reply! I stopped using other routes to force
OpenSIPS into doing "forbidden" things a while ago. Mostly this
caused other issues - and usually there IS a reason why certain
methods are only allowed in certain route types ;-)

In this special case moving engage_media_proxy to a branch_route
could help to solve b) but would mess up a) if the NATless client
picks up the call. In my believes engage_media_proxy (as probably
designed to be dialog-based) would then modify SDP in the 200
OK packet, even if the corresponding INVITE hasn't been modified
(only the other branch has done so).

I must confess I didn't test it - that's at least what I suppose
it to do in it's current form.

Regards,
Thomas Gelf


Richard Revels schrieb:
> For scenario b I suspect you could just call a route from within the  
> failure route and engage the media proxy there.  I know you will be  
> able to make the function call without error, just never tested it to  
> see if it has any undesired side effects.  Like not actually working.
> 
> Richard Revels
> 
> On May 28, 2009, at 11:27 AM, Thomas Gelf wrote:
> 
>> Hi list,
>>
>> I really like engage_media_proxy() as it really makes life easier.
>> However, currently it is dialog-based and cannot be called in a
>> branch_route. This has some side-effect:
>>
>> a) if a call is forked to two users, one behind NAT and one with
>>   non-symmetric router and STUN or on public IP, mediaproxy is
>>   always used, even if the client without NAT picks up the call.
>>
>> While I could live with this, a second scenario is really ugly:
>>
>> b) A is calling B, both with public IP. B issues a conditional
>>   call forward (30x) to C, with C being behind NAT. As far as
>>   I understood the module there is no way to "engage" Mediaproxy
>>   in this scenario.
>>
>> What I would like to know is:
>>
>> - is there a known workaround for this issue, that I can apply
>>  to my config script?
>> - is it planned to change engage_media_proxy to make it "branch-
>>  aware"?
>> - if you can acknowledge neither of the above: do I really need
>>  to tear down/re-use Mediaproxy session on each ReINVITE? What
>>  is the current best practice in this case?
>>
>> Many thanks for your answers!
>>
>> Best regards,
>> Thomas Gelf