[Kamailio-Users] [OT] SIP ALG Detector released

Iñaki Baz Castillo ibc at aliax.net
Fri Jun 19 15:35:59 CEST 2009


2009/6/18 Daniel-Constantin Mierla <miconda at gmail.com>:

> thanks for it, sounds very useful. What I see missing here is the case when
> the alg screws the routing so the reply does not get back to phone (e.g.,
> via replaced on the way out but not changed back for reply), so it might be
> good to have like an ack when the reply was received by the UA.

However, the test is done in the client, not in the server. This is,
the ACK could tell the server that the reply was received, but if not,
what to do?


> Or maybe would be better to do the other way. The client sends the request
> encoded to the server, the server unecodes it, does the diff and decides
> whether it is a possible alg in the middle.

I was thinking about it, but it doesn't convince me since ALG's
usually "require" a "common" INVITE request with common SDP body. If
the INVITE sent by the client contains itself encoded, it wouldn't
look a "common" request and the ALG could react in any exotic way :(


> I think it is very useful, as the server would also know alg presence state
> :-).

That's would be a different approach. I decided to do the test just in
the client, so an user testing it doesn't require access to the
server. Also the server doesn't require to store results in DB and so.


Regards.



-- 
Iñaki Baz Castillo
<ibc at aliax.net>



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