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

[Iñaki Baz Castillo]

El Jueves, 18 de Junio de 2009, Daniel-Constantin Mierla escribió:
> Hello Inaki,
>
> On 06/14/2009 02:17 AM, Iñaki Baz Castillo wrote:
> > Hi, as part of my personal battle against SIP ALG routers, I've created
> > an utility to detect such routers:
> >
> >   http://dev.sipdoc.net/wiki/sip-stuff/SIP-ALG-Detector
> >
> > It has two parts: client and server:
> >
> > Basically, the client node running into the LAN sends an INVITE to the
> > server node (running in a host with public IP).
> > The request could be modified by the LAN router if SIP ALG is enabled.
> > The server encodes the received request in Base64 and appends it to the
> > SIP response.
> > The client receives the response, decodes the body and gets the request
> > as it arrived to the server.
> > Then it creates a diff between the original request and the the request
> > the server node received. These differences are displayed in the screen.
> >
> > Both, UDP and TCP, tests are performed.
> >
> >
> > The client node is coded in Ruby and should work in any operating system
> > (if Ruby is installed).
> >
> > The server node is also coded in Ruby.
> >
> >
> > For those interested in try it, I have a server node running in my
> > personal server:
> >   87.98.230.161:5060
> > You can test the client against my server.
>
> 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.
>
> 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 think it is very useful, as the server would also know alg presence
> state :-).

Thanks Daniel, I'll think about it in order to improve it.


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