[sr-dev] why new tcp connection?

[Iñaki Baz Castillo]

El Sábado, 7 de Noviembre de 2009, Olle E. Johansson escribió:

> > However, the fact is that during a TCP dialog there "should" exist
> > *two* TCP
> > connections (assuming binding port = 5060):
> >
> > a) UA:random_port - Proxy:5060
> > b) Proxy:random_port - UA:5060
> >
> > If UA initiates the dialog the connection a) is created.
> > If Proxy sends an in-dialog request the connection b) is created.
> >
> > Of course b) is not created when using "alias" or forcing the proxy
> > to reuse
> > the connection established by UA (server solution).
> 
> Imaging having TLS. The B connection would not work unless we had a
> valid certificate in the UA.
> 
> For TLS each TCP connection needs a property on when it's allowed to
> reuse.

Annoying. Let me a question:

If UA is not behind NAT (but supports and uses sip-outbound), how many TCP 
connections would exist when communicating with the proxy?


PS: I insinst. How is possible that IETF has designed a protocol in which, by 
default, two TCP connections are required in a direct communication between A 
and B?



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