[Serdev] Can SER determine NAT type?

[Nils Ohlmeier]

On Friday 23 September 2005 20:54, Federico Giannici wrote:
> Nils Ohlmeier wrote:
> > On Friday 23 September 2005 20:35, Federico Giannici wrote:
> >>Nils Ohlmeier wrote:
> >>>RFC 4028
> >>
> >>Really interesting!
> >>
> >>Now the question is obvious: has anybody developed a timers module???
> >
> > There is no real need for a timers module, as the UAs and gateways need
> > to support the session timer first.
> > Only in the scenario where only one side of the call support the session
> > timer the proxy can add the required headers to force this one side to
> > use the session timer anyway.
>
> Hummm....
> I made only a first, very rapid, reading of the RFC, but as I understood
> it, one proxy or the UAS have to EXPLICITELY activate the timers.
> Doesn't it?

I think the usual case is that both sides support it. In this case it gets 
activated more or less automatically. I'm not 100% sure but I think in this 
case the proxy is allowed to change (reduce) the SE-Expires values.

The second scenario is that either the UAC or UAS only supports it. In this 
case the proxy can jump in and requests the session timer. For this scenario 
a new module might be helpfull as the operations in IMHO are not that obvious 
to achieve with the textops. But that strongly depends on your point of view.

  Nils