[asterisk-dev] STUN support in chan_sip revisited

[Klaus Darilion]

Am 09.08.2010 14:11, schrieb Simon Perreault:
>> Thus Asterisk would need
>> a feature to send REGISTERs with the required high Expires header, but
>> reregisters much earlier although the registration has not expired.
>
> Yes!
>
> And note that this is 100% compliant with RFC 3261. The only purpose of
> the Expires header returned by the registrar is to inform the client of
> the registration's life-time. The client is free to re-register (or not)
> at any moment.
>
> The right value for the Expires header to be sent to the registrar could
> be determined automatically from the Min-Expires header that the
> registrar sends us when it rejects the initial REGISTER with a 423
> (Interval Too Brief). Asterisk would send a new REGISTER request with
> this value but the actual re-registration interval would be the one
> configured statically in sip.conf. Would that work?

I think yes. But IMO it is not elegant - using STUN or CRLF is more 
elegant. Although not defined in RFC3261, CRLF as keep-alive for UDP is 
well supported.

regards
klaus