[OpenSIPS-Users] NOTIFY nat_keepalive - Bad Event

[Iñaki Baz Castillo]

2009/3/2 Dan Pascu <dan at ag-projects.com>:
>> Indeed, the OPTIONS may generate more traffic (depends on the
>> implementation - kphone sends with SDP also, other not). But when comes
>> to interoperability, OPTIONS is more accepted by end devices, rather
>> then NOTIFY (where the phone must implement the method and the event).
>
> I don't think the phone needs to implement or for that matter even be
> aware of the NOTIFY method. Any device should reply with a "not
> implemented" or "method not understood" negative reply to any method it
> doesn't support. Any reply will do for the purpose of keepalive, be it
> positive or negative. In practice I have not encountered any device that
> would not reply to a keep-alive NOTIFY.

Indeed. In fact a custom request could be used for pinging:

  COOL-PING! sip:qweqwe at qweqweqwe.com SIP/2.0

Any UAS receiving that request MUST reply "Not implemented".


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