[asterisk-users] Connecting peer if the peer is already connected

[Luca Bertoncello]

Dave Platt <dplatt at radagast.org> schrieb:

> Were you trying to register the PC using the *correct* credentials used
> by your phone (the right username and password), or *incorrect*
> credentials (wrong password)?

Of course, with the CORRECT credentials... :)

> If your PC offered up the correct credentials, then I believe it's
> entirely normal behavior for Asterisk to accept this registration, and
> "bump off" the previous registration which used these same credentials.

Right! This is what happens... And what I'd like to correct...

> Asterisk (and most SIP servers) will treat this situation as an "Oh,
> this is a valid user of mine who has moved to a different IP address."
> 
> The same thing would happen if your cellphone were (for example) to
> switch from cellular IP to WiFi, or vice versa, or (in many cases) moved
> from one service area to another.

Well, if I'm on WiFi I surely don't need my cellphone in Asterisk, since I
use it only to receive calls if I'm not at home (holiday)

> The way you avoid confusion between multiple devices, is use different
> (unique) credentials for each SIP client... and, of course, use strong,
> difficult-to-guess passwords.

All client have different credentials and the password are random (32 chars).

> If you were to somehow tell Asterisk "Don't accept a different
> registration for my cellphone user XXXX, if user XXXX is already
> registered", you could quite easily find yourself unable to register the
> cellphone with Asterisk for a prolonged period of time... the PC could
> lock you out, and the cellphone could lock *itself* out every time it
> moved from one IP network to another.

Well, as I said, this is not a problem for me...
How can I do that? And, how can I for example send an E-Mail if the client
connect?

Thanks
Luca Bertoncello
(lucabert at lucabert.de)