[Asterisk-Dev] Routing NOTIFY Messages?

[Olle E. Johansson]

John J. Sawa wrote:

> Is it possible to route SIP NOTIFY messages through * ?
> 
> Basically, I have an external VoiceMail application that needs the 
> ability to send SIP NOTIFY messages to * users, in order to do MWI to 
> the SIP phones. I realize the asterisk voicemail application does this, 
> but does * have the ability to accept these SIP messages from another 
> application. If so, will my application have to REGISTER then INVITE the 
> phone then send the NOTIFY message?
> 
> Currently, my application can send NOTIFY messages directly to the 
> phones in order to turn on and off MWI, but I would really like to be 
> able to send these messages to * and have it handle the routing to the 
> endpoints as * knows all the endpoints due to registration and proxy 
> capabilities. Any input on if and how this can be done would be 
> appreciated.
Incoming NOTIFYs are not handled by Asterisk at all. Asterisk
sends outbound NOTIFY messages for MWI to SIP peers with
mailbox= definition in [peer] section of sip.conf.

The problem with routing incoming NOTIFY is how to handle them, as with
many other SIP non-call things in Asterisk,  Is the user part of
the URI an extension or a SIP peer? It's not obvious.
We can't easily have two name spaces, so today the default handling is
sending a NOTIFY to an extension. SUBSCRIBEs have more or less
the same problem, the implementation today allows SUBSCRIBE to
an Asterisk extension. Many Asterisk admins want to subscribe to
a SIP peer, which breaks the architecture somewhat.

The best solution today is to use a SIP proxy for doing this kind
of stuff.

/Olle