[Asterisk-Dev] IAX2 indepth question..

[Rob Thomas]

For those that noticed it flash by on the -users list, Grandstream might
be supporting IAX in the new GXP2000 (info available from
http://aussievoip.com.au/wiki-GXP-2000 etc).  Now whilst this is a great
idea, how would you go about monitoring extensions?  If you have a look
at the pictures linked from that page, you'll see that the phone has 7
buttons that imply they could be used as BLF's (which they're not, at
the current software revision). 

With SIP you can SUBSCRIBE and receive NOTIFYs - how would you implement
that with IAX2?  I've had a quick browse of the quasi-RFC and nothing
jumps out at me.  

Potentially, should this be implemented with a Push-style MWI (discussed
here recently) rather than the polling procedure which seems to be the
only way to do it?

--Rob