[asterisk-dev] Implementing Paging on the Linksys SPA9XX phones

[John Lange]

On Wed, 2006-05-17 at 17:22 -0500, Kevin P. Fleming wrote:
> John Lange wrote:
> 
> > Can you give examples of which phones? I don't know what you mean by the
> > SIP/SDP model and google on those terms didn't turn up anything
> > meaningful with regard to paging.
> 
> Snom, for certain, supports multicast RTP, but it has to be done using
> the normal SIP/SDP method of sending an INVITE to the phone and telling
> it what multicast stream it should listen to (and whether it should
> auto-answer, etc.).

This could be what the Linksys phones are doing as well but I don't know
enough about the protocol to say for certain. In any case Asterisk
doesn't support it and it would be nice if it did. 

> > We are very interested in solving this issue because paging seems to be
> > the most often asked for feature in Asterisk that doesn't really exist.
> 
> It's not. The most asked for feature is key-system functionality,
> followed closed by T.38 media gateway support.

If by key-system functionality you mean line indicator lights when
people are on the phone then I second that. It is also very often
requested.

T.38 media gateway support would be nice but there are so many other
ways to solve this issue I don't consider it a priority. I've never had
that request. People just use analog lines for faxing in larger offices
or use a digital fax gateway.

> Doing paging the way we
> do it now seems to work for many people.

It can work but its not very scalable. Can Asterisk scale to a 100 phone
conference call in fractions of a second? And on phones that don't
support the auto-answer sip header its a bit of disaster requiring more
expensive multi-line phones in situations that otherwise wouldn't need
them.

Never the less I believe the current implementation will work well for
the SPA9XX phones in the specific case where we most need it since there
is only about 30 handsets.
---

Anyhow thats a bit off topic. I'm still hoping to get this implemented
in Asterisk somehow and if anyone else is interested in doing some
analysis on whats required to make it happen please let me know.

-- 
John Lange