Alexander,
Btw, did you look at Kamailio which merged OpenIMS
developments some time ago?
No I hadn't. Now that I have, I wished I didn't. IMS sure looks like a
good barrier to entry. There's more to it than the proxy though (call
continuity / handover requires B2BUA from what I just read, which makes
sense).
[SMS]
An issue with e-mail, as I see it, is that it relies
on "polling"
model, while SMS is "push" model in its heart.
Good point; again, my limited knowledge of GSM tech in play.
Jabber is an interesting idea! The only issue I see is
that it
requires a TCP connection for every mobile connected to a BTS [...]
Not if you use a Jabber chatroom, but in that case you're better off using
AMQP anyhow since it really is a machine-to-machine alternative.
My understanding of AMQP is that you can subscribe to multiple queues
over a single connection so that should scale OK. (Based on my limited
experience with node-amqp.)
S.