[Asterisk-Users] unclear about IAX

[Lal, Deepak (Contractor)]

Hello everyone:
I have a few questions about IAX. As I understand IAX is used for Inter-*
communications.
1. How do the asterisk boxes communicate? Is it over IP or some other mechanism
(T1 trunk?)
2. If I have a scenario where I'd like to use * as a PBX in a Small to medium
enterprise and at the same time use another Asterisk box at a service providers
office where it connects to a PSTN and the internet. Would such a setup work
with IAX?
3. Is there some documentation about setting up IAX and different deployment
scenarios?

Thanks for your help.
Deepak