[asterisk-users] SIP CallerID Question

[Brent Davidson]

I have several branch offices all running Asterisk PBX's that register 
to each other via SIP so that calls can be transferred from office to 
office.  Everything is working great on the office to office transfers, 
but I'd like to somehow make the CallerID more useful.  Currently if an 
extension at Office1 dials an extension at Office2 the CID on the phone 
at Office2 says "Office1".  The same thing happens if a person at 
Office1 transfers an incoming call to Office2.  The caller ID at Office2 
always just says "Office1".

What I would like to happen would be when Bob at Extension 12 at Office1 
calls Office2 the caller ID at office 2 would say "Bob" in the name 
files and "12" in the number field.  If Bob does a blind transfer to an 
extension at Office2 I would like the caller ID on the Office2 phone to 
display the original caller's name and number.

I've read most of the documentation on the CallerID variables, but am 
still having a bit of trouble wrapping my head around the necessary 
logic to accomplish what I need to do, (mainly because I'm in the middle 
of a totally unrelated project and am having trouble multi-tasking).  
Could anyone give me a starting point?

Thanks,
Brent