[asterisk-users] SIP, IAX2 and ISDN ISUP data

[Phil Lello]

Hi all,

I'm looking at my options for getting access to ISDN ISUP fields from
DDI numbers, when connecting to a 3rd party Asterisk server. This is for
a custom voicemail solution, and at this stage I want to avoid renting a
PRI.

The information I need to capture is:
- Calling Number
- Called Number (e.g. the DDI handling the call)
- Redirecting Number (e.g. the device diverting to the voicemail DDI)
- Originally Called Number (e.g. So if Adam phones Bob, Bob is diverted
to Charlie, and Charlie is diverted to Voicemail, then Adam probably
doesn't want Charlie's Voicemail).

I believe this information should be in SIP Divert headers, can someone
confirm this?

Do I get the same information if I use an IAX2 connection to connect a
local Asterisk server to an external one?

Does IAX2 route GSM/ISDN SMS between servers, and if so, would the
remote/ISDN connected server need to explicitly support this, or do the
remote cards look local?

Any help greatly appreciated,

Phil