Call-ID SIP headerthrough AMI?

Hello!

We have a few PC running a software with an embedded SIP phone.
In server side we have a daemon connected to Asterisk through AMI to send commands.

PC software send AMI commands to daemon to do some actions, but we cannot identify in unambiguous way the calls. We were using CallerID(num) field, but there could be “anonymous” calls or several calls with same CallerID(num) (if the come from same ISDN).

Is there any field which identify unambigious a call, i.e., “call-id” SIP header, that is accessible either from SIP phone and from AMI?

I made this:

When NewChannelEvent or BridgeEvent, I send CLI command with CommandAction:
“core show channel CHANNEL”

I get “SIPCALLID=” from response among other fields.