Callid Session Variable

[len@Arena]

Hi, I need to confirm the values kept in the session object. When a script is executed the session object contains three variables: ani, callid and dnis.

It seems ani is the phonenumber that originally called the script and dnis is the extension number the script is registered to. From the various debugging sessions conducted it seems that the callid is composed of :
From_<ani>_to_<dnis>_menu_<dnis>_#2/45

The numbers after the # keep changing after every call. Any ideas what info these numbers represent?

[VAD_Support]

The final part of the callid is a sequence number. The idea is that the callid is unique. You may use it to distinguish two calls from the same origin to the same destination.

[len@Arena]

So in the example above (#2/45) the 45 would be a sequence number? What about the 2?

[VAD_Support]

The first part is the quantity of simultaneous calls, not sure if calls in the IVR or the entire PBX...