A simple question re outbound CID of T1's

[ghurty]

I know it is possible to have different DID's coming in over the same PRI to asterisk.

But how do you go about sending out different outbound caller ID's on the same PRI? Do you set in in the extension/trunk settings (like in SIP) or does it have to matched to a particular trunk of the PRI, and the caller ID is hard coded in?

I usually deal with SIP/IAX not T1's.

Thanks