Here's the scenario: Customer has SIP trunks with DIDs from many, many, many different area codes from across the US. They want to be able to tag an outbound call with the local number they own based on the area code they are dialing. For example, if they were to dial [9]1-717-xxx-xxxx, based on the 1st few digits they dial, it would route to a matching ARS pattern and tag with the appropriate outpulsed caller ID (NSI717xxxxxxx). The other question is if this can be accomplished with SIP trunks or do I need PRI/ISDN to manipulate CID with ARS? Hope this helps...