Does CallerID determine if a call is local?

[w1ve]

So,

I'm going to be travelling where I cannot purchase a VOIP DID.

I want to have cheap, unlimited cell service for a couple of weeks. The local provider,
for $7/month, will allow me unlimited calling to/from ONE local number to the cell phone.

So, I'm wondering how a "local number" is determined? For example, I could call a Callback number on my piaf. I could then have my piaf call me using a spoofed callerid (I actually have a DID in the same NPA, but no one sells them in the one I want to use.)

Thoughts?

 

[jades]

That's exactly it. When I go to canada and get a prepaid plan they give me one local number for unlimited calling. So I set up a callback system where that local canadian number calls me back from piaf. Just double check with the carrier and make sure that they don't care whether or not the number is coming from their network.