Mobile - Mobile (free)

[Aimster]

Let's say two people are both on Cingular, but one calls the other on a blocked number. Will it still be free since it is mobile-mobile?

I thought cell phone companies couldn't really trace cell phone numbers so how would they know that the person who blocked their number is with Cingular?

 

[FoBoT]

companies know which numbers are on thier own network, those calls don't have to go outside of their own cell network

 

[tvbi]

if they can't trace..how can they connect your call?