[cisco-voip] AT&T refuses to port some numbers to our new VoIP system

[Peter Pauly]

I wondered if anyone has run into this problem before and how they
dealt with it:

We have been converting all of our locations to CallManager and are
down to the last location. As we do the migration, we invoke
number-portability and move lines away from AT&T to another carrier
that sends those numbers over our ISDN trunks. All has been going
smoothly until now.

AT&T is refusing to port some of our numbers. They happen to be UCD's
(AT&T idea of a hunt group). They say the numbers are "RESERVED"
whatever that means. Is AT&T legally required to port numbers
regardless of their use, or are there exceptions?