[asterisk-users] PRI vs "Digital Trunk"

[Barry D. Hassler]

Hi, can someone enlighten me as to the difference between a PRI and a
"Digital Trunk" (other than cost)?

I do understand PRI (B-channel signaling, incoming/outgoing call setup,
D channel for voice/data, etc), but I'm not quite sure how that compares
with what my vendor is calling a "Digital Trunk" (specifically in
contrast to a PRI). The PRI is about twice the cost. 

If this is just a channelized T1 (24 64k voice/data "channels'), would
they each be assigned a specific phone number, or is there further
flexibility in sending/receiving calls, callerid (receive or send), etc?

Feeling ignorant here....

Thanks!