What information is relevant to choosing an IP telephony centralized call processing model?

A.
multiple PRIs to the PSTN

B.
a campus of six buildings connected via an ATM backbone

C.
three small regional sales offices located in the three Western time zones

D.
centralized order processing, shipping, and billing for all customer products

E.
connectivity to a single service provider that hosts the company web site and provides for Internet access

F.
a single six-story building with an IDF on each floor and an MDF in the computer room on the second floor