Touch-Tone calling may also be available as an extra-cost option on Centrex I systems. ... It can make or receive any type of call unless it carries some kind of restriction on outgoing calls, such as restriction from the ability to dial toll calls or anbsp;...
|Title||:||How to cut costs and improve service of your telephone, telex, TWX, and other telecommunications|
|Author||:||Frank K. Griesinger|
|Publisher||:||McGraw-Hill Companies - 1974|