ABSTRACT
Another form of packetized telecom is the Asynchronous Transfer Mode (ATM) which divides messages into equal sized packets called “cells.” ATM’s use was once confined to the carrier backone, but because of its built-in Quality of Service (QoS), it is being used increasingly as a toll-quality “last mile” connection from a home or business to an optical IP backbone infrastructure. (See Asynchronous Transfer Mode.)
In most cases, organizations will want the cost savings of packet networks while conserving the known functionality and existing invest ments in their legacy PBXs. To do this, gateway routers need to support common channel signaling methods such as ISDN Primary Rate signal ing and Q.SIG, a PBX-to-PBX peer to peer signaling standard that allows
interoperability between value-added PBX functions such as conference calling and call-forwarding.
