ISDN2

ISDN lines are primarily purchased by businesses and are capable of supplying voice and basic data services. In order to use them for voice services a PBX needs to be connected to handle the calls and connect them up to phone handsets. Unlike a basic PSTN you can’t simply connect a phone to it. ISDN2 connections, as the name suggests are supplied as pairs of channels (eg 2, 4, 6), they are also capable of supporting DDI numbers, unlike just the one you get with a PSTN line.

Scott Magee

<p>Managing Director of Cirrus IT Services (UK) Limited</p>