
1-4 CHAPTER 1: GETTING STARTED
Benefits of ISDN
ISDN is an extension of the national and international public switched telephone network, which offers a digital
■Fast call setup times, typically taking less than one second for national calls.
■Greater bandwidth with multiple channels.
The basic rate service, often referred to as ISDN 2, carries two 64 Kbps (or possibly two 56 Kpbs in USA) user channels, called B channels and one 16 Kbps control channel called the D channel. The line service is presented into the customers premises through a standard RJ45 socket.
A significant aspect of the ISDN service is that it can be provided over the same wiring that was installed for the original telephone service. Therefore, ISDN can be made available relatively cheaply almost anywhere that previously had access to the analog system.
The cost of installation and rental of basic rate ISDN lines has dropped to the point where it is extremely attractive as regards cost and performance.