Ordering ISDN Lines C-1
This appendix provides you with information you need before you order a basic rate ISDN line.
Ordering an ISDN Line
Before ordering an ISDN line, there are several things you should know about the different kinds
of services and the many options that are available. The various kinds of services are described in
this appendix. If services that your telephone company offer are not described, you should obtain
information from them before ordering your ISDN line.
Connecting Devices to a Basic Rate ISDN
It is possible to have up to eight devices share a Basic Rate ISDN line with its two 64 KBps B (or
bearer) channels and one 16KBps D (or signaling) channel; however, only two devices can make
or receive calls over the B channels at any one time. These devices could include ISDN telephones,
Group 4 fax machines, Nautica Series bridges or routers, and terminal adapters that allow other
types of equipment, such as computers and analog telephones, to be connected to ISDN lines.
Depending on the types of the devices you want to attach to your line, you should discuss with
your telephone company whether you want the line to be capable of carrying voice traffic, data, or
both.
The simplest configuration, known as point-to-point operation, is when only one device is
connected to the line. When several devices share a line, the configuration is known as multipoint
operation. In multipoint configurations, it is necessary to be able to distinguish between devices,
and this is normally done by giving each device a distinct telephone number (also referred to as a
directory number).
NGRRT210.BK Page 1 Friday, October 17, 1997 2:37 PM