Chapter 9: Planning for and Installing ISDN

ISDN Primary Service

NYNEX's implementation of the standard PRI is called ISDN Primary Service, and is most often provided through a standard T1 (1.544Mbps) dedicated point-to-point line. The service enhances the capabilities of the basic T1 digital trunk by giving the user hour-by-hour or even minute-by-minute control over each individual 64Kbps channel.

For example, instead of having separate trunks for voice access, for incoming 800-number lines, for outgoing WATS services and the like, it is now possible to allocate almost any channel to any function, wherever and whenever it's needed. This variable allocation of trunks can either be programmed into a NYNEX central office switch, or can be offered through a growing range of bandwidth-on-demand controllers, multiplexers, codecs and other equipment at the customer's location.

The result, of course, is that more voice and data traffic can be handled through existing facilities, with a much more productive use of each trunk.

While one 64Kbps channel must be reserved for D-channel signaling, those installations with multiple PRIs may choose to have one D channel serve two, three or even four PRI trunks. Large customers can also consolidate their traffic to one or more interexchange carriers through a PRI connection to the central office, thereby eliminating separate connections to each IEC.

NYNEX's ISDN Primary Service is available today from many central offices throughout NYNEX. Its flexibility, power and call-by-call service capabilities can also be added to existing T1 trunks served by an appropriate digital switch.

Other Sections Of This Chapter:

Beginning Of Chapter 9
The Movement Towards Unity
NYNEX ISDN Services
ISDN Basic Service
ISDN Intellipath
ISDN Primary Service
ISDN Equipment
Wiring For ISDN
Getting Started Now