Chapter 9: Planning for and Installing ISDN

ISDN Equipment

A growing range of LAN servers, bridges, routers, bandwidth controllers and other equipment is rapidly becoming available. Many manufacturers and suppliers of this equipment are listed in the appendix of this guide, and most provide expert advice and assistance in planning for ISDN.

Some Basic User Needs

The equipment needs of the individual user are relatively simple. The typical user will require some of the following:

A Network Termination Device.
An NT1, as it's called, links a BRI connection to the telephone network. It offers both line-conversion and line-testing capabilities. Some manufacturers incorporate this device into other components. For example, many terminal adapters and desktop computer circuit boards come with a built-in NT1.

A Terminal Adapter.
The TA is a protocol converter that adapts PCs, workstations and other equipment to ISDN. Some terminal adapters, especially those that come as a circuit board, include telephone jacks for connecting analog telephones or faxes, while many ISDN telephones come with a built-in terminal adapter and appropriate jacks for connecting a PC.

A Power Supply.
Unlike analog telephone service, ISDN requires more electrical power than can be supplied through a standard phone line. Thus each line needs its own power supply. Today, many NT1s, TAs and PC circuit boards come with their own built-in power supply.

An ISDN Telephone.
Powerful digital telephones that most often include a terminal adapter, an LCD screen for D-channel messaging and "softkeys" for call-management and call-control features.

An Aggregation Device.
While some aggregation devices are still sold as stand-alone units, a growing number of terminal adapters now include the electronics to aggregate, or bond, two B channels into a single higher-speed connection. Some, especially PC boards, also include an Ethernet bridge.

Also required, of course, is the equipment - PCs, workstations, video or sound systems, credit-card readers and the like - and software to be used in a specific application.

"Prices for ISDN equipment are declining rapidly," said DEC's Nultemeier. "As the market grows, prices will continue to come down while capabilities keep going up."

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