Telos NX12 A3 USA Isdn Ordering Guide, Dealing with the Phone Company, Details, Details

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A3 USA ISDN Ordering Guide

This section applies to users in Canada & USA and is intended to help you when it comes time to order your ISDN lines. We assume you are familiar with ISDN’s basic concepts. If you have not read the ISDN section in the manual, doing so now will help you better understand the information that follows.

If you know who to call and you are ready to provide complete information, the ISDN ordering process can be simple and straightforward. This guide takes you through the process step-by- step. Telos support is always available to assist.

On one ISDN BRI circuit, there are three simultaneous bi-directional channels: two 64kbps “bearer” or “B” channels for the transmission of user information and one 16kbps “data” or “D” channel for call set-up and status communication. That is why this is sometimes called 2B+D service. You can use the B channels, but only the phone companies and equipment manufactur- ers can usually use the D channel. ISDN comes into your facility on two wires, just like plain old telephone service (POTS).

From the perspective of telephone network routing, each channel appears to be a separate line with it’s own number and independent dial-out capabilities. Since each has to be dialed or answered separately, they appear to be “lines” to users also.

The Nx12’s internal ISDN interface is used to connect to digital ISDN telephone lines. It easily adapts to the various types of service offered by the range of Central Office (CO) switches installed by telephone companies in the USA and Canada.

Dealing with the Phone Company

As is often the case when broadcasters interface with phone people, the lines of communication can get a little tangled.

The first order of business is to find someone who knows what ISDN is. While your usual account agent will be the normal entry point, you may be talking to a number of phone people before you find one who understands your needs.

Some of the regional Bell companies offer a single point of contact number for switched digital services, while some Telcos use “resellers”. Note that in some cases the phone company will need to do a “loop qualification” (line loss test) before they can verify that ISDN will be available at your location.

Details, Details

Protocols

In a perfect world, all ISDN terminal equipment would work with all ISDN lines, without