Switching to VoIP

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Customer Premises Equipment

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Switches

When you hear somebody refer to a switch that resides on the customer premises,

that usually means a PBX or a KSU. See Chapter 1 for a refresher on PBXs and KSUs

if needed.

The Demarc

The Demarc, or demarcation point, is the point at which telephone company–owned

facilities terminate. Usually a cross-connection point or wiring terminal near the

exterior of a building or outside it, the demarc is where the phone company’s wiring

connects to privately owned facilities. Typically, the demarc is where the phone com-

pany’s troubleshooting stops, as well.

“Inside Wiring” and the Cable Plant

Inside wiring is the privately owned network of communications cabling and wiring

terminals located on the customer side of the demarc. Inside wiring could be simple,

two-pair wiring that connects a bunch of four-pin phone jacks (as in a house), or it

could be a centralized distribution of cabling throughout the building—also called

the cable plant.

Any telephone equipment or data networking equipment that exists

on the customer’s side of the demarc and is maintained by the tele-

phone company is called customer premises equipment (CPE).

CP Distribution Frames

Customer premises distribution frames are cross-connect blocks, terminals, or patch

panels where endpoint locations ...