Issue 4 October 2002 135555-233-116
9
DS1/T1 CPE loopback jack
This chapter provides information on how to install and use a DS1 loopback jack
to test the DS1 span between the Avaya Media Server or Gateway an d the
network interface point. The loopback jack is required when DC po wer is at the
interface to the integrated channel service unit (ICSU).
NOTE:
Do not remove the loopback jack after installation. It should always be
available for remote tests of the DS1 span.
NOTE:
For G700 Media Gateway systems, the channel ser vice unit (CSU) is
integrated within the MM710 board. This means that t here is no need for a
separate external device. For earlier media gateway sy stems, the integrated
channel service unit (ICSU) — also known as the 120A2 — is a separate
device that plugs into the back of the media gateway.
For G700 Media Gateway systems, the loopback jac k isolates the MM710
internal CSU from the DC power and properly loops the DC span power.

Installing a loopback jack

You can install a loopback jack with or without a smart jack.

With a smart jack

Install the loopback jack at the interface to the sma rt jack, if possible. This position
provides maximum coverage of CPE wiring when rem ote loopback tests are run.