Esa Maintenance Overview; Functional Description; Esa Hardware Representation - Nortel DMS-100 Series Maintenance Manual

4 ESA maintenance overview

Functional description

The Outside Plant Module (OPM) with the Emergency Stand-Alone (ESA)
feature package NTX154AA is a different configuration than the standard
OPM. Special hardware components are required in addition to the ESA
software. This chapter treats the ESA configuration separately.
When the OPM is a remote configuration, defective or severed communication
links between the OPM and the host site can interrupt service. The ESA
feature package allows the OPM to provide stand-alone call-processing ability
if the OPM loses communication with the host. With the ESA feature package,
the OPM imitates the call processing functions of the Line Trunk Controller
(LTC) and the central control (CC).

ESA hardware representation

Figure "ESA hardware configuration" illustrates the ESA hardware
configuration from the point of the MAP terminal. In the figure, the OPM is a
C-side node for the ESA processor and the Remote Maintenance Module
(RMM). In this occurrence, the OPM is not in the ESA mode.
In the following figures, links 0 and 1 to the RMM are DS30A links, a link can
support 30 channels. Links 2 and 3 to the ESA processor are single-channel
message links.
DMS-100 Family OPM Maintenance Manual ISN07 (TDM)/SN07 (DMS) and up
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