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Expansion processing module (epm) – ZyXEL Communications Multi-service Access Platform MSAP2000 User Manual

Page 126

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7. Product Specification

MSAP2000 Technical Manual V3.0

7-19

7.8. Expansion Processing Module (EPM)

Overview

The Expansion Processing Module (EPM) co-works with the Expansion
Link Module (ELM) to provide capacity expansion for a single node.
The EPM is installed within the extension shelf, whereas the ELM is
installed within the main shelf.

The EPM provides the extension shelf’s with a synchronized clock, and
also converts and transmits the control commands sent from the Main
Processing Module (MPM).

Features
And
Benefits

„ Panel LEDS indicate status, faults, alarms, and network connection
„ Timing recovery circuit, with ultra-low jitter
„ Simplified insertion and monitoring procedures for STM-1 Overhead

Byte

„ Protection Switch functions
„ Clock synchronization recovery, and excellent phase lock loop

technologies

„ Alarm and fault monitoring and reporting
„ Digital cross-connection for all STM-1 Timeslots
„ Use of non-volatile memory devices for storage of performance data

Function
Diagram

Application

When more than one shelf is needed, installation of EPM in the
expansion shelf is needed. A corresponding ELM must be installed in
the main shelf and link with EPM using a multi-mode fiber patch-cord.

ELM

MPM

Module

Local node communication

Module

EPM

Module

Local node communication