LSSGR: Synchronization, Section 18
Document Number GR-518
Issue Number 01
Issue Date Jul 1994
Replaces TR-TSY-000518 Issue02
ABSTRACT: This Generic Requirements (GR) document updates the synchronization requirements for digital switching systems. This document now
serves as a pointer to GR-1244, Clocks for the Synchronized Network: Common Generic Criteria, where synchronization
requirements for DS1 (1.544 Mbps) equipment have been consolidated.
This document discusses:
- Timing Modes
- Internal Clock Requirements
- Synchronization Performance Monitoring Criteria
- DS1 Traffic Interfaces
- DS0 Traffic Interconnections
- Sync Status Messages
Digital switches are integrated into the current synchronization network as described in GR-436, Digital Network Synchronization
Plan. Synchronization performance is measured at the output Digital Signal level 1 (DS1) signal. Synchronization requirements for
Synchronous Optical Network (SONET) interfaces to digital switches are in GR-782, SONET Digital Switch Trunk Interface
Criteria. The requirements in this document apply to all digital switches, including all remote switches.
All Service Providers have adopted the Building Integrated Timing Supply (BITS) concept for intraoffice synchronization distribution
as described in GR-436. This concept requires all synchronized Network Elements (NEs) within an office to be timed externally by a
single master clock called the BITS clock. To be integrated into the BITS concept, all synchronized NEs must support the external
GR-518 replaced TR-TSY-000518.
Components of this product are:
Table of Contents:
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