ABSTRACT: This Generic Requirements document (GR) presents the Telcordia and participating industry representatives' view of information related to synchronization of telecommunications service providers' digital networks. In general, it is expected to be of use to service provider personnel (e.g., synchronization coordinators), synchronization product suppliers, and manufacturers of equipment that interfaces with synchronization products.

This Issue 2 includes significantly more information related to the distribution of Time of Day (ToD) synchronization within networks and the distribution of synchronization over packet-based networks. It includes:

• Revision of text to consistently refer to the set of equipment that provides timing to multiple traffic-carrying Network Elements (NEs) in a particular site (e.g., a CO) as the BITS clock
• Deletion of information related to LORAN signals
• Revision of Section 7.3.1 to reflect the fact that Threshold Crossing Alerts (TCAs), not alarms, are generated as part of the Performance Monitoring (PM) process
• Modifications to distinguish between 64 kb/s logical channels (DS0s) and 64 kb/s physical layer signals (DS0A signals)
• Reorganization and modification of the information in Section 2 regarding the need for synchronization in telecommunications networks
• Reorganization of Sections 3 and 4 so that Section 3 focuses on the stratum hierarchy, and Section 4 discusses both intraoffice and interoffice timing distribution
• Addition of text related to a Timing Signal Generator's (TSG?s) possible support of frequency reference output signals other than the DS1 and CC signals that have traditionally been used in North American applications
• A complete revision of Appendix A to reflect the current holdover-related criteria applicable to the various levels of standardized clocks.