Symmetricom TimeHub 5500 User Manual

097-55501-01 Revision M – January 2009 TimeHub 5500 User’s Guide 27
Chapter 1 Description
Functional Overview
If both Clock cards are removed or become inoperable, the Management card
provides an unfiltered version of an input to the output cards (passthrough) when
the input levels are sufficient. This feature is available on Master or Remote Master
shelves with Clock and IMC cards equipped with hardware version “B” or higher and
firmware version R4315C or higher. For more information on passthrough, see
Passthrough Mode, on page 35.
NTP and 5 MHz Outputs
Figure 1-5 is a block diagram of the TimeHub 5500 with a mix of DS1/CC Output
Connector modules, NTP Server cards, and 5 MHz Output Connector modules.
Figure 1-5. Block Diagram for DS1/CC, NTP, and 5 MHz Outputs
NTP Outputs
Each NTP Server card provides two network connections that provide accurate
NTP packets for use in TCP/IP packet networks. A Symmetricom TimeSource 3x00
typically provides the Time of Day (ToD) input on the NTP Connector module.
5 MHz Outputs
The 5 MHz Output Connector module provides four 5 MHz outputs for use in TDM
telecom network equipment.

Symmetricom TimeHub 5500 Specifications

General

Brand	Symmetricom
Model	TimeHub 5500
Category	Data Loggers
Language	English