Cisco ME-3600X-24CX Series Switch Chassis Configuration Guide, Release 15.2(2)S
Configuring Clocking and Timing
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Configuring Clocking and Timing

Table Of Contents

Configuring Clocking and Timing

Network Clocking Overview

Synchronous Ethernet

Synchronous Ethernet ESMC

Configuring Clocking and Timing

Configuring Synchronous Ethernet

Configuring an External Clock Source

Configuring Synchronous Ethernet ESMC

Verifying Clock-Related Settings


Configuring Clocking and Timing


Clock synchronization is important for a variety of applications, including synchronization of radio cell towers. While legacy TDM protocols incorporate timing features, packet-switched networks such as Ethernet do not natively include these features. The Cisco ME 3600X 24CX Series Switch supports legacy TDM technologies while supporting a variety of technologies that distribute clocking information over packet-switched networks.

The following sections describe the clocking and timing features available on the Cisco ME 3600X 24CX Series Switch.

Network Clocking Overview

Configuring Clocking and Timing

Network Clocking Overview

Clocking is typically distributed from the core network outward to the BTS or Node B at the network edge. The Cisco ME 3600X 24CX Series Switch receives and transmits clocking information using any of the following ports:

T1/E1

GigabitEthernet

BITS/SYNC port

1PPS

10Mhz

The Cisco ME 3600X 24CX Series Switch supports the following clocking types:

Synchronous Ethernet

Synchronous Ethernet

Synchronous Ethernet is a timing technology that allows the Cisco ME 3600X 24CX Series Switch switch to transport frequency information over Ethernet. Because frequency is embedded in Ethernet packets, synchronous Ethernet must be supported by each network element in the synchronization path. Synchronous Ethernet is defined in the ITU-T G.781, G.8261, G.8262, and G.8264, Telcordia GR-253-CORE, and Telcordia GR-1244-CORE standards.

Synchronous Ethernet ESMC

The Cisco ME 3600X 24CX Series Switch supports Ethernet Synchronization Message Channel (ESMC) to provide clock synchronization on Synchronous Ethernet. For more information about Ethernet ESMC , see Chapter 5 "Configuring Clocking and Timing."

Configuring Clocking and Timing

The Cisco ME 3600X 24CX Series Switch switch supports the following network clocking types:

Synchronous Ethernet—Allows the network to transport frequency and time information over Ethernet. To configure synchronous Ethernet, see Configuring Synchronous Ethernet.

Verifying Clock Settings—To verify a clocking configuration, see Verifying Clock-Related Settings.

Configuring Synchronous Ethernet

The following sections describe how to configure synchronous Ethernet timing on the Cisco ME 3600X 24CX Series Switch switch.

Configuring an External Clock Source

To configure an external clock source using Synchronous Ethernet, use the network-clock switch manual external R0 | R1 {{E1 {crc4 | cas |fas}} {T1 {d4 | sf | esf}} } command.

Switch(config)# network-clock switch manual external r0 e1 crc4 
 
   

Configuring Synchronous Ethernet ESMC

For instructions on how to configure synchronous Ethernet Synchronization Message Channel (ESMC), see Configuring Synchronous Ethernet in Cisco ME 3800x and ME 3600x Switch Software Configuration Guide

Verifying Clock-Related Settings

Use the following commands to verify the clock settings:

show network-clocks synchronization—Displays information about the network clocks.

For more information about these commands, see the Cisco ME 3800X and ME 3600X Switch Command Reference, Release 15.2(2)S.