Specifications

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Cisco MGX 8850 (PXM45) and MGX 8950 Software Configuration Guide
Release 3, Part Number 78-14788-01 Rev. C0, January 2004
Chapter 2 Configuring General Switch Features
Configuring Clock Sources
Note The PXM45 provides a revertive function that can apply when the primary clock source fails. A failure
is a loss of the primary clock source after the switch has locked on to that clock source. If the primary
clock source recovers and revertive mode is enabled, the switch automatically reverts to the primary
source
The following command example shows how to configure a primary E1 external clock source at the
upper connector of the PXM45-UI-S3. Note the command punctuation.
mgx8850a.7.PXM.a > cnfclksrc primary 7.35 -bits e1
The next example configures a primary network clock source and enables the revertive option.
mgx8850a.7.PXM.a > cnfclksrc primary 7.36 -bits e1 -revertive enable
The last example disables the revertive function for an E1 BITS clock.
mgx8850a.7.PXM.a > cnfclksrc primary 7.36 -bits e1 -revertive disable
Enabling NCDP on a Node
Use the following procedure to enable NCDP on you network.
Step 1 Enter the cnfncdp [options] command to enable NCDP on the node, set timer values, and specify the
number of nodes in the clocking domain.
M8850_LA.8.PXM.a > cnfncdp -distributionMode 1 -maxNetworkDiameter 30 -hello 300 -holdtime
300 -topoChangeTimer 300
Table 2-8 describes the options available for the cnfncdp command.
Table 2-8 cnfncdp Command Parameters
Parameter Description
-distributionMode The clock distribution mode is either NCDP or manual. If manual, use
the cnfclksrc and its related commands for synchronization.
Possible entries: 1 for NCDP or 2 for manual clocking
Default = manual (2)
-maxNetworkDiameter Maximum network diameter measured in hops. This is the maximum
length of the spanning tree, in the range from 3 through 200.
Default = manual (20)
-hello Hello time Interval, in milliseconds, between PDUs. The range is from
47 through 60000 milliseconds.
Default = 500 milliseconds