Setup guide
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Cisco 6400 Software Setup Guide
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Chapter2 Basic NSP Configuration
Network Clocking
Configuring Network Clock Revertive Behavior
Revertive behavior enables the network clock to automatically switch to the highest priority clock source
available. When a clock failure is detected, the next highest priority clock source is selected. If revertive
behavior is not configured, the clock source will not switch back even when the failed (but higher
priority) clock source is restored.
To enable network clock revertive behavior on the NSP, use the following command in global
configuration mode:
Example
In the following example, the network clock reverts to the highest priority clock source after a failure:
!
network-clock-select 1 atm 2/0/0
network-clock-select 2 atm 2/0/1
network-clock-select 3 atm 1/0/0
network-clock-select revertive
!
Configuring Building Integrated Timing Supply Network Clocking
BITS network clocking enables the Cisco 6400 to derive network timing from the central office (CO)
BITS as well as from a clock recovered from a specified NLC interface. The Cisco 6400 can also
distribute the BITS network timing with stratum level 3 accuracy to other network devices.
The BITS Network Clocking feature requires the NSP with stratum 3/BITS (NSP-S3B) module.
Figure2-2 shows the NSP-S3B module faceplate.
Figure2-2 NSP-S3B Module Faceplate
In addition to enabling the BITS Network Clocking feature, the NSP-S3B allows the Cisco 6400 to serve
as a stratum 3 network clock source for other network devices. When no external clock source is
available, the NSP-S3B provides stratum level 3 internal timing on the Cisco 6400. Otherwise, the
NSP-S3B is identical to the default NSP.
For information about installing the NSP-S3B, see the Cisco 6400 UAC Hardware Installation and
Maintenance Guide.To see if the NSP-S3B is installed in the Cisco 6400 chassis, use the
showhardware EXEC command. The output will contain an “NSP-NC” controller type (Ctrlr-Type)
for each NSP-S3B in the chassis.
Command Purpose
Switch(config)# network-clock-select revertive
Configures revertive behavior on the network
clock.