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Cisco 3825 Mobile Wireless Edge Router Software Configuration Guide
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Chapter 4 Configuring the Cisco 3825 Mobile Wireless Edge Router in a RAN-O Solution with the Command-Line
Clocking Requirements for Cisco 3825 Router
Figure 4-1 Clocking Example
The Base Station Controller (BSC) is responsible for providing the clock source into the network to
which the connected devices must synchronize its transmit clocks.
The BSC provides the clock source to the Cisco 3825 router, which is distributed to the participating
serial/ATM ports.
Clock-Related Commands
The following sections describe the uses of the clock-related commands:
• Network-Clock-Participate Command
• Network-Clock-Select Command
• Clock Source Command

Network-Clock-Participate Command

The network-clock-participate command allows the ports on a specified network module or
voice/WAN interface card (VWIC) or high-speed WAN interface card to use the network clock for
timing. For example:
mwr2(config)#network-clock-participate ?
aim AIM Module
slot Network Module Slot
wic WIC Module
Use “
aim”
keyword to identify Advanced Integration Module
Use “
wic”
keyword to specify the voice/WAN interface card

Network-Clock-Select Command

The network-clock-select command names a source to provide timing for the network clock and to
specify the selection priority for this clock source.
To ensure that the router uses the correct interface as the primary (highest priority) clock source, this
command must be present to configure the clocking priority for the system. To establish the clocking
hierarchy (in case the primary source goes down), the same command needs to be repeated with a
different priority for each interface:
network-clock-select 1 e1 0/0/0
network-clock-select 2 e1 0/0/1
Clocking ----------------------------------------------->
BSC---z___MWR_A---z___MWR_B---z____BTS
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