Cisco 3825 - Manual (Page 62)

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Cisco 3825 Mobile Wireless Edge Router Software Configuration Guide
OL-15667-03
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
Clock Source Command
The clock source command configures the source for synchronization of the interface transmit clock.
Configure clock source line if the router is deriving its clock externally from the connected device.
Configure clock source internal if the router provides the master clock (for example, either the internal
clock or the network clock).
The show network-clocks command allows verification of the clocking configuration.
mwr2#sh network-clocks
Network Clock Configuration
---------------------------
Priority Clock Source Clock State Clock Type
1 E1 0/0/0 GOOD E1
10 Backplane GOOD PLL
Current Primary Clock Source
---------------------------
Priority Clock Source Clock State Clock Type
1 E1 0/0/0 GOOD E1
The previous output of show network-clocks corresponds to the following configuration (see Figure 4-2
for description of how the clocking is done):
no network-clock-participate slot 1
network-clock-participate wic 0
network-clock-participate wic 1
network-clock-participate wic 2
no network-clock-participate aim 0
no network-clock-participate aim 1
network-clock-select 1 E1 0/0/0
controller E1 0/0/0
clock source line
channel-group 0 timeslots 1-31 speed 64
Figure 4-2 Clocking Example
1. The BSC provides clock synchronization to the MWR_A router.
2. The MWR_A router receives clock from the BSC via port 0/1/0 and distributes to port 0/0/0.
3. The MWR_B router receives clock from the MWR_A router via port 0/0/0 and distributes to port
0/1/0.
4. The Base Transceiver STATION (BTS) receives clock synchronization from the MWR_B router.
5. The clock synchronization from the BSC is propagated through the network to the BTS.
Clocking ----------------------------------------------->
0/1/0 0/0/0 0/0/0 0/1/0
BSC---z___MWR_A---z___MWR_B---z____BTS
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