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PA-POS-2OC3 Two-Port Packet-over-SONET Port Adapter Installation and Configuration
OL-3028-06
Chapter 4 Configuring the PA-POS-2OC3
Making a Back-to-Back Connection
Making a Back-to-Back Connection
This section provides an example of two sample configuration files from a Cisco 7200 VXR router and
a Cisco 7401ASR router connected back-to-back through their OC-3 interfaces.
Step 1
To connect two PA-POS-2OC3-equipped routers back to back, attach the appropriate cable between the
OC-3 interface port on each PA-POS-2OC3.
By default, the PA-POS-2OC3 uses loop timing mode.
Step 2
To specify that the Cisco PA-POS-2OC3 port adapter generates the transmit clock internally, add the
clock source internal
command to your configuration (see the first router example above:
clock source
internal
).
Note
For back-to-back operation, at least one of the connected OC-3 interfaces
must
be configured to supply
its internal clock to the line.
First Router
interface POS 3/0 <to select port 0 of PA-POS-2OC3 in a Cisco 7200 / Cisco 7401 series
router>
interface POS 3/1 <to select port 1 of PA-POS-2OC3 in a Cisco 7200 / Cisco 7401 series
router>
ip address 10.0.0.10 255.255.255.0
no keepalive
clock source internal
Second Router
interface POS 3/0 <to select port 0 of PA-POS-2OC3 in a Cisco 7200 / Cisco 7401 series
router>
interface POS 3/1 <to select port 1 of PA-POS-2OC3 in a Cisco 7200 / Cisco 7401 series
router>
ip address 10.0.0.20 255.255.255.0
no keepalive
