Cisco 10000 Series Configuration Manual page 272

Other Configuration Commands
The following example directs the router to switch to internal clocking when it receives an S1 SONET
overhead byte with a value of 0xF:
pos flag s1-byte rx-communicate
The default for the pos flag s1-byte rx-communicate command is disabled or off.
Configuring Packet over SONET SPE Scrambling
The pos scramble-atm command allows you to scramble the Packet over SONET synchronous payload
envelope (SPE). SONET payload scrambling applies a self-synchronous scrambler to the SPE of the
interface to ensure sufficient bit transition density.
pos scramble-atm
[no] pos scramble-atm
The default is no Packet over SONET SPE scrambling.
Use the no form of the command to disable scrambling.
In the following example, scrambling is enabled:
Router(config)# interface pos 5/0/0
Router(config-if)# pos scramble-atm
Configuring Loopback Testing
To enable loopback testing of data transmitted from the PRE line card to the 1-Port OC-12 Packet over
SONET line card and back, use the loopback command in interface configuration mode.
loopback [line | internal]
[no] loopback [line | internal]
Where:
Both line and internal do the following:
•
•
Use the no form of the command to stop the loopback test.
For more information on loopbacks, refer to the online
Troubleshooting
In the following example, a loopback is set for the 1-Port OC-12 Packet over SONET line card in slot 5:
Router(config)# interface pos 5/0/0
Router(config-if)# loopback line
Cisco 10000 Series Router Line Card Configuaration Guide
13-6
Loop any data received at the 1-Port OC-12 Packet over SONET line card network interface back
into the network
Loop any data received at the 1-Port OC-12 Packet over SONET line card network interface back
into the PRE card
Guide.
Chapter 13 1-Port OC-12 Packet over SONET Line Card Configuration
Cisco 10000 Series Internet Router
OL-8834-04