Configuring Sonet Overhead - Cisco 10000 Series Configuration Manual

Other Configuration Commands

Configuring SONET Overhead

You can use the pos flag command to assign values for specific elements of the frame header. This
command is typically used to meet a standards requirement or to ensure interoperability with another
vendor's equipment.
pos flag [c2 value] [j0 value] [s1s0 value]
[no] pos flag [c2 value] [j0 value] [s1s0 value]
Where:
•
•
•
The default values are c2—0xCF, j0—0x01, and s1s0—0.
Use the no form of the command to restore the default values.
In the following example, the c2 bit is set to 0xCF:
Router(config)# interface pos 5/0/0
Router(config-if)# pos flag c2 0xCF
Configuring Packet over SONET SPE Scrambling
You can set the 1-Port OC-48/STM-16 Packet over SONET line card to scramble the Packet over SONET
synchronous payload envelope (SPE) using the pos scramble-atm command. 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
You can enable loopback testing of data transmitted from the PRE to the OC-48 line card and back, by
using the loopback command in interface configuration mode.
loopback [line | internal]
[no] loopback [line | internal]
Where:
internal loops packets received from the route processor back into the line card to the route processor
without being sent to the line.
Cisco 10000 Series Router Line Card Configuaration Guide
14-8
c2 is a path signal identifier, and value is one of the following:
0xCF for PPP or HDLC without scrambling
–
0x16 for PPP or HDLC with scrambling
–
j0 is the section trace byte, and value is 0x1 for interoperability with SDH devices.
s1s0 is part of the payload pointer byte, value is 0 for OC-48c and 2 for AU-4.
Chapter 14 1-Port OC-48/STM-16 Packet over SONET Line Card Configuration
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