Cisco ASR 1000 Configuration Guide

13-8
Cisco ASR 1000 Series Aggregation Services Routers SIP and SPA Software Configuration Guide
OL-14127-08
Chapter 13 Configuring the POS SPAs
Configuration Tasks
Modifying SONET Payload Scrambling
SONET payload scrambling applies a self-synchronous scrambler (x43+1) to the Synchronous Payload
Envelope (SPE) of the interface to ensure sufficient bit transition density.
The default configuration is SONET payload scrambling disabled.
SONET payload scrambling must be configured to be the same on both ends of the POS link.
To modify SONET payload scrambling, use the following command in interface configuration mode:
To disable SONET payload scrambling, use the no form of this command.
Verifying SONET Payload Scrambling
To verify SONET payload scrambling, use the show interfaces pos privileged EXEC command and
observe the value shown in the “Scramble” field.
The following example shows that SONET payload scrambling is disabled for interface port 0 on the
POS SPA installed in subslot
0 of the SIP that is located in slot 2 of the Cisco ASR 1000 Series Routers:
Router# show interfaces pos 2/0/0
Hardware is Packet over Sonet
Internet address is 10.0.0.1/24
MTU 9216 bytes, BW 622000 Kbit, DLY 100 usec, 
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, crc 16, loopback not set
Keepalive not set
Scramble disabled
Configuring the Encapsulation Type
By default, the POS interfaces support High-Level Data Link Control (HDLC) encapsulation. The
encapsulation method can be specified as HDLC, Point-to-Point Protocol (PPP), or Frame Relay. The
encapsulation type must be configured to be the same on both ends of the POS link.
To modify the encapsulation method, use the following command in interface configuration mode:
Verifying the Encapsulation Type
To verify the encapsulation type, use the show interfaces pos privileged EXEC command and observe
the value shown in the “Encapsulation” field.
Command Purpose
Router(config-if)# pos scramble-atm Enables SONET payload scrambling.
Command Purpose
Router(config-if)# encapsulation 
encapsulation-type
Specifies the encapsulation method used by the
interface, where:
• encapsulation-type—Can be HDLC, PPP, or
Frame
Relay. The default is HDLC.

Cisco ASR 1000 Specifications

General

Brand	Cisco
Model	ASR 1000
Category	Network Router
Language	English