User guide

4-17
Configuration Guide for Cisco DSLAMs with NI-2
OL-2074-03
Chapter 4 Configuring Digital Subscriber Lines
Setting DSL Profile Parameters
Enabling and Disabling Payload Scrambling
This section describes how to enable and disable cell payload scrambling on a DMT subscriber port.
Payload scrambling is enabled by default.
To disable payload scrambling, complete the following steps:
To enable payload scrambling, complete the following steps:
The two ends of a connection must have the same payload scrambling value—that is, payload scrambling
must be enabled at both ends or disabled at both ends. Otherwise, the line does not train.
Enabling or disabling payload scrambling does not cause the port to retrain.
Setting CAP Upstream and Downstream Baud Rate Margins
This section describes how to configure upstream and downstream baud rate margins for ATU-C CAP,
and ATU-C flexi CAP interfaces.
Cisco IOS supports provisioning additional baud rates for interface line codes. The following
rules apply:
• Valid rate, Cisco IOS selects a rate less than or equal to the rate that you specified.
• Invalid rate, Cisco IOS modifies the rate to the closest available rate that is less than or equal to the
rate that you specified.
In addition to the existing upstream 136 kilobaud rate, Cisco IOS also supports an upstream 17 kilobaud
rate and an upstream 68 kilobaud rate. You can independently enable or disable the new baud rates.
The following list contains the valid upstream/downstream pairs within the available rates:
• An upstream rate of 17 kilobaud is valid only with a downstream rate of 136 kilobaud.
• An upstream rate of 68 kilobaud is valid only with a downstream rate of 136 kilobaud or a
downstream rate of 340 kilobaud.
• All other combinations are valid.
Command Task
Step 1
DSLAM# configure terminal
Go to global configuration mode.
Step 2
DSLAM(config)# dsl-profile profile-name
Specify the profile-name for which you want to
disable payload scrambling.
Step 3
DSLAM(cfg-dsl-profile)# no payload-scrambling
Disable payload scrambling.
Step 4
DSLAM(cfg-dsl-profile)# end
Exit from profile configuration mode.
Command Task
Step 1
DSLAM# configure terminal
Go to global configuration mode.
Step 2
DSLAM(config)# dsl-profile profile-name
Specify the profile-name for which you want to enable
payload scrambling.
Step 3
DSLAM(cfg-dsl-profile)# payload-scrambling
Enable payload scrambling.
Step 4
DSLAM(cfg-dsl-profile)# end
Exit from profile configuration mode.