scramble
To enable payload scrambling (encryption) on a serial interface, use the
scramble
command in interface
configuration mode. To disable scrambling, use the
no
form of this command.
scramble
no scramble
Syntax Description
This command has no keywords or arguments.
Command Default
Scrambling is disabled.
Command Modes
Interface configuration
Command History
Modification
Release
This command was introduced.
Release 3.9.0
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes appropriate task
IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator
for assistance.
Scrambling is used to assist clock recovery on the receiving end. Scrambling is designed to randomize the
pattern of 1s and 0s carried in the physical layer frame. Randomizing the digital bits can prevent continuous,
nonvariable bit patterns
—
in other words, long strings of all 1s or all 0s. Several physical layer protocols rely
on transitions between 1s and 0s to maintain clocking.
Scrambling can prevent some bit patterns from being mistakenly interpreted as alarms by switches placed
between the Data Service Units (DSUs).
The local interface configuration must match the remote interface configuration. For example, if you enable
scrambling on the local port, you must also do the same on the remote port.
To verify that scrambling is configured on the interface, use the
show interfaces serial
command.
Task ID
Examples
In the following example, scrambling is enabled on serial interface 0/3/0/0/0:10:
RP/0/RSP0/CPU0:router(config)#
interface serial 0/3/0/0/0:10
RP/0/RSP0/CPU0:router(config-if)#
serial
RP/0/RSP0/CPU0:router(config-if-serial)#
scramble
Cisco ASR 9000 Series Aggregation Services Router Interface and Hardware Component Command Reference,
Release 5.3.x
807
Serial Interface Commands on the Cisco ASR 9000 Series Router
scramble