scramble
To enable scrambling (encryption) of the payload on a T3 or E3 controller or on the PA-T3 and PA-E3 port adapters, 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 arguments or keywords.
Command Default
Scrambling is disabled.
Command Modes
Interface configuration
Command History
Release |
Modification |
---|---|
11.1CA |
This command was introduced. |
12.2(11)YT |
This command was integrated into Cisco IOS Release 12.2(11)YT and implemented on the following platforms: Cisco 2650XM, Cisco 2651XM, Cisco 2691, Cisco 3660 series, Cisco 3725, and Cisco 3745 routers. |
12.2(15)T |
This command was integrated into Cisco IOS Release 12.2(15)T. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
12.2SX |
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware. |
Usage Guidelines
T3/E3 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 showcontrollersserial or the showinterfacesserial commands.
For T3 controllers, all the DSU modes support scrambling except Clear mode.
For E3 controllers, only Kentrox mode supports scrambling.
Examples
The following example enables scrambling on the PA-E3 port adapter in slot 1, port adapter slot 0, interface 0:
Router(config)# interface serial 1/0/0
Router(config-if)# scramble
The following example enables scrambling on the controller in slot 1, port 0:
Router(config)# interface serial 1/0
Router(config-if)# scramble