Setting The National Bit - Cisco 10000 Series Configuration Manual

Interface Configuration Commands

Setting the National Bit

Use the national bit command to set bit 12 in the E3 frame, using the following format:
[no] national bit [0 | 1]
The default is 0.
Use the no form of this command to return to the default bit.
In the following example, the national bit is set to 1 on an E3 interface:
Router(config)# interface serial 1/0/0
Router(config-if)# national bit 1
Enabling Scrambling
Scrambling can prevent some bit patterns from being mistakenly interpreted as alarms by switches
placed between the DSUs. Use the scramble command to assist clock recovery on the receiving end
using the following format:
[no] scramble
The default is no scramble.
In the following example, scrambling is enabled:
Router(config)# interface serial 1/0/0
Router(config-if)# scramble
Cisco 10000 Series Router Line Card Configuaration Guide
15-16
Chapter 15 8-Port Unchannelized E3/T3 Line Card Configuration
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