Cisco ASR 1000 Configuration Guide

16-15
Cisco ASR 1000 Series Aggregation Services Routers SIP and SPA Software Configuration Guide
OL-14127-08
Chapter 16 Configuring the 2-Port and 4-Port Channelized T3 SPAs
Configuration Tasks
0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs
713 Unavail Secs, 0 Stuffed Secs
357 Near-end path failures, 0 Far-end path failures, 0 SEF/AIS Secs
Configuring Scramble
T3 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).
To configure scrambling, use the following commands:
Verifying Scramble Configuration
Use the show interface serial command to display the scramble setting:
Router# show interface serial3/0/0
Serial3/0/0 is down, line protocol is down
Hardware is SPA-2XCT3/DS0
MTU 4470 bytes, BW 44210 Kbit, DLY 200 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, crc 16, loopback not set
Keepalive set (10 sec)
Last input never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts (0 IP multicast)
0 runts, 0 giants, 0 throttles
0 parity
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
0 packets output, 0 bytes, 0 underruns
0 output errors, 0 applique, 4 interface resets
0 output buffer failures, 0 output buffers swapped out
Command Purpose
Router# configure terminal Enters global configuration mode.
Router(config)# interface serial slot/subslot/port Selects the interface to configure and enters
interface configuration mode.
• slot/subslot/port—Specifies the location of the
interface. See also the
“Specifying the
Interface Address on a SPA” section on
page 16-7.
Router(config-if)# scramble [0 | 1] Enables scrambling. Scrambling is disabled by
default.
• 1—Enabled.
• 0—Disabled.

Cisco ASR 1000 Specifications

General

Brand	Cisco
Model	ASR 1000
Category	Network Router
Language	English