Cisco ASR 14000 Series Command Reference Manual page 256

crc (POS)
crc (POS)
To set the length of the cyclic redundancy check (CRC) on a Packet-over-SONET/SDH (POS) interface,
use the crc command in POS configuration mode. To return the CRC setting on a POS interface to the
32-bit default setting, use the no form of this command.
Syntax Description
16
32
Defaults The default CRC mode is 32 bits.
Command Modes POS configuration
Command History Release
Release 3.7.1
Usage Guidelines To use this command, you must be in a user group associated with a task group that includes the proper
task IDs.
CRC is an error-checking technique that uses a calculated numeric value to detect errors in transmitted
data. The designators 16 and 32 indicate the length (in bits) of the frame check sequence (FCS). A CRC
of 32 bits provides more powerful error detection, but adds overhead. Both the sender and receiver must
use the same setting.
CRC-16, the most widely used error checking method throughout the United States and Europe, is used
extensively with WANs. CRC-32 is specified by IEEE standard 802 and as an option by some
point-to-point transmission standards. It is often used on Switched Multimegabit Data Service (SMDS)
networks and LANs.
Task ID Task ID
pos-dpt
Examples In the following example, the 32-bit CRC on POS interface 0/1/0/2 is enabled:
RP/0/RP0/CPU0:router(config)# interface POS 0/1/0/2
RP/0/RP0/CPU0:router(config-if)# POS
RP/0/RP0/CPU0:router(config-if-pos)# crc 32
Cisco ASR 14000 Series Router Interface and Hardware Component Command Reference
HR-252
crc {16 | 32}
no crc {16 | 32}
Sets 16-bit CRC mode.
Sets 32-bit CRC mode. The default is 32 bits.
Modification
This command was introduced on the Cisco ASR 14000 Series Router.
Operations
read, write
Packet-over-SONET/SDH Interface Commands on Cisco IOS XR Software
OL-17228-01