Configuring 32-Bit Cyclic Redundancy Check (Crc); Configuring 4-Bit Cyclic Redundancy Check - Cisco 7000 Series Hardware Installation And Maintenance Manual

interface, specify the slot and port address of the interface followed by the command nrzi-encoding.
In the example that follows, the first serial port on an FSIP in interface processor slot 2 is configured
for NRZI encoding:
7010# configure terminal
interface serial 2/0
nrzi-encoding
^z
To disable NRZI encoding on a port, specify the slot and port address and use the no nrzi-encoding
command.
For a brief overview of NRZ and NRZI, refer to "NRZ and NRZI Formats" in the chapter "Preparing
for Installation." For complete command descriptions and instructions, refer to the related software
documentation.

Configuring 32-Bit Cyclic Redundancy Check (CRC)

All interfaces (including the HIP) use a 16-bit cyclic redundancy check (CRC) by default but also
support a 32-bit CRC.
Note
resulting display indicates Part Number 81-0050-01, Hardware Version 1.0, you cannot use the
CRC-32 feature. If the display indicates Part Number 81-0050-02, Hardware Version 1.1, you can
use the CRC-32 feature.
CRC is an error-checking technique that uses a calculated numeric value to detect errors in
transmitted data. Because 32-bit CRC transmits longer data streams at faster rates, it provides better
ongoing error detection with less retransmits. However, both the sender and the receiver must use
the same setting.
The default for all serial interfaces is for 16-bit CRC. To enable 32-bit CRC on an interface, specify
the slot and port address of the interface followed by the command crc32. In the example that
follows, the first serial port on an FSIP in interface processor slot 2 is configured for 32-bit CRC:
7010# configure terminal
interface serial 2/0
crc32
^z
To disable 32-bit mode and return to the default 16-bit setting on a specific interface, specify the slot
and port address of the interface and use the no crc32 command.
For a brief overview of CRCs, refer to the section "Cyclic Redundancy Checks (CRCs)" in the
chapter "Preparing for Installation." For complete command descriptions and instructions, refer to
the related software documentation.

Configuring 4-Bit Cyclic Redundancy Check

The E1-G.703/G.704 interface supports 4-bit CRC in framed mode only. CRC-4 is not enabled by
default.
To enable CRC-4 on the E1-G.703/G.704 interface, specify the slot and port address of the interface
followed by the command crc4. In the example that follows, the top port on an FSIP in interface
processor slot 3 is configured for CRC:
To determine if your HIP will support a 32-bit CRC, use the show diag command. If the
Installing and Configuring Processor Modules
Maintenance 5-49