fec

Function

The fec command configures a forward error correction (FEC) mode for an Ethernet interface.

The undo fec command restores the default FEC mode of an Ethernet interface.

By default, the standard FEC mode of the ethernet interface is enabled.

This command is supported only on the NetEngine 8000 F2A.

Format

fec { standard | enhanced-i-4 | enhanced-i-7 | none }

undo fec

Parameters

Parameter	Description	Value
standard	Indicates the standard G.709 FEC mode.	-
enhanced-i-4	Indicates the enhanced G.9751.1 I/4 mode. This mode is supported only on the 10G OTN subcard or board.	-
enhanced-i-7	Indicates the enhanced G.9751.1 I/7 mode. This mode is supported only on the 10G OTN subcard or board.	-
none	Cancels the FEC mode.	-

Views

100GE interface view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
interface-mgr	write

Usage Guidelines

Usage Scenario

When an interface works in OTN mode, you can run the fec command to configure the FEC mode of the interface. When the interface works in LAN mode, the fec command cannot be configured.

The preceding FEC modes have different internal error correction algorithms. Different vendors support different FEC modes. The same FEC mode must be configured on interconnected devices. Otherwise, FEC bit errors may occur. If FEC bit errors occur, check the remote device's FEC mode and run the fec command to change the local device's FEC mode to be the same as that of the remote device.

Configuration Impact

The FEC mode configuration causes the threshold configured using the otn prefec-tca command to be changed to the following:

If the FEC mode is configured as none or standard, the associated FEC bit error alarm threshold is 1E-6 with a detection interval of 3s, and the clear alarm threshold is 1E-7 with a detection interval of 30s.
If the FEC mode is configured as enhanced-i-4 or enhanced-i-7, the associated FEC bit error alarm threshold is 5E-5 with a detection interval of 3s, and the clear alarm threshold is 5E-6 with a detection interval of 30s.

Precautions

You must set the same FEC mode for two connected interfaces.
An FEC mode must be set for a 100GE OTU4 interface according to the G.709 protocol requirement. Otherwise, an error is reported, or packet loss occurs.
When you run the fec command, note that the enhanced, enhanced-i-4, and enhanced-i-7 modes cannot be configured for different interfaces on the same subcard.
If an FEC mode is configured on an interface with a 100 Gbit/s CFP2 DWDM optical module inserted, the FEC mode configuration takes a maximum of 190s to take effect. To check whether the configuration takes effect, run the display this interface command. (The model of the optical module is OSNB00C02, 118Gbps(425.78/427.95)-CFP2-SMF-192.1-196.05THz-1200km-commercial.)
After the fec lhaul-sd configuration is complete, set the signal-coding dqpsk tx value based on the optical module type. For details about the parameter value, see the optical module description in the product documentation. Hardware Description-Optical Module-100Gbps CFP2 Optical DWDM Module.
In VS mode, this command is supported only by the admin VS.

Example

# Configure 10GLAN 0/1/0 to work in standard FEC mode.

<HUAWEI> system-view
[~HUAWEI] interface GigabitEthernet 0/1/0
[~HUAWEI-GigabitEthernet0/1/0] fec standard