Brocade Fabric OS Command Reference (Supporting Fabric OS v7.3.0) - Manual (Page 776)

746 Fabric OS Command Reference
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portCfgFec
2
portCfgFec
Enables or disables Forward Error Correction (FEC) or FEC through Transmitter Training Signal (TTS)
on 16 Gbps and 10 Gbps Fibre Channel links.
SYNOPSIS
portcfgfec --enable [-FEC] [-TTS] [slot/]port [-port]
portcfgfec --disable [-FEC] [-TTS] [slot/]port [-port]
portcfgfec --show [slot/]port [-port]
portcfgfec --help
DESCRIPTION
Use this command to enable or disable Forward Error Correction (FEC) or Transmitter Training Signal
(TTS) on a specified port or on a range of ports, or to display the configuration.
FEC provides a mechanism for reducing error rates during data transmissions over 16 Gbps Fibre
Channel links. When FEC is enabled on a port, the sender adds systematically generated
error-correcting code (ECC) to its data transmission. This mechanism allows the receiver to detect and
correct errors without needing to get additional information from the sender.
By default, TTS is disabled switch-wide on all 16 Gbps platforms. If the TTS mode is enabled, the port
negotiates FEC through TTS. The 16 Gbps TTS is not compatible with the more commonly used 16
Gbps 64B/66B. Thus, the TTS mode should only be enabled if a similarly TTS-capable and enabled
device is connected to the port.
The Brocade implementation of FEC is supported on 16 Gbps platforms and enables the switch to
recover bit errors in 16 Gbps and 10 Gbps data streams. The FEC encoding can correct one burst of up
to 11 error bits in every 2,112-bit transmission. The error correction covers both frames and primitives.
There is no loss of bandwidth or added transmission data rate overhead to the 16 Gbps FC link.
By default, FEC is enabled switch-wide on all 16 Gbps platforms. If FEC is already enabled on the ports,
enabling FEC has no effect. If a range of ports is specified, some of which are already in the requested
configuration, a notification is generated, and no action is taken for those ports only. All other ports in the
specified range are updated. Enabling or disabling FEC is disruptive to traffic.
When used with the --show option, the command displays the following information for the specified
ports:
Port
The port index number
FEC Capable
Displays YES if the port supports FEC. Displays NO if the port does not support
FEC.
FEC Configured
Displays ON if FEC is enabled on the port (default). Displays OFF if the feature is
disabled.
FEC via TTS Configured
Displays OFF if TTS is disabled on the port (default). Displays ON if the FEC
negotiation via TTS feature is enabled.
FEC State
The FEC state can be active or inactive. An active FEC state indicates that FEC is
enabled and actually running. An inactive state can indicate two conditions: FEC
is enabled, but not running due to some error condition (for example, FEC may
not be enabled on both links). Or FEC is disabled and therefore inactive.