Brocade Fabric Watch Administrators Guide (Supporting Fabric OS v7.3.0) - Manual (Page 65)

Port Monitoring
● Port class areas.............................................................................................................. 65
● Port class guidelines and default settings....................................................................... 66
● Port configuration............................................................................................................ 69
● portThConfig command procedures................................................................................69
● Port fencing .................................................................................................................... 79
● Port health and CRC monitoring..................................................................................... 83
● Recommended port configuration settings......................................................................83
Port class areas
You can use the portThConfig command to configure the Port class. Port setting guidelines and
specific examples of portThConfig configurations are presented in subsequent sections.
NOTE
Fabric Watch monitors and reports the status of physical and virtual FC ports. Physical GbE ports and
iSCSI ports are not monitored and are not included in the Port Class area.
Port class areas TABLE 15
Area Description
Cyclic redundancy check
(CRC) The number of times an invalid cyclic redundancy check error occurs on a port or a
frame that computes to an invalid CRC. Invalid CRCs can represent noise on the
network. Such frames are recoverable by retransmission. Invalid CRCs can indicate
a potential hardware problem.
Invalid transmission words
(ITW) The number of times an invalid transmission word error occurs on a port. A word did
not transmit successfully, resulting in encoding errors. Invalid word messages
usually indicate a hardware problem.
NOTE
For Fabric OS 7.1.0 and later, the ITW counter includes a physical coding sublayer
(PCS) violation. ITW violations can occur due to an ITW violation, a PCS violation, or
both.
Class 3 discards
(C3TX_TO) The number of Class 3 discards frames because of time-outs.
Link loss (LOS) The number of times a link failure occurs on a port or sends or receives NOS. Both
physical and hardware problems can cause link failures. Link failures also frequently
occur due to a loss of synchronization or a loss of signal.
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