Enterasys Networks FN 100 - Manual (Page 36)

The FN100 Chassis View
2-20 Managing the Hub
a MAC layer packet formation problem, or from a cabling problem that is
corrupting or losing data.
FCS
The number of frames received on a particular interface that are an integral
number of bytes in length, but do not pass the FCS (Frame Check Sequence)
check. FCS, or Frame Check Sequence, errors occur when packets are somehow
damaged on transit. When each packet is transmitted, the transmitting interface
computes a frame check sequence (FCS) value based on the contents of the packet,
and appends that value to the packet. The receiving interface performs the same
computation; if the FCS values differ, the packet is assumed to have been
corrupted and is counted as an FCS error.
SQE Test
Displays the number of times that the SQE Test Error message is generated by the
PLS sublayer on the selected interface. The SQE (Signal Quality Error) Test tests
the collision detect circuitry after each transmission. If the SQE Test fails, a SQE
Test Error is sent to the interface to indicate that the collision detect circuitry is
malfunctioning.
Carrier Sense
Displays the number of times that the carrier sense condition was lost or never
asserted when attempting to transmit a frame on a particular interface. Carrier
sense describes the action an interface desiring to transmit will take to listen to the
communication channel to see if any other interface is transmitting. If a “carrier is
sensed,” the sensing interface will wait a random length of time, and then attempt
to transmit.
Frame Too Long
Displays the amount of frames received on this interface that exceed the
maximum permitted frame size.
Internal MAC
The number of frames that failed to be received by the interface due to an internal
MAC sublayer receive error. These errors are only counted if a Frame Too Long,
Alignment, or FCS Error did not occur along with the internal MAC error.
Receive Errors
Displays the total number of receive errors of all types that were detected by the
selected interface while it was receiving a transmission.
Transmission Errors
Deferred
Displays the number of frames for which the first transmission attempt on this
interface is delayed because the medium is busy.