NS3000/iX Operations and Maintenance Reference Manual (36922-90042)

Appendix A 203
LINKCONTROL Command
NS 3000/iX 100VG-AnyLAN Link Statistics
Transmits dropped — Total number of frames the link driver
discarded because the transmit queue was full, or because the data to
be sent was fragmented beyond recognition. The maximum value of this
32-bit field is 2147483647. It would be unusual for this statistic to
contain a nonzero value.
Trans underruns — Total number of frames aborted by the adapter
card during transmission because the remaining data was not made
available to the transmit hardware fast enough. It indicates unexpected
latency on the dedicated internal bus onboard the adapter card. If this
condition occurs, the adapter will automatically adjust to improve the
latency, and retransmit the aborted frame automatically. The maximum
value of this 32-bit field is 2147483647. For this statistic, a value of less
than 3 would be considered normal.
Recv overruns — Total number of address-matched frames that could
not be received into the adapter card, either because prior data was not
being removed by the receive hardware fast enough, or because their
size exceeded the maximum frame size. May indicate unexpected
latency on the dedicated internal bus onboard the adapter card, which
cannot be automatically adjusted by the link driver. The maximum
value of this 32-bit field is 2147483647. It would be unusual for this
statistic to contain a nonzero value.
Recv deferred — Number of times an address-matched receive frame
was temporarily held (queued) by the link driver, because of a
momentary lack of DMA resources. Once those resources became
available, the frame was automatically transferred to the host. The
maximum printable value of this 64-bit field is 17 digits, or about 99
million billion frames. In the previous example, 123 frames were
temporarily held.
CRC or Maxsize error — Number of cyclic redundancy check (CRC)
errors or oversized frames that were seen during reception by the link.
A CRC error indicates that the frame was checked using CRC-32
frame-checking, but that the value obtained by the CRC did not match
the CRC value contained at the end of the frame. CRC errors do not
include frames having alignment or coding errors. Oversized frames are
those longer than 1518 bytes. These adapter card statistics are
periodically read, and are accumulated by the link driver. The
maximum value of this 32-bit field is 2147483647. A nonzero value in
this statistic could indicate a defective cable, adapter, or hub, a loose
connection, presence of severe electrical noise along the cable path, or a
misbehaving application, adapter, or hub at the transmission end.
Code or Align error — Number of frames received with an alignment
error (not an even multiple of 4 bits of data) or code errors (an error
signal was received from the 100VG-AnyLAN receive hardware). These
adapter card statistics are periodically read, and are accumulated by
the link driver. The maximum value of this 32-bit field is 2147483647. If