HP Virtual Connect 8Gb 20-port Fibre Channel Module for c-Class BladeSystem - Manual (Page 186)

Virtual Connect modules 186
Port Statistic Description
EtherStatsCollisions
The best estimate of the total number of collisions on this Ethernet segment.
The value returned depends on the location of the RMON probe. Section
8.2.1.3 (10BASE-5) and section 10.3.1.3 (10BASE-2) of IEEE standard
802.3 states that a station must detect a collision, in the receive mode, if
three or more stations are transmitting simultaneously. A repeater port
must detect a collision when two or more stations are transmitting
simultaneously. Therefore, a probe placed on a repeater port could
record more collisions than a probe connected to a station on the same
segment would. Probe location plays a much smaller role when
considering 10BASE-T.
14.2.1.4 (10BASE-T) of IEEE standard 802.3 defines a collision as the
simultaneous presence of signals on the DO and RD circuits (transmitting
and receiving at the same time). A 10BASE-T station can only detect
collisions when it is transmitting. Therefore, probes placed on a station
and a repeater should report the same number of collisions. Additionally,
an RMON probe inside a repeater should ideally report collisions
between the repeater and one or more other hosts (transmit collisions as
defined by IEEE 802.3k) plus receiver collisions observed on any coax
segments to which the repeater is connected.
EtherStatsCRCAlignErrors The total number of packets received that had a length (excluding framing
bits, but including FCS octets) of between 64 and 1518 octets, inclusive,
but had either a bad FCS with an integral number of octets (FCS Error) or
a bad FCS with a non-integral number of octets (Alignment Error).
TXNoErrors
All packets transmitted without errors, less oversized packets.
RXNoErrors All packets received without errors, less oversized and undersized
packets.
Dot3StatsAlignmentErrors
A count of frames received on a particular interface that are not an
integral number of octets in length and do not pass the FCS check. The
count represented by an instance of this object is incremented when the
alignmentError status is returned by the MAC service to the LLC (or other
MAC user). According to the conventions of IEEE 802.3 Layer
Management, received frames for which multiple error conditions are
obtained are counted exclusively according to the error status presented
to the LLC. This counter does not increment for 8-bit wide group encoding
schemes.
Dot3StatsFCSErrors A count of frames received on a particular interface that are an integral
number of octets in length but do not pass the FCS check. This count does
not include frames received with a frame-too-long or frame-too-short error.
The count represented by an instance of this object is incremented when
the frameCheckError status is returned by the MAC service to the LLC (or
other MAC user). According to the conventions of IEEE 802.3 Layer
Management, received frames for which multiple error conditions are
obtained are counted exclusively according to the error status presented
to the LLC. Coding errors detected by the physical layer for speeds above
10 Mb/s cause the frame to fail the FCS check.
Dot3StatsSingleCollisionFrames A count of successfully transmitted frames on a particular interface for
which transmission is inhibited by exactly one collision. A frame that is
counted by an instance of this object is also counted by the corresponding
instance of either the ifOutUcastPkts, ifOutMulticastPkts, or
ifOutBroadcastPkts, and is not counted by the corresponding instance of
the dot3StatsMultipleCollisionFrames object. This counter does not
increment when the interface is operating in full-duplex mode.