HP Virtual Connect 1.10Gb-F Ethernet Module for c-Class BladeSystem User Manual

Page 204

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Port Statistic

Description

EtherStatsOversizePkts

The total number of packets received that were longer than 1518 octets
(excluding framing bits, but including FCS octets) and were otherwise

well-formed.

EtherStatsJabbers

The total number of packets received that were longer than 1518 octets
(excluding framing bits, but including FCS octets), and 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). This definition of jabber
is different than the definition in IEEE-802.3 section 8.2.1.5 (10BASE5)

and section 10.3.1.4 (10BASE2). These documents define jabber as

the condition where any packet exceeds 20 ms. The allowed range to
detect jabber is between 20 ms and 150 ms.

EtherStatsOctets

The total number of octets of data (including those in bad packets)

received on the FCS octets). This object can be used as a reasonable
estimate of Ethernet utilization. If greater precision is required, the

StatsPkts and StatsOctets objects should be sampled before and after a

common interval. The differences in the sampled values are Pkts and
Octets, respectively, and the number of seconds in the interval is

Interval. These values are used to calculate the Utilization as follows:

Utilization = [(Pkts * (9.6 + 6.4) + (Octets * .8)) / (Interval * 10,000)].
The result of this equation is the value Utilization which is the percent

utilization of the Ethernet segment on a scale of 0 to 100 percent.

EtherStatsPkts

The total number of packets (including bad packets, broadcast packets,
and multicast packets) received.

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.

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