Cisco ONS 15454 SDH Procedure Manual page 796

DLP- D441 Create Ethernet RMON Alarm Thresholds
Table 21-2
Variable
dot3StatsCarrierSenseErrors
dot3StatsSQETestErrors
etherStatsBroadcastPkts
etherStatsCollisions
Cisco ONS 15454 SDH Procedure Guide, R7.0
21-30
Ethernet Threshold Variables (MIBs) (continued)
Definition
(G-Series only) The number of transmission errors on a
particular interface that are not otherwise counted.
(G-Series only) A count of times that the SQE TEST ERROR
message is generated by the physical signaling sublayer (PLS)
sublayer for a particular interface.
The total number of good packets received that were directed to
the broadcast address. This does not include multicast packets.
An 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 (10Base5) and Section 10.3.1.3
(10Base2) of IEEE 802.3 state 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. Thus, a probe placed on a repeater port could
record more collisions than a probe connected to a station on the
same segment.
Probe location plays a much smaller role when considering
10BaseT. Section 14.2.1.4 (10BaseT) of IEEE 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
10BaseT station can only detect collisions when it is
transmitting. Thus, probes placed on a station and a repeater
should report the same number of collisions.
An RMON probe inside a repeater should 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.
Chapter 21 DLPs D400 to D499
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