User`s guide

MOP Counters

The following counters are kept for the Ethernet boot channel. All counters are

unsigned integers. V4 counters rollover on overﬂow. All V3 counters "latch"

at their maximum value to indicate overﬂow. Unless otherwise stated, all

counters include both normal and multicast trafﬁc. Furthermore, they include

information for all protocol types. Frames received and bytes received counters

do not include frames received with errors. Table F–1 displays the byte lengths

and ordering of all the counters in both MOP Versions 3.0 and 4.0.

Table F–1 MOP Counter Block

V3 V4

Name Off Len Off Len Description

TIME_SINCE_CREATION 00 2 00 16 Time since last zeroed. The

time which has elapsed, since the

counters were last zeroed. Provides

a frame of reference for the other

counters by indicating the amount

of time they cover. For MOP V3,

this time is the number of seconds.

MOP V4 uses the UTC Binary

Relative Time format.

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MOP Counters F–1