Table 18: Fault finder sensitivities for supported conditions
Condition
triggering
fault finder
Sensitivities
Units (in
packets)
Time period
Fault finder
reacts:
High
Medium
Low
Bad driver —
Too many
under-sized
packets or too
many giant
packets
6
21
36
1/10,000
Incoming
20 secs
If (undersized/
total) >=
(sensitivity/
10,000)OrIf
(giant/total) >=
(sensitivity/
10,000)
Bad
transceiver —
Excessive
jabbering -
Jabbers:
(Jabbers are
packets
longer than
the MTU) -
Fragments:
(packets
shorter than
they should
be)
65
2110
3614
1/10,000
IncomingOne
Fragments
20 secs20
secs
If (jabbers/
total) >=
(sensitivity/
10,000)Or If
fragment
count in the
last 20
seconds >=
sensitivity
Bad cable —
Excessive
CRC/
alignment
errors
6
21
36
1/10,000
Incoming
20 secs
If (CRC and
alignment
errors/ total)
>= (sensitivity/
10,000)
Too Long
Cable —
Excessive late
collisions (a
late collision
error occurs
after the first
512 bit times)
6
21
36
1/10,000
Outgoing
20 secs
If (late
collisions/
total) >=
(sensitivity/
10,000)
Table Continued
Chapter 6 Port Traffic Controls
181