Compaq WL110, User Manual

Page: 68 / 144

6-8 Optimizing Performance
■
Retry Count - counts the number of frames that are lost (due to collisions)
during the initial transmission. During normal operation, the
Retry Count
should be less than 3% of the
Transmitted Fragment Count
.
■
Multiple Retry Count - counts the number of frames that are lost after the
initial transmission. During normal operation, the
Multiple Retry Count
will be
less than 3% of the
Retry Count
.
■
Failed Count - counts the number of frames that have reached the
Retry
Limit
. Failed frames will no longer attempt to re-transmit.
If the
Failed Count
is 1% or more of the
Multiple Retry Count
, your network may
be suffering from interference. Use the AP Manager Remote Link Test
Window (page 5-20) to look for either suddenly high noise figures, or low
SNR values, to find the cause of the interference.
Remote Statistics Tallies
Select the
Remote
tab in the monitor mode. Select either one of the interfaces
from the pull-down menu to display the statistics for the wireless network
interface(s). Then, use the following to diagnose link quality:
1. Compare the number of
In errors
with the number of
Bridge in packets
.
❏
When the number of “In errors” is 1% or more of the “Bridge in pack-
ets”, this may indicate that the wireless medium is very busy.
2. To verify this assumption, also compare the number of packets “Out errors”
with the number of “Bridge out packets”.
❏
When the number of
Out errors
is 1% or more of the
Bridge out packets
, it is
likely that one or more stations suffer form a poor link quality.
3. Compare the number of packets
Out collisions
with the number of
Bridge out
packets
.
❏
If the number of
Out collisions
is 1% or more of the
Bridge out packets
, it is
likely that the wireless medium is very busy. This might be caused by
many retransmitted frames, but it could also refer to many stations try-
ing to communicate at the same time.
4. You can also use the AP Manager remote link test to analyze whether one or
more stations show a poor link quality:
❏
When the poor link quality is caused by a low signal level, the station is
almost out of range of the Access Point.
❏
When the poor link quality is caused by a high noise level, there is a
source of interference in the signal path between the station and the
Access Point.
5. When one or more stations show a poor link quality, re-transmissions of
frames will disturb overall statistics and performance.
❏
You may be able to solve the problem by either moving the station(s) or
eliminating the source of interference.