User guide

Optimizing Performance
6-9
Alvarion
Important indicators to monitor on the Remote Link Test window are:
! Signal to noise ratio (SNR) for an overview of the radio link quality.
! Signal level to determine whether a poor SNR is related to a weak radio
signal (i.e. a station is “out-of-range”).
! Noise level to determine whether a poor SNR is related to a source of
interference.
IEEE Information
The IEEE information on the
IEEE 802.11 tab in the monitor mode allows you to
track frame activity on the IEEE interface of the Base Station.
Figure 6-23: IEEE information tab
The three indicators that you should pay particular attention to are:
! 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 on page 5-22 to look for either suddenly high noise figures, or low
SNR values, to find the cause of the interference.