Specifications

OmniAccess Reference: AOS-W System Reference
598 Part 031652-00 May 2005
z Reset the client NIC. If an internal error has caused the dropped associa-
tion, a reset of the NIC may restore connectivity.
Client experiences poor performance
This scenario covers many different situations. In general, the complaint will
be slow performance – download speeds may be low, application timeouts
may occur, or general sluggishness may be reported.
z If the performance problems began while the user was moving, it is possi-
ble that roaming failed. Examine the client’s current signal strength and
data rate. If they are low, compare the user’s physical location with the
location of the currently associated AP. This is sometimes caused by an
issue known as “client stickiness” – the tendency for a client to maintain an
existing association and ignore closer APs even when signal strength has
significantly degraded. Ideally, pre-deployment testing will identify client
NICs and drivers that exhibit this problem so that they can be excluded
from the deployment.
z Examine client statistics from the Alcatel management GUI. Navigate to
Monitoring > Clients > Enterprise Clients, select the affected client, and click
on “Client Activity”.
z If RSSI – also known as signal strength - is low (below 20), the client
has poor signal strength to the nearest AP. This may indicate a roaming
failure, described above.
z If “transmit retries” is high, the client is sending frames that are not
being acknowledged by the AP. The client is then forced to re-transmit
these frames, reducing performance. The cause may be interference or
low signal strength.
z If “receive retries” is high, the AP is sending frames that are not being
acknowledged by the client. The AP is then forced to re-transmit these
frames, reducing performance. The cause may be interference or low
signal strength.
z If the transmit or receive data rate is low, it indicates that the client or
AP’s rate adaptation algorithm has detected errors at higher data rates
and is forcing a lower rate. This could indicate interference or low sig-
nal strength.
z If signal strength is high, retry rate is high, and data rate is low, the
cause may be localized interference. These symptoms indicate a client
that is close to the AP with good signal strength, but with poor commu-
nication between the AP and client. Examine the Events tab in the GUI
and look for any indications of detected interference.