Testing Data Throughput Efficiency - Cabletron Systems RoamAbout Access Point Manual

Testing Data Throughput Efficiency

Testing Data Throughput Efficiency
This procedure requires the RoamAbout Client Utility on a RoamAbout client. For
information about a client utility window, press <F1> while in that window.
1. Start the RoamAbout Client Utility by clicking Start from the Taskbar then selecting
Programs → RoamAbout → RoamAbout Client Utility. Click the More button if the
Status/Functions window is not displayed.
2. Select Link Test from the Status/Functions window.
If connected to an infrastructure network, the test partner is the associated Access
Point. If configured for an ad-hoc network, select another client in the network to be
the test partner then select the Test Results tab.
3. Check the Total Messages column. Data throughput efficiency is measured in
messages sent, lost, or received.
4. Divide the number of Messages Lost by the number of Messages Sent. The Messages
Sent number must be greater than 200.
Typically, the number of Messages Lost is less than 1 percent of the number of
Messages Sent. If this number increases to 5 percent, you may have communication
problems. If necessary, click the Reset button to observe only the current data
throughput.
If the SNR is low and the number of messages lost is high, the problem is likely due to a
poor communications quality. For example, the client and the test partner are too far apart
or the connection suffers from a source of noise interference. Check the communications
quality as described in "Testing Radio Communications Quality" section on page 6-2.
If the SNR is adequate or good but there is a relatively large number of messages lost or
received after a retry, the problem might indicate:
•
A very busy network where many clients try to access the medium at the same time.
•
A microwave oven in close vicinity (7 to 10 feet) to the client or Access Point is
causing short bursts of interference. This noise might not be displayed by the noise
level indicator, but could still be forcing the clients to retransmit frames.
•
Another client is suffering from a poor communications quality and is consequently
sending many retransmissions.
•
Numerous frame collisions are occurring due to a hidden station problem.
Run the RoamAbout Client Utility link test from multiple clients to determine if the
problem is local (one client only) or experienced by all clients.
6-4 Maintaining the Wireless Network