3Com WXR100 3CRWXR10095A, WX4400 3CRWX440095A manual Set radio-profile name max-tx-lifetime time

244CHAPTER 10: CONFIGURING MAP ACCESS POINTS

Changing the Maximum Transmit Threshold The maximum transmission threshold specifies the number of milliseconds a frame scheduled to be transmitted by a radio can remain in buffer memory. To change the maximum transmit lifetime, use the following command:

set radio-profile name max-tx-lifetime time

The time can be from 500 ms (0.5 second) through 250,000 ms (250 seconds). The default is 2000 ms (2 seconds).

To change the maximum transmit threshold for radio profile rp1 to

4000 ms, type the following command:

WX1200# set radio-profile rp1 max-tx-lifetime 4000 success: change accepted.

Changing the Preamble Length By default, 802.11b/g radios advertise support for frames with short preambles and can support frames with short or long preambles.

An 802.11b/g radio generates unicast frames to send to a client with the preamble length specified by the client. An 802.11b/g radio always uses a long preamble in beacons, probe responses, and other broadcast or multicast traffic.

Generally, clients assume access points require long preambles and request to use short preambles only if the access point with which they are associated advertises support for short preambles. You can disable the advertisement of support for short preambles by setting the preamble length value to long. In this case, clients assume that the access point supports long preambles only and the clients request long preambles.

Changing the preamble length value affects only the support advertised by the radio. Regardless of the preamble length setting (short or long), an 802.11b/g radio accepts and can generate 802.11b/g frames with either short or long preambles.

If any client associated with an 802.11b/g radio uses long preambles for unicast traffic, the MAP still accepts frames with short preambles but does not transmit any frames with short preambles. This change also occurs if the access point overhears a beacon from an 802.11b/g radio on another access point that indicates the radio has clients that require long preambles.