3Com 3CRWX120695A, Configuration Manual

Page: 242 / 728

242 C
HAPTER
10: C
ONFIGURING
MAP A
CCESS
P
OINTS
Changing the DTIM Interval The DTIM interval specifies the number
of times after every beacon that a radio sends a delivery traffic indication
map (DTIM). A MAP sends the multicast and broadcast frames stored in
its buffers to clients who request them in response to the DTIM. The
DTIM interval applies to both the beaconed SSID and the unbeaconed
SSID.
The DTIM interval does not apply to unicast frames. A MAP also stores
unicast frames in buffer memory, but the MAP includes information
about the buffered unicast frames in each beacon frame. When a user
station receives a beacon frame that advertises unicast frames destined
for the station, the station sends a request for the frames and the MAP
transmits the requested frames to the user station.
To change the DTIM interval, use the following command:
set radio-profile name dtim-interval interval
The interval can be a value from 1 through 31. The default is 1.
To change the DTIM interval for radio profile rp1 to 2, type the following
command:
WX1200# set radio-profile rp1 dtim-interval 2
success: change accepted.
Changing the RTS Threshold The RTS threshold specifies the
maximum length a frame can be before a radio uses the
Request-to-Send/Clear-to-Send (RTS/CTS) method to send the frame. The
RTS/CTS method clears the air of other traffic to avoid corruption of the
frame due to a collision with another frame.
When a frame is long enough for the RTS/CTS method to be applicable,
the radio sends a Request-To-Send (RTS) message addressed to the
intended receiver for the frame. The receiver replies with a Clear-To-Send
(CTS) message. When the radio receives the CTS message, the radio
transmits the frame and waits for an acknowledgment from the receiver.
The radio does not transmit additional frames until receiving the
acknowledgment.
Any other user station that overhears the RTS or CTS message stops
transmitting until the station overhears the acknowledgment message.