3com WX1200 3CRWX120695A Manual De Usuario

C

HAPTER

 10: C

ONFIGURING

 MAP A

CCESS

 P

OINTS

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.

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.