Installation guide

Network Setup
4-91
Adoption Preference
ID
Displays the preference ID of the switch.The value can be set
between 1 and 65535. To define the radios as preferred, the access
port preference ID should be same as adoption preference ID.
The adoption preference ID is used for AP load-balancing. A switch
will preferentially adopt APs which have the same adoption-
preference-ID as the switch itself.
Short Preambles only If using an 802.11bg radio, select this checkbox for the radio to
transmit using a short preamble. Short preambles improve
throughput. However, some devices (SpectraLink phones) require
long preambles. This checkbox does not display if using an 802.11a
radio.
RTS Threshold Specify a Request To Send (RTS) threshold (in bytes) for use by the
WLAN's adopted access ports.
RTS is a transmitting station's signal that requests a Clear To Send
(CTS) response from a receiving station. This RTS/CTS procedure
clears the air where many MUs are contending for transmission
time. Benefits include fewer data collisions and better
communication with nodes that are hard to find (or hidden) because
of other active nodes in the transmission path.
Control RTS/CTS by setting an RTS threshold. This setting initiates
an RTS/CTS exchange for data frames larger than the threshold,
and sends (without RTS/CTS) any data frames smaller than the
threshold.
Consider the trade-offs when setting an appropriate RTS threshold
for the WLAN's access ports. A lower RTS threshold causes more
frequent RTS/CTS exchanges. This consumes more bandwidth
because of additional latency (RTS/CTS exchanges) before
transmissions can commence. A disadvantage is the reduction in
data-frame throughput. An advantage is quicker system recovery
from electromagnetic interference and data collisions.
Environments with more wireless traffic and contention for
transmission make the best use of a lower RTS threshold.
A higher RTS threshold minimizes RTS/CTS exchanges, consuming
less bandwidth for data transmissions. A disadvantage is less help
to nodes that encounter interference and collisions. An advantage
is faster data-frame throughput. Environments with less wireless
traffic and contention for transmission make the best use of a
higher RTS threshold. Default is 2346.
Beacon Interval Specify a beacon interval in units of 1,000 microseconds (K-us).
This is a multiple of the DTIM value, for example, 100: 10. (See
"DTIM Period," below). A beacon is a packet broadcast by the
adopted access ports to keep the network synchronized. Included
in a beacon is information such as the WLAN service area, the
radio-port address, the broadcast destination addresses, a time
stamp, and indicators about traffic and delivery such as a DTIM.
Increase the DTIM/beacon settings (lengthening the time) to let
nodes sleep longer and preserve battery life. Decrease these
settings (shortening the time) to support streaming-multicast audio
and video applications that are jitter-sensitive. The default is
100 K-us.