Wireless/Redundant Edge Services xl Module Management and Configuration Guide WS.01.03 or greater

5-21
Radio Port Configuration
Configuring Radio Settings
might alter this setting to ensure that the same module adopts all RPs in the
same area. Wireless Edge Services xl Module preferentially adopts RPs that
have the same ID as the module itself.
Note Having two active members in a redundancy group is not a standard configu-
ration. If your module in not part of a redundancy group, or if its redundancy
group includes one active and one standby member, you should leave the
adoption preference ID at the default, 0.
To set the adoption preference ID for all RP radios that this module adopts,
follow these directions:
1. Select Network Setup > Radio Adoption Defaults > Configuration, select
the radio type, and click Edit.
2. In the Adoption Preference ID box, enter a preference ID number between
1 and 65535. (The default is 1.)
Set a matching adoption preference ID on the module that should adopt
these RPs when the are installed in their final location. (Click Global
Settings in the Network Setup > Radio screen to set the ID.)
3. Click OK.
To force another module to adopt a particular radio, change the radio’s
preference ID to the ID on that second module, as explained in “Configuring
Advanced Properties for a Particular Radio” on page 5-36.
Enabling Support for a Short Preamble. As part of the 802.11 standards,
stations and radios are required to prepend a preamble to transmitted frames.
A preamble is a known string of bits that signals the destination device to
prepare to receive data, and alerts all devices sharing a common channel that
a data transmission is beginning.
There are two types of preambles: a long preamble and a short preamble. It
takes a maximum of 192 ms to process the long preamble and 96 ms to process
the short preamble. Because the short preamble yields about 50-percent
savings in frame overhead, it can improve the throughput of a network,
particularly one transmitting traffic such as VoWLAN and streaming video
frames.
However, not all devices support the short preamble. In addition, the short
preamble is only supported in 802.11g mode: you cannot configure this option
on 802.11a radios.