Wireless/Redundant Edge Services xl Module Management and Configuration Guide WS.02.xx and greater

3-23
Radio Port Configuration
Configuring Radio Settings
Setting the Beacon Interval. A beacon is an 802.11 management frame
that is broadcast by an RP radio to advertise its presence as a network point
of access and to keep the network synchronized. Beacon frames include
information such as:
■ the service set identifier (SSID) for a WLAN
■ the RP radio’s basic SSID (BSSID) (media access control [MAC] address)
■ the broadcast destination address
■ a time stamp for synchronization
■ indicators about traffic and delivery, such as DTIMs
To let stations sleep longer and preserve battery life, you can increase the
time between beacons. Decreasing the beacon interval, on the other hand,
helps to support streaming multicast audio and video applications that are
jitter-sensitive.
To adjust the default beacon interval for radios in your network, complete
these steps:
1. Select Network Setup > Radio Adoption Defaults and click the
Configuration tab.
2. Select the radio type and click the Edit button.
3. In the Advanced Properties section, enter a value in the Beacon Interval field.
This value determines the time that the radio allows between sending
beacons. You specify the beacon interval in units of 1,000 ms. The default
setting is 100,000 ms.
4. Click the OK button.
Setting the DTIM Period. The DTIM is a known string of bits that can be
sent in a beacon frame. The DTIM notifies wireless stations using power save
that the RP has buffered broadcast or multicast frames that it will be sending
soon. DTIMs are simple data frames that do not require an acknowledgement,
so stations sometimes miss them. To overcome this, RPs are configured to
send periodic DTIMs out on beacons until the data is sent.
To allow wireless stations to sleep longer between transmissions, you can
increase the number of beacons between DTIMs. This helps to preserve
battery life for the wireless station. However, spacing DTIMs further apart
increases the chance that a station may miss the DTIM, which can cause
increased jitter and delay. To support streaming multicast audio and video or
other jitter-sensitive applications, you can decrease the number of beacons
between DTIMs.
The default DTIM period on all BSSIDs is 2 beacons.