Select the role in the radio network for each device. Depending on which device you are using, the roles can vary. You can also configure a fallback role for root access points. The wireless device automatically assumes the fallback role when its Ethernet port is disabled or disconnected from the wired LAN. Choose one of the three access point (root)
settings if the access point is connected to the wired LAN.
Data Rates
Use the data rates setting to choose the
data transmission rates. The rates are expressed in megabits
per second. The device always attempts to transmit at the
highest rate selected. If there are obstacles or interference,
the device steps down to the highest rate that enables data
transmission.
Click the Best Range button
to optimize access point range or the Best Throughput button
to optimize throughput.
Note: When you configure the 802.11g access point radio for best throughput,
the access point sets all 802.11g data rates to basic (required).
This setting blocks association from 802.11b client devices.
For each of the rates, choose Require,
Enable, or Disable.
-
Require - Enables transmission at this rate for all packets, both unicast
and multicast. At least one data rate must
be set to Require. A client must support a
required rate before it can associate.
-
Enable - Enables transmission at this rate for unicast packets only.
-
Disable
- Does not allow
transmission at this rate.
Note: The
client must support the basic rate you select or it cannot
associate with the access point.
Transmitter Power (mW)
This setting determines the power level of
the radio transmission. The default power setting is the highest
transmit power allowed in your regulatory domain.
Note: Government
regulations define the highest allowable power level for radio
devices. This setting must conform to established standards
for the country in which you use the device.
To reduce interference, limit the range of
your access point, or to conserve power, select a lower power
setting.
For an 802.11g radio, the Transmit Power setting is divided
into CCK Transmitter Power (mW) and OFDM Transmitter Power (mW). CCK is the
modulation used in 802.11g for the lower frequency rates,
and OFDM is the modulation used in 802.11g for higher data
rates (above 20 Mbps).
Note: The 100-mW (20-dBM) value is not available for rates greater than
12 Mbps.
Power Translation Table (mW/dBm)
The power settings may be in mW or in dBm
depending on the particular radio that is being configured.
This table translates both mW and dBm.
Limit Client Power (mW)
Determine the maximum power level allowed
on client devices that associate to the access point. When
a client device associates to the access point, the access
point sends the maximum power level setting to the client.
Note: The 100 mW value is not available for rates greater than 12 Mbps.
Default Radio Channel
The available selection of radio channels
is determined by your regulatory domain. The default setting
is the least-congested frequency. With this setting, the device
scans for the radio channel that is least busy and selects
that channel for use. The device scans at power-up and when
the radio settings are changed. You can also select specific
channel settings from the Default Radio Channel drop-down
menu.
Note: Access points with
5-GHz radios configured at the factory for use in Europe now
comply with European Union regulations that require radio
devices to use Dynamic Frequency Selection (DFS) to detect
radio signals and avoid interfering with them. Radios configured
for use in other regulatory domains do not use DFS. If DFS
is enabled, the frequency is automatically selected, and the
ability to choose a channel is disabled.
Least Congested Channel Search
This selection list is available only when
Default Radio Channel is set to Least Congested Frequency.
You can search for least congested channels but exclude some
channel(s) which are known to be problematic or already in
use by other applications. By default, all channels are selected
and searched. To select more than one channel, hold down the
Ctrl or Shift keys to highlight multiple channels.
World Mode Multi-Domain Operation (for 802.11b and 802.11g only)
World mode operation is disabled by default.
If you uncheck Disable, the device adds channel carrier
set information to its beacon. Client devices with world-mode
enabled receive the carrier set information and adjust their
settings automatically. If you select the dot11d option,
you must enter an ISO country code. If you select the legacy
option, you enable Cisco legacy world mode.
With world mode enabled, the access point
advertises the local settings, such as allowed frequencies
and transmitter power levels. Clients with this capability
then passively detect and adopt the advertised world settings,
and then actively scan for the best access point.
Country Code (required only for dot11d option)
A country code can be selected only if the
dot11d option was chosen in the World Mode option above. Use
the drop-down menu to select the appropriate country. After
the country code, you must enter indoor or outdoor
to indicate the placement of the access point.
Radio Preamble
(802.11b and 802.11g only)
The radio preamble is a section of data at
the head of a packet and contains information the access
point and the client devices need when sending and receiving
packets. Keep the setting on short unless you want
to test with long preambles. If you have the radio preamble
set to short and a client associates that does not support
short preamble associates, the access point will send only
long preamble packets to this client.
-
Short - A short preamble improves throughput performance. Cisco Aironet's
wireless LAN adapter supports short preambles. The access
point and client negotiate the use of the short preamble.
Early models of Cisco Aironet's wireless LAN adapter require
long preambles.
-
Long - A long preamble ensures compatibility between the access point
and all early models of Cisco Aironet wireless LAN adapters.
Receive Antenna
and Transmit Antenna
-
Diversity
- This default setting tells the
device to use the antenna that receives the best signal.
If your device has two fixed (non-removable) antennas,
you should use this setting for both receive and transmit.
-
Left (secondary)- If your device has removable antennas and you install a high-gain
antenna on the left connector, you should use this setting
for both receive and transmit. When you look at the back
panel, the left antenna is on the left.
- Right (primary)-
If your device has removable antennas and you install a high-gain
antenna on the right connector, you should use this setting
for both receive and transmit. When you look at the back
panel, the right antenna is on the right.
Note: The
device receives and transmits using only one antenna at a
time, so you cannot increase range by installing high-gain
antennas on both connectors and pointing one north and one
south. When the device uses the north-pointing antenna, client
devices to the south should be ignored by the access point.
External Antenna Configuration
This feature is currently not operational,
but it may be supported in future releases.
Antenna Gain(dB)
The gain of an antenna is a measure of the
antenna's ability to direct or focus radio energy over a region
of space. High-gain antennas have a more focused radiation
pattern in a specific direction. This setting is disabled
on the bridge.
Gratuitous Probe Response (GPR)
GPR aids in conserving battery power in dual mode phones that support cellular and WLAN modes of operation. GPR is available on 5-GHz radios and is disabled by default. You can configure two GPR settings:
- Period - This setting determines the time between GPR transmissions in Kusec intervals from 10 to 255 (similar to the beacon period)
- Speed - The speed is the data rate used to transmit the GPR
Selecting a longer period reduces the amount of RF bandwidth consumed by the GPR with the possibility of shorter battery life. Selecting higher transmission speeds also reduces the amount of bandwidth consumed but at the expense of a smaller cell size.
Aironet Extensions
Select Enable to use Cisco Aironet
802.11 extensions. This setting must be set to Enable so that
you can use load balancing, MIC, and TKIP.
Ethernet Encapsulation Transform
Choose 802.1h or RFC1042 to
set Ethernet encapsulation type. Data packets that are not
802.2 packets must be formatted to 802.2 with 802.1h or RFC1042.
Cisco Aironet equipment defaults to RFC1042 because it provides
optimum interoperability.
-
802.1h - This setting provides optimum performance for Cisco Aironet wireless
products.
-
RFC1042 - Use this setting to ensure interoperability with non-Cisco Aironet
wireless equipment. RFC1042 does not provide the interoperability
advantages of 802.1h but is used by other manufacturers
of wireless equipment.
Reliable Multicast to WGB
Normally, an access point treats a workgroup
bridge as an infrastructure device and not as a client. The
access point uses the reliable multicast protocol to ensure
delivery of all multicast packets. The extra traffic caused
by reliable delivery limits the number of workgroup bridges
that can be associated. Select Disable to allow the
workgroup bridge to be treated as a non-infrastructure device
and thus allow the maximum number of workgroup bridges to
be associated.
Public Secure Packet Forwarding
Public Secure Packet Forwarding (PSPF) prevents
client devices associated to an access point from inadvertently
sharing files or communicating with other client devices associated
to the access point. It provides Internet access to client
devices without providing other capabilities of a LAN.
No exchange of unicast, broadcast, or multicast
traffic occurs between protected ports. Choose Enable
so that the protected port can be used for secure mode configuration.
PSPF must be set per VLAN.
Note: To prevent communication
between clients associated to different access points on your
wireless LAN, you must set up protected ports on the switch
to which your access points are connected.
Short Slot Time
When you enable short slot time, only the wireless devices with clients associated to the 802.11g, 2.4-GHz radio support slot time. Enabling short slot time increases throughput on the 802.11g, 2.4-GHz radio.
Beacon Period
The amount of time between beacons in kilomicroseconds.
One Kusec equals 1,024 microseconds.
Data Beacon Rate
(DTIM)
This setting, always
a multiple of the beacon period, determines how often the
beacon contains a delivery traffic indication message (DTIM).
A traffic indication map is present in every beacon. The DTIM
notifies power-save client devices that a packet is waiting
for them. If power save clients are active, the access point
buffers any multicast traffics and delivers them immediately
after the DTIM beacon. Power save nodes always wake for the
DTIM beacons. The longer the time, the more buffering the
access point does, and the longer the multicasts are delayed.
If the beacon period
is set at 100 (its default setting), and the data beacon rate
is set at 2 (its default setting), then the device sends a
beacon containing a DTIM every 200 Kusec. One Kusec equals
1,024 microseconds.
Max. Data Retries
The maximum number of attempts the
device makes to send a packet before giving up, dropping the
packet, and disassociating the client.
RTS Max. Retries
The maximum number of times the device
issues an RTS before stopping the attempt to send the packet
through the radio. Enter a value from 1 to 128.
Fragmentation Threshold
This setting determines the size at
which packets are fragmented (sent as several pieces instead
of as one block). Use a low setting in areas where communication
is poor or where there is a great deal of radio interference.
RTS Threshold
This setting determines the packet
size at which the device issues a request to send (RTS) before
sending the packet. A low RTS Threshold setting can be useful
in areas where many client devices are associating with the
access point or in areas where the clients are far apart and
can detect only the access point and not each other.
Repeater
Parent AP Timeout
If this timeout is enabled, the access point
in repeater mode looks only for the parent access point specified
in the following Repeater Parent AP MAC definition for this
given amount of time. If the timeout expires, the list is
ignored, and the unit associates to an access point that matches
its requirements, regardless of its MAC address. If the timeout
is disabled, the repeater associates only to parents in the
list and continues the search.
Repeater Parent
AP MAC 1-4
Normally, a repeater access point (without
a wired LAN connection) associates much like a normal client,
choosing the best access point it can find. Enter MAC addresses
in this list if you want to control the parent access point
to which a repeater may associate. If MAC addresses are entered
in this list, a repeater associates only to a parent whose
MAC address matches an entry in the list. If the first MAC
address is not available, the access point continues through
the list and waits the amount of time specified in Repeater
Parent AP Timeout field before trying the next.
See Also:
Services: VLAN