Performing Advanced Configuration
SYSTIMAX® AirSPEED™ AP542
User Guide
45
If ACS is disabled, only channels in the lower frequency band are available for use:
•
36: 5.18 GHz (default)
•
40: 5.200 GHz
•
44: 5.220 GHz
•
48: 5.240 GHz
Affected Countries
The following countries are certified in the ETSI regulatory domain for operation in the 5 GHz band:
RTS/CTS Medium Reservation
The 802.11 standard supports optional RTS/CTS communication based on packet size. Without RTS/CTS, a sending
radio listens to see if another radio is already using the medium before transmitting a data packet. If the medium is
free, the sending radio transmits its packet. However, there is no guarantee that another radio is not transmitting a
packet at the same time, causing a collision. This typically occurs when there are hidden nodes (clients that can
communicate with the Access Point but are out of range of each other) in very large cells.
When RTS/CTS occurs, the sending radio first transmits a Request to Send (RTS) packet to confirm that the medium
is clear. When the receiving radio successfully receives the RTS packet, it transmits back a Clear to Send (CTS)
packet to the sending radio. When the sending radio receives the CTS packet, it sends the data packet to the receiving
radio. The RTS and CTS packets contain a reservation time to notify other radios (including hidden nodes) that the
medium is in use for a specified period. This helps to minimize collisions. While RTS/CTS adds overhead to the radio
network, it is particularly useful for large packets that take longer to resend after a collision occurs.
RTS/CTS Medium Reservation is an advanced parameter and supports a range between 0 and 2347 bytes. When set
to 2347 (the default setting), the RTS/CTS mechanism is disabled. When set to 0, the RTS/CTS mechanism is used for
all packets. When set to a value between 0 and 2347, the Access Point uses the RTS/CTS mechanism for packets that
are the specified size or greater. You should not need to enable this parameter for most networks unless you suspect
that the wireless cell contains hidden nodes.
Wireless Service Status
The user can shut down (or resume) the wireless service on the wireless interface of the AP through the CLI, HTTP, or
SNMP interface. When the wireless service on a wireless interface is shut down, the AP will:
•
Stop the AP services to wireless clients connected on that wireless interface by disassociating them
•
Disable the associated BSS port on that interface
•
Disable the transmission and reception of frames on that interface
•
Indicate the wireless service shutdown status of the wireless interface through LED and traps
•
Enable Ethernet interface so that it can receive a wireless service resume command through CLI/HTTP/SNMP
interface
NOTE
WSS disables only BSS ports; WDS ports are still operational.
NOTE
The wireless service cannot be shutdown on an interface where Rogue Scan is enabled.
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Austria
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Belgium
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Brazil
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Cyprus
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Denmark
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Estonia
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Finland
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France
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Germany
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Greece
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Iceland
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Ireland
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Italy
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Latvia
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Lithuania
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Luxembourg
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Malta
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Netherlands
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Norway
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Poland
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Portugal
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Saudi Arabia
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Spain
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Sweden
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Switzerland
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UK