Appendix B Wireless LANs
NWA-3500/NWA-3550 User’s Guide
322
wireless gateway, but out-of-range of each other, so they cannot "hear" each
other, that is they do not know if the channel is currently being used. Therefore,
they are considered hidden from each other.
Figure 227
RTS/CTS
When station
A
sends data to the AP, it might not know that the station
B
is
already using the channel. If these two stations send data at the same time,
collisions may occur when both sets of data arrive at the AP at the same time,
resulting in a loss of messages for both stations.
RTS/CTS
is designed to prevent collisions due to hidden nodes. An
RTS/CTS
defines the biggest size data frame you can send before an RTS (Request To
Send)/CTS (Clear to Send) handshake is invoked.
When a data frame exceeds the
RTS/CTS
value you set (between 0 to 2432
bytes), the station that wants to transmit this frame must first send an RTS
(Request To Send) message to the AP for permission to send it. The AP then
responds with a CTS (Clear to Send) message to all other stations within its range
to notify them to defer their transmission. It also reserves and confirms with the
requesting station the time frame for the requested transmission.
Stations can send frames smaller than the specified
RTS/CTS
directly to the AP
without the RTS (Request To Send)/CTS (Clear to Send) handshake.
You should only configure
RTS/CTS
if the possibility of hidden nodes exists on
your network and the "cost" of resending large frames is more than the extra
network overhead involved in the RTS (Request To Send)/CTS (Clear to Send)
handshake.
If the
RTS/CTS
value is greater than the
Fragmentation Threshold
value (see
next), then the RTS (Request To Send)/CTS (Clear to Send) handshake will never
occur as data frames will be fragmented before they reach
RTS/CTS
size.
Note: Enabling the RTS Threshold causes redundant network overhead that could
negatively affect the throughput performance instead of providing a remedy.
Содержание 802.11a/g Wireless CardBus Card ZyXEL AG-120
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Страница 8: ...Safety Warnings NWA 3500 NWA 3550 User s Guide 8...
Страница 10: ...Contents Overview NWA 3500 NWA 3550 User s Guide 10...
Страница 20: ...Table of Contents NWA 3500 NWA 3550 User s Guide 20...
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Страница 34: ...Chapter 1 Introducing the NWA NWA 3500 NWA 3550 User s Guide 34...
Страница 52: ...Chapter 4 Management Mode NWA 3500 NWA 3550 User s Guide 52...
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Страница 146: ...Chapter 9 SSID Screen NWA 3500 NWA 3550 User s Guide 146...
Страница 160: ...Chapter 10 Wireless Security Screen NWA 3500 NWA 3550 User s Guide 160...
Страница 178: ...Chapter 14 IP Screen NWA 3500 NWA 3550 User s Guide 178...
Страница 186: ...Chapter 15 Rogue AP Detection NWA 3500 NWA 3550 User s Guide 186...
Страница 198: ...Chapter 16 Remote Management Screens NWA 3500 NWA 3550 User s Guide 198...
Страница 260: ...Chapter 21 Load Balancing NWA 3160 Series User s Guide 260...
Страница 264: ...Chapter 22 Dynamic Channel Selection NWA 3160 Series User s Guide 264...
Страница 276: ...Chapter 23 Maintenance NWA 3500 NWA 3550 User s Guide 276...
Страница 277: ...277 PART III Troubleshooting and Specifications Troubleshooting 279 Product Specifications 285...
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Страница 284: ...Chapter 24 Troubleshooting NWA 3500 NWA 3550 User s Guide 284...
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Страница 368: ...Appendix D Importing Certificates NWA 3500 NWA 3550 User s Guide 368...
Страница 386: ...Appendix F Text File Based Auto Configuration NWA 3500 NWA 3550 User s Guide 386...
Страница 396: ...Index NWA 3500 NWA 3550 User s Guide 396...