ZyWALL 5 User’s Guide
574
Appendix F
Figure 26
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.
Fragmentation Threshold
A
Fragmentation Threshold
is the maximum data fragment size (between 256 and 2432
bytes) that can be sent in the wireless network before the AP will fragment the packet into
smaller data frames.
Содержание ZyXEL ZyWALL 5
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Страница 86: ...ZyWALL 5 User s Guide 84 Chapter 3 Wizard Setup ...
Страница 96: ...ZyWALL 5 User s Guide 94 Chapter 4 LAN Screens ...
Страница 102: ...ZyWALL 5 User s Guide 100 Chapter 5 Bridge Screens ...
Страница 130: ...ZyWALL 5 User s Guide 128 Chapter 7 WAN Screens Figure 45 WAN PPPoE Encapsulation ...
Страница 138: ...ZyWALL 5 User s Guide 136 Chapter 7 WAN Screens Figure 50 Dial Backup Setup ...
Страница 144: ...ZyWALL 5 User s Guide 142 Chapter 7 WAN Screens ...
Страница 152: ...ZyWALL 5 User s Guide 150 Chapter 8 DMZ Screens ...
Страница 174: ...ZyWALL 5 User s Guide 172 Chapter 10 Firewall Screens Figure 68 Creating Editing A Firewall Rule ...
Страница 179: ...ZyWALL 5 User s Guide Chapter 10 Firewall Screens 177 Figure 73 My Service Rule Configuration ...
Страница 220: ...ZyWALL 5 User s Guide 218 Chapter 13 Introduction to IPSec ...
Страница 238: ...ZyWALL 5 User s Guide 236 Chapter 14 VPN Screens Figure 110 VPN Rules IKE Network Policy Edit ...
Страница 261: ...ZyWALL 5 User s Guide Chapter 15 Certificates 259 Figure 122 My Certificate Details ...
Страница 280: ...ZyWALL 5 User s Guide 278 Chapter 16 Authentication Server Figure 133 Local User Database ...
Страница 317: ...ZyWALL 5 User s Guide Chapter 19 Bandwidth Management 315 ...
Страница 318: ...ZyWALL 5 User s Guide 316 Chapter 19 Bandwidth Management ...
Страница 352: ...ZyWALL 5 User s Guide 350 Chapter 21 Remote Management ...
Страница 366: ...ZyWALL 5 User s Guide 364 Chapter 23 Logs Screens Figure 188 Log Settings ...
Страница 389: ...ZyWALL 5 User s Guide Chapter 24 Maintenance 387 Figure 210 Restart Screen ...
Страница 390: ...ZyWALL 5 User s Guide 388 Chapter 24 Maintenance ...
Страница 416: ...ZyWALL 5 User s Guide 414 Chapter 27 WAN and Dial Backup Setup ...
Страница 432: ...ZyWALL 5 User s Guide 430 Chapter 30 DMZ Setup ...
Страница 492: ...ZyWALL 5 User s Guide 490 Chapter 37 System Information Diagnosis ...
Страница 508: ...ZyWALL 5 User s Guide 506 Chapter 38 Firmware and Configuration File Maintenance ...
Страница 520: ...ZyWALL 5 User s Guide 518 Chapter 40 Remote Management ...
Страница 536: ...ZyWALL 5 User s Guide 534 Chapter 42 Troubleshooting Figure 343 Java Sun ...
Страница 564: ...ZyWALL 5 User s Guide 562 Appendix C IP Subnetting ...
Страница 570: ...ZyWALL 5 User s Guide 568 Appendix E PPTP ...
Страница 571: ...ZyWALL 5 User s Guide 569 ...
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Страница 590: ...ZyWALL 5 User s Guide 588 Appendix G Triangle Route ...
Страница 620: ...ZyWALL 5 User s Guide 618 Appendix J Importing Certificates ...
Страница 622: ...ZyWALL 5 User s Guide 620 Appendix K Command Interpreter ...
Страница 628: ...ZyWALL 5 User s Guide 626 Appendix L Firewall Commands ...
Страница 632: ...ZyWALL 5 User s Guide 630 Appendix M NetBIOS Filter Commands ...
Страница 638: ...ZyWALL 5 User s Guide 636 Appendix O Brute Force Password Guessing Protection ...
Страница 660: ...ZyWALL 5 User s Guide 658 Appendix Q Log Descriptions ...