ZyXEL Communications Corporation B122 Manuel D’Utilisation

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ZyAIR Wireless LAN Utility  
Advanced Configuration 
 
5-1 
Chapter 5 
Advanced Configuration 
This chapter shows you how to configure advanced features of the ZyAIR. 
5.1 Overview 
The following sections introduce the advanced features you can configure. 
5.1.1 Threshold Control 
Fragmentation Threshold 
Fragmentation Threshold is the maximum data fragment size (between 256 and 2432 bytes) that can be 
sent in the wireless network before the ZyAIR will fragment the packet into smaller data frames. 
A large Fragmentation Threshold is recommended for networks not prone to interference while you 
should set a smaller threshold for busy networks or networks that are prone to interference. 
If the Fragmentation Threshold value is smaller than the RTS/CTS Threshold value (see previously) 
you set 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 Threshold size. 
RTS/CTS Threshold 
A hidden node occurs when two stations are within range of the same access point, but are not within range 
of each other. The following figure illustrates a hidden node. Both stations are within range of the access 
point (AP) or 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 5-1 RTS Threshold