ZyXEL 336M 91-003-192001B Benutzerhandbuch

ZyXEL P-336M User’s Guide

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Chapter 4 Advanced

This section describes advanced wireless LAN features. For more information, refer to 

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 (STA) 
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 27     RTS/CTS

When station A sends data to the Prestige, 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.

Action 

This field displays the action on the packets from the specified IP address range. 

Source IP Range

This field displays the source IP address range(s). 

Table 25   Advanced: Inbound Filter  (continued)