Tyco 0-1591700-x Authentication, Page 24 of, Wireless Access Point Model, PL0356, Issue

Wireless Access Point Model 0-1591700-x User Manual Page 24 of 33

Fragment Length

This specifies the number of bytes that are transmitted before a frame is fragmented. The longer the fragment, the more data is sent. However, where clients are working with low signal strengths when the channel bit error rate is high, then errors are likely and this will cause re-transmits to obtain error free packets. As shorter fragment lengths will be faster to re-transmit, then in marginal networks it is recommended that the fragment length be relatively short to optimise throughput. Note that setting the fragment length too short will adversely affect throughput. The available range is 256 to 2346 bytes. The default value is 2346.

RTS/CTS Threshold

Packets larger than the specified value are preceded by an RTS/CTS handshake. Enter a value between 256 and 2346 to specify the value of the RTS /CTS Threshold. The default value is 2346. If there are a large number of clients on the access point, then the number of collisions can be reduced by lowering the RTS/CTS threshold value. This threshold setting can be used to eliminate the “hidden node” problem. If the RTS/CTS Threshold is too short, then throughput will be degraded.

Hide SSID

The SSID value is broadcast by default as this simplifies installation and commissioning. However, the SSID value can be easily received and so provides a potential security problem. For higher security networks, it is recommended that the Hide SSID checkbox is set. The default is Off.

Authentication

Authentication Type

This setting is used as part of the Wired Equivalent Privacy (WEP) encryption. There are two Authentication modes and if WEP is required then one of these modes must be selected. The options are Open System and Shared Key. All stations on the network must use the same authentication type. If you don't want to use WEP Encryption, select NONE to disable this function.

•Open System allows any client to authenticate against WEP as long as the client is accepted by the MAC address filtering rules (see page 21). All authentication packets are passed un- encrypted. This is the weakest level of security.

•Shared Key is used when both the sender and receiver share a secret key. In this mode, the access point sends an un-encrypted challenge text string to the requesting client. The requesting client then encrypts the challenge text and sends it back to the access point. If the encrypted text is correctly received then the access point permits the requesting client to authenticate.

WEP Encryption

WEP is designed to provide a similar level of basic security as that of a wired LAN. However, WEP is not a strong encryption system and should be used with care and always alongside other security measures. The access point offers three WEP encryption key lengths: 64-bit (10 hex digits), 128 bit (26 hex digits) and 152 bit (32 hex digits). When a key length is selected, then a sub-menu is displayed. The WEP mode encrypts each frame transmitted from the radio using the selected key set. There are 4 key sets can be entered and only one set is active at any time. Only hexadecimal values (0 to 9 and A to F) are accepted as key values. If other character values are entered, then an error message is displayed. Key entry can be simplified by entering the keys into a simple text editor and saving the file. Then copy and paste the key(s) into the required fields. The default value of WEP Encryption is None.

PL0356 ©2003TycoElectronics Issue 1