Introduction
31
Models 2211 & 2232 Getting Started Guide
3 • Wireless LAN configuration (Model 2211 only)
Introduction
IEEE 802.11, a wireless LAN standard, is the basic network element used by this device. It requires one or
more nodes and a wireless LAN access point (AP). Often, the word node refers to the notebook computers, per-
sonal computers, and PDAs that use wireless LAN cards. In this guide, node will refer to the Model device
server device server.
Infrastructure Mode and Ad-hoc Mode
An AP is most often used to connect the Model device server to the Ethernet LAN. However, it can also be
used to connect to the Internet. This type of connection is referred as an infrastructure mode. On wireless com-
puter networks, ad-hoc mode, also called peer-to-peer mode, is a method for device server devices to directly
communicate with each other without an AP. Ad-hoc mode can be very useful in replacing cables between
existing devices with a wireless connection.
Network Name: SSID (Service Set Identifier)
A wireless LAN network can be configured under different names at depending on the AP’s configuration.
SSID is an ID value that distinguishes one wireless network from another. If a network is configured in the
infrastructure mode, users need to input and set the target AP's SSID into device server so that the device
server can communicate with the target AP. Therefore, users need first to check the target AP’s SSID. On the
other hand, when using the ad-hoc mode, inter-communicating device servers should have the same SSID.
The SSID can be set to a maximum length of 32 bytes, and it can be set using ASCII characters or hexadecimal
(hex) numbers.
Channel
The device server searches for all accessible 802.11b Wireless LAN channels periodically to find other APs.
When the device server is first booted up, it searches for a preset AP (default value is Default). When the AP is
found, it accesses the AP automatically. The device server will use the channel belonging to the network group
in which it belongs. When using the infrastructure mode, the device server checks the channel values being
used in AP, and automatically sets the channel values to be identical to the AP channels values. In ad-hoc
mode, the two channels in device server should be given identical values.
Even when a certain value or an asterisk ('*') symbol is entered in a channel value entry using the
set
com-
mand, the device server will ignore those values and automatically set the values as the AP channel values of the
group in which it belongs.
Security
802.11b based applications are different from wired Ethernet applications in the way they support security
functions. The 802.11 Committee recognizes that the wired Ethernet supports a very high level of internal
security. Therefore, when creating policies for wireless LAN standards, the Committee has aimed to ensure that
Wireless has the same high level of security as that of the Ethernet.. WEP (wired equivalent privacy) uses RSA
Security’s RC4 PRNG encryption algorithm and 40-bit shared key to encrypt data. Thus, in the device server,
5 bytes of ASCII characters or 10-digit hex numbers are used to represent 64 bits of WEP1, and 13 bytes of
ASCII characters or 26-digit hex numbers are used to represent 128 bits of WEP1. The shortcoming of WEP is
that it can encrypt only the body of the data frame. Frame headers and other types of frames are not encrypted.
