This sections describes the terms a user might come across during the set-up of a wireless network.
3.1 Network Addresses
Network adapters and personal computers have to be uniquely identiﬁable in order to be accessible in a network.
Therefore each device uses a combination of the MAC address and the IP address to identify itself in a network.
3.1.1 MAC Address
The MAC (Media Access Control) address is a six byte long address which is attached to most network adapters.
This address is designed to be globally unique and is hardwired in the hardware of the network adapter. The MAC
address of a WLAN adapter can be found on a label attached to the adapter.
3.1.2 IP Address
An IP address (Internet Protocol address) is a unique number, similar in concept to a telephone number, used by
personal computers and other network devices to refer to each other when sending information through the In-
ternet. Unlike the MAC address the IP address is a software address that can be changed as often as the user likes.
An IP address is four bytes long address, usually represented as four dot separated numbers like 192.168.1.1. The
IP address of a network adapter is either set statically by the user or is provided by a DHCP server.
3.2 SSID (Service Set Identifier)
In wireless LAN networks the SSID is a label attached to every packet that is transmitted in a network. In order
to receive packets or access other computers a network adapter has to know this SSID. In other words on every
device that is connected to a dedicated wireless network, the same SSID has to be set on every device.
Since transmissions are made over a radio link in WLAN networking, the connection is susceptible to eavesdrop-
ping. Therefore two ways of authentication were foreseen in the IEEE 802.11 standards.
3.3.1 WEP (Wired Equivalent Privacy)
This way of authentication was designed to provide a way of secure communication equivalent to that of a wired
network hence the name Wired Equivalent Privacy (WEP). The encryption system uses four user-entered keys
with a length of ﬁve (or ten) characters. The ﬁve character key is used for 64bit encryption. If a safer type of en-
cryption is needed, the user can switch to 128bit encryption which uses ten character long keys. The same four
keys have to be entered on every device that wants to access the network. Unfortunately the WEP standard has
some shortcomings which make it possible to still continue eavesdropping if one has the proper equipment.
3.3.2 WPA (Wi-Fi Protected Access)
To overcome the ﬂaws of WEP, the WPA standard was created. This method uses a longer key and a protocol that
dynamically changes the key during the transmission which makes it much harder to eavesdrop on the network.
WPA is not supported by the Crystal Printer WLAN adapter.
Wireless networks use a radio link to transmit packets. Depending on the country the wireless network is set up
in, there are up to 13 channels representing speciﬁc radio frequencies. Every adapter has to use the same channel
in order to communicate in the same network.