Wireless Glossary

LAN – A Local Area Network is a computer that spans a small area. LANs are
usually confined to a single building or group of buildings. However, one LAN can be
connected to other LANs over any distance via fiber optics, telephone lines, radio waves
etc. A system of LANs connected in this way is called a wide-area network (WAN).

NIH Firewall – Since NIH provides NCI-Frederick’s link to the internet they also provide some
protection via a firewall. A firewall is a filter allowing some and denying most network traffic
based on its origin, destination, type, and ports in use.

VPN – Virtual Private Networking is a means of using an internet or intranet connection to gain
secure access to a Network. It uses a single network connection to tunnel traffic through avoiding
firewall issues that occur outside the network and to provide a secure connection from any location
inside or outside your secured network. There are different forms of VPN but most use a client and
a server located on the border of your network.

WiFi – Wireless Fidelity is a term used for a device that has met the IEEE standards required for basic
802.11 networking. It is not a guarantee your device is compatible with all WiFi networks but instead
it is a sign of its compatibility at the time of manufacture.

VLAN – A Virtual Local Area Network is a switched segment of a network used to separate broadcast
traffic from the rest of the network and to group machines and users in order to provide custom abilities
without creating them network wide as in a hub based network.

WLAN – Wireless Local Area Networks are simply LANs configured to primarily use wireless as
form of connection. In a LAN the user would be wired to the network and with WLAN the connections are
wireless.

LEAP – Lightweight Extensible Authentication Protocol is a Cisco proprietary method of authenticating
to a RADIUS server derived from and still compatible with IEEE WPA pre-standards.

RADIUS – Remote Access Dial -In User Service is a server based program used to authenticate users on
a network via username and password. Implementation requires that the destination and origin equipment
be RADIUS aware.

WEP – Wireless Encryption Protocol is a method of keying network data with a cipher to be deciphered
once the data packet reaches its destination. There are two standard types of WEP keys. One form is a
40 bit key standard and the more recent is a stronger 128 bit key. Some systems auto-assign these keys and
rotate them and some must be entered manually.

802.11 – 802.11 is the technical term for the protocol used in wireless networks much like the 10BaseT was
to Ethernet. There are several versions of the protocol some of which are intended for LANs and some for
WLANs. 802.11b access points only work with 802.11b card although 802.11g is backward compatible
with 802.11b. 802.11b operates at 11Mbs speeds and 802.11g at 54Mbs speeds and all of these three use
the 2.4-2.5GHz frequency. 802.11a uses the 5GHz

Access Point – The term Access point refers to the network device that is connected to the network allowing
the wireless clients to access the network via radio waves. They are sometimes referred to as radios. These
radios can be connected to the network via wired or wireless bridge.

WPA – WiFi Protected Access is the first standard since WEP and was designed to eliminate the inherent
security weaknesses with static WEP. At the time this glossary was compiled WPA2 standards were in the
ratification stage. WPA offers both local and infrastructure configurations missing from earlier security types.

SSID - Service Set Identifiers (SSID) is a unique identifier attached to the header of packets sent over a wireless LAN. It is primarily intended to differentiate LANs, but also acts as a rudimentary password. You will also need to enter a SSID into your wireless client to enable you to access NIH wireless resources. The SSID for the NIH campus can be obtained from the IT person responsible for your area or by contacting the NIH Help Desk.