American Academy of Family Physicians
2003 Scientific Assembly
Making Sense of Your Connectivity Options
Paul Kleeberg, M.D.
October 3rd, 2003
Revised: September 26th, 2003
Definition of Terms
For an excellent on-line encyclopedia of technology terms, see http://webopedia.internet.com/
802.11
A group of specifications developed for wireless local area networks (LAN) and allow one to create a home or office network without wires. The most popular of these are 802.11b which runs at speeds up to 11 megabits per second (Mbps) and 802.11g which runs at speeds up to 54 Mbps. Another, 802.11a also operates at 54Mbps but operates at a different frequency and its range is significantly shorter.
Bandwidth
A measure of the amount of data that can pass from one point to another. Think of it as the internal diameter of a pipe or the width of a freeway.
DHCP - Dynamic Host Configuration Protocol
Your computer is assigned a unique Internet address each time it connects. Can even change during a session.
Firewall
Serves as a filter between the WAN (wide area network or the Internet) and your machine or LAN (local area network). Firewalls can limit access to machines on the inside by IP or by port.
IP address
Abbreviation of Internet Protocol Address. A string of 4 numbers separated by periods (ex: 192.168.5.20) which function like a phone number or street address for your computer. These can either be dynamic or fixed.
NAT - Network Address Translation
Allows a local network (in a home or office) to have a range of IP addresses for internal traffic while sharing the same IP to access the Internet or WAN (Wide Area Network). These internal IP addresses would be invisible to the Internet, adding to the security of the machines on the LAN.
Ports
A logical (i.e. not physical) interface to a computer. Just like the printer connects to the parallel port or the mouse connects to the serial port (both physical) HTTP traffic connects to port 80, telnet traffic to port 23 and FTP port 21.
SSID
Service Set Identifier. The network name shared by one or more wireless access points in a single Wireless Local Area Network (WLAN).
Static IP - or Static Internet Protocol (address)
Your computer retains its unique Internet address indefinitely. Makes it easy for others to find your machine if you plan to run a web site.
WEP
Wired Equivalency Privacy. Designed to provide a wireless network with the same level of security as a wired network. Like locking your front door to your house, it will keep honest people out but a dedicated cracker would be able to get in after listening to 5 to 10 million packets. That is equivalent to about 2 weeks of evesdropping on a wireless network with 4 active users.
Paul Kleeberg, M.D. O o paul@fpen.org
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