NETGEAR WG302, WPN802, WG3002 Reference Manual

Reference Manual for the NETGEAR ProSafe Wireless Access Point 802.11g WG302

Glossary

Use the list below to find definitions for technical terms used in this manual.

802.11 Standard

802.11, or IEEE 802.1 1, is a type of radio technology used for wireless local area networks (WLANs). It is a
standard that has been developed by the IEEE (Institute of Electrical and Electronic Engineers),
http://standards.ieee.org. The IEEE is an international organization that develops standards for hundreds of
electronic and electrical technologies. The organization uses a series of numbers, like the Dewey Decimal
system in libraries, to differentiate between the various technology families.

The 802 subgroup (of the IEEE) develops standards for local and wide area networ ks with the 802.1 1 section
reviewing and creating standards for wireless local area networks.

Wi-Fi , 802.11, is composed of several standards operating in different radio frequencies: 802.11b is a
standard for wireless LANs operating in the 2.4 GHz spectrum with a bandwidth of 11 Mbps; 802.11a is a
different standard for wireless LANs, and pertains to systems operating in the 5 GHz frequency range with a
bandwidth of 54 Mbps. Another standard, 802.11g, is for WLANS operating in the 2.4 GHz frequency but
with a bandwidth of 54 Mbps.

802.11a Standard

An IEEE specification for wireless networking that operates in the 5 GHz frequency range (5.15 GHz to

5.85 GHz) with a maximum 54 Mbps data transfer rate. The 5 GHz frequency band is not as crowded as the

2.4 GHz frequency, because the 802.11a specification offers more radio channels than the 802.11b. These
additional channels can help avoid radio and microwave interference.

802.11b Standard

International standard for wireless networking that operates in the 2.4 GHz frequency range (2.4 GHz to

2.4835 GHz) and provides a throughput of up to 11 Mbps. This is a very commonly used frequency.
Microwave ovens, cordless phones, medical and scientific equipment, as well as Bluetooth devices, all work
within the 2.4 GHz frequency band.

802.11d Standard

802.11d is an IEEE standard supplementary to the Media Access Control (MAC) layer in 802.11 to promote
worldwide use of 802.11 WLANs. It will allow access points to communicate information on the
permissible radio channels with acceptable power levels for client devices. The devices will automatically
adjust based on geographic requirements.

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The purpose of 11d is to add features and restrictions to allow WLANs to operate within the rules of these
countries. Equipment manufacturers do not want to produce a wide variety of country-specific products and
users that travel do not want a bag full of country-specific WLAN PC cards. The outcome will be
country-specific firmware solutions.

802.11e Standard

802.11e is a proposed IEEE standard to define quality of service (QoS) mechanisms for wireless gear that
gives support to bandwidth-sensitive applications such as voice and video.

802.11g Standard

Similar to 802.11b, this physical layer standard provides a throughput of up to 54 Mbps. It also operates in
the 2.4 GHz frequency band but uses a different radio technology in order to boost overall bandwidth.

802.11i

This is the name of the IEEE Task Group dedicated to standardizing WLAN security. The 802.11i Security
has a frame work based on RSN (Robust Security Mechanism). RSN consists of two parts: 1) The Data
Privacy Mechanism and 2) Security Association Management.

The Data Privacy Mechanism supports two proposed schemes: TKIP and AES. TKIP (Temporal Key
Integrity) is a short-term solution that defines software patches to WEP to provide a minimally adequate
level of data privacy. AES or AES-OCB (Advanced Encryption Standard and Offset Codebook) is a robust
data privacy scheme and is a longer-term solution.

Security Association Management is addressed by a) RSN Negotiation Procedures, b) IEEE 802.1x
Authentication and c) IEEE 802.1x Key management.

The standards are being defined to naturally co-exist with pre-RSN networks that are currently deployed.

802.11n Standard

A recently formed (Oct 2003) IEEE official task group referred to as: 802.11n or "TGn" for the 100 Mbps
wireless physical layer standard protocol. Current published ratification date is December 2005. As of
February 2004, no draft specification has been written - It is expected to use both the 2.4 and 5GHz
frequencies.

AES (Advanced Encryption Standard)

A symmetric 128-bit block data encryption technique developed by Belgian cryptographers Joan Daemen
and Vincent Rijmen. The U.S government adopted the algorithm as its encryption technique in October
2000, replacing the DES encryption it used. AES works at multiple network layers simultaneously. The
National Institute of Standards and Technology (NIST) of the U.S. Department of Commerce selected the
algorithm, called Rijndael (pronounced Rhine Dahl or Rain Doll), out of a group of five algorithms under
consideration, including one called MARS from a large research team at IBM. AES is expected to replace
WEP as a WLAN encryption method in 2003.

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Access Point (AP)

A wireless LAN transceiver or "base station" that can connect a wired LAN to one or many wireless devices.
Access points can also bridge to each other.

There are various types of access points, also referred to as base stations, used in both wireless and wired
networks. These include bridges, hubs, switches, routers and gateways. The differences between them are
not always precise, because certain capabilities associated with one can also be added to another. For
example, a router can do bridging, and a hub may also be a switch. But they are all involved in making sure
data is transferred from one location to another.

A bridge connects devices that all use the same kind of protocol. A router can connect networks that use
differing protocols. It also reads the addresses included in the packets and routes them to the appropriate
computer station, working with any other routers in the network to choose the best path to send the packets
on. A wireless hub or access point adds a few capabilities such as roaming and provides a network
connection to a variety of clients, but it does not allocate bandwidth. A switch is a hub that has extra
intelligence: It can read the address of a packet and send it to the appropriate computer station. A wireless
gateway is an access point that provides additional capabilities such as NAT routing, DHCP, firewalls,
security, etc.

Ad-Hoc mode

A client setting that provides independent peer-to-peer connectivity in a wireless LAN. An alternative set-up
is one where PCs communicate with each other through an AP. See access point and Infrastructure mode.

Bandwidth

The amount of transmission capacity that is available on a network at any point in time. Available bandwidth
depends on several variables such as the rate of data transmission speed between networked devices,
network overhead, number of users, and the type of device used to connect PCs to a network. It is similar to
a pipeline in that capacity is determined by size: the wider the pipe, the more water can flow through it; the
more bandwidth a network provides, the more data can flow through it. Standard 802.11b provides a
bandwidth of 11 Mbps; 802.11a and 802.11g provide a bandwidth of 54 Mbps.

Bits per second (bps)

A measure of data transmission speed over communication lines based on the number of bits that can be sent
or received per second. Bits per second—bps—is often confused with bytes per second—Bps. While "bits"
is a measure of transmission speed, "bytes" is a measure of storage capability. 8 bits make a byte, so if a
wireless network is operating at a bandwidth of 11 megabits per second (11 Mbps or 11 Mbits/sec), it is
sending data at 1.375 megabytes per second (1.375 Mbps).

Bluetooth Wireless Technology

A technology specification for linking portable computers, perso nal digital assistants (PDAs) and mobile
phones for short-range transmission of voice and data across a global radio frequency band without the need

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for cables or wires. Bluetooth is a frequency-hopping technology in the 2.4 GHz frequency spectrum, with a
range of 30 feet and up to 11Mbps raw data throughput.

Bridge

A product that connects a local area network (LAN) to another local area network that uses the same
protocol (for example, wireless, Ethernet or token ring). Wireless bridges are commonly used to link
buildings in campuses.

Client or Client devices

Any computer connected to a network that requests services (files, print capability) from another member of
the network. Clients are end users. Wi-Fi client devices include PC Cards that slide into laptop computers,
mini-PCI modules embedded in laptop computers and mobile computing devices, as well as USB and PCI/
ISA bus Wi-Fi radios. Client devices usually communicate with hub devices like access points and
gateways.

Collision avoidance

A network node characteristic for proactively detecting that it can transmit a signal without risking a
collision, thereby ensuring a more reliable connection.

Crossover cable

A special cable used for networking two computers without the use of a hub. Crossover cables may also be
required for connecting a cable or DSL modem to a wireless gateway or access point. Instead of the signals
transferring in parallel paths from one set of plugs to another, the signals "crossover." If an eight-wire cable
was being used, for instance, the signal would start on pin one at one end of the cable and end up on pin
eight at the other end. They "cross-over" from one side to the other.

CSMA-CA (Carrier Sense Multiple Action)

CSMA/CA is the principle medium access method employed by IEEE 802.11 WLANs. It is a "listen before
talk": method of minimizing (but not eliminating) collisions caused by simultaneous transmission by
multiple radios. IEEE 802.11 states co llision avoidance method ra ther than collision detection must be used,
because the standard employs half duplex radios—radios capable of transmission or reception—but not both
simultaneously.

Unlike conventional wired Ethernet nodes, a WLAN station cannot detect a collision while transmitting. If a
collision occurs, the transmitting station will not receive an ACKnowledge packet from the intended receive
station. For this reason, ACK packets have a higher priority than all other network traffic. After completion
of a data transmission, the receive station will begin transmission of the ACK packet before any other node
can begin transmitting a new data packet. All other stations must wait a longer pseudo randomized period of
time before transmitting. If an ACK packet is not received, the transmitting station will wait for a subsequent
opportunity to retry transmission

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CSMA-CD (Carrier Sense Multiple Action/Collision Detection)

A method of managing traffic and reducing noise on an Ethernet network. A network device transmits data
after detecting that a channel is available. However, if two devices transmit data simultaneously , the sending
devices detect a collision and retransmit after a random time delay.

DHCP (Dynamic Host Configuration Protocol)

A utility that enables a server to dynamically assign IP addresses from a predefined list and limit their time
of use so that they can be reassigned. Without DHCP, an IT Manager would have to manually enter in all the
IP addresses of all the computers on the network. When DHCP is used, whenever a computer logs onto the
network, it automatically gets an IP address assigned to it.

Diversity: antenna

A type of antenna system that uses two antennas to maximize reception and transmission quality and reduce
interference

DNS (Domain Name System)

A program that translates URLs to IP addresses by accessing a database maintained on a collection of
Internet servers. The program works behind the scenes to facilitate surfing the Web with alpha versus
numeric addresses. A DNS server converts a name like mywebsite.com to a series of numbers like

107.22.55.26. Every website has its own specific IP address on the Internet.

Encryption Key

An alphanumeric (letters and/or numbers) series that enables data to be encrypted and then decrypted so it
can be safely shared among members of a network. WEP uses an encryption key that automatically encrypts
outgoing wireless data. On the receiving side, the same encryption key enables the computer to
automatically decrypt the information so it can be read.

Enhanced Data Encryption through TKIP

To improve data encryption, Wi-Fi Protecte d Access utilizes its Temporal Key Integrity Protocol (TKIP).
TKIP provides important data encryption enhancements including a per-packet key mixing function, a
message integrity check (MIC) named Michael, an extended initialization vector (IV) with sequencing rules,
and a re-keying mechanism. Through these enhancements, TKIP addresses all WEP known vulnerabilities.

Enterprise-level User Authentication via 802.1x and EAP

WEP has almost no user authentication mechanism. To strengthen user authentication, Wi-Fi Protected
Access implements 802.1x and the Extensible Authentication Protocol (EAP). Together, these
implementations provide a framework for strong user authentication. This framework utilizes a central
authentication server, such as RADIUS, to authenticate each user on the network before they join it, and also
employs "mutual authentication" so that the wireless user doesn’t accidentally join a rogue network that
might steal its network credentials.

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