NETGEAR WG302 - 802.11g ProSafe Wireless Access... User manual

Reference Manual for the NETGEAR ProSafe Wireless Access Point 802.11g WG302
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Glossary
Use the list below to find definitions for technical terms used in this manual.
802.11 Standard
802.11, or IEEE 802.11, 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 networks with the 802.11 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, personal 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 collision avoidance method rather 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 Protected 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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ESSID (more commonly referred to as SSID – Short Set Identifier)
The identifying name of an 802.11 wireless network. When you specify your correct ESSID in your client
setup you ensure that you connect to your wireless network rather than another network in range. (See
SSID.) The ESSID can be called by different terms, such as Network Name, Preferred Network, SSID or
Wireless LAN Service Area.
Ethernet
International standard networking technology for wired implementations. Basic 10BaseT networks offer a
bandwidth of about 10 Mbps. Fast Ethernet (100 Mbps) and Gigabit Ethernet (1000 Mbps) are becoming
popular.
Firewall
A system that secures a network and prevents access by unauthorized users. Firewalls can be software,
hardware or a combination of both. Firewalls can prevent unrestricted access into a network, as well as
restrict data from flowing out of a network.
Gateway
In the wireless world, a gateway is an access point with additional software capabilities such as providing
NAT and DHCP. Gateways may also provide VPN support, roaming, firewalls, various levels of security,
etc.
Hot Spot (also referred to as Public Access Location)
A place where you can access Wi-Fi service. This can be for free or for a fee. HotSpots can be inside a coffee
shop, airport lounge, train station, convention center, hotel or any other public meeting area. Corporations
and campuses are also implementing HotSpots to provide wireless Internet access to their visitors and
guests. In some parts of the world, HotSpots are known as CoolSpots.
Hub
A multiport device used to connect PCs to a network via Ethernet cabling or via Wi-Fi. Wired hubs can have
numerous ports and can transmit data at speeds ranging from 10 Mbps to multigigabyte speeds per second.
A hub transmits packets it receives to all the connected ports. A small wired hub may only connect 4
computers; a large hub can connect 48 or more. Wireless hubs can connect hundreds.
HZ (‘hertz”)
The international unit for measuring frequency, equivalent to the older unit of cycles per second. One
megahertz (MHz) is one million hertz. One gigahertz (GHz) is one billion hertz. The standard US electrical
power frequency is 60 Hz, the AM broadcast radio frequency band is 535—1605 kHz, the FM broadcast
radio frequency band is 88—108 MHz, and wireless 802.11b LANs operate at 2.4 GHz.

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IEEE (Institute of Electrical and Electronics Engineers)
A membership organization (www.ieee.org) that includes engineers, scientists and students in electronics
and allied fields. It has more than 300,000 members and is involved with setting standards for computers and
communications.
IEEE 802.11
A set of specifications for LANs from The Institute of Electrical and Electronics Engineers (IEEE). Most
wired networks conform to 802.3, the specification for CSMA/CD based Ethernet networks or 802.5, the
specification for token ring networks. 802.11 defines the standard for wireless LANs encompassing three
incompatible (non-interoperable) technologies: Frequency Hopping Spread Spectrum (FHSS), Direct
Sequence Spread Spectrum (DSSS) and Infrared. WECA’s (Wireless Ethernet Compatibility Alliance – now
Wi-Fi Alliance) focus is on 802.11b, an 11 Mbps high-rate DSSS standard for wireless networks.
Infrastructure mode
A client setting providing connectivity to an access point (AP). As compared to Ad-Hoc mode, whereby PCs
communicate directly with each other, clients set in Infrastructure Mode all pass data through a central AP.
The AP not only mediates wireless network traffic in the immediate neighborhood, but also provides
communication with the wired network. See Ad-Hoc and AP.
IP (Internet Protocol) address
A 32-bit number that identifies each sender or receiver of information that is sent across the Internet. An IP
address has two parts: an identifier of a particular network on the Internet and an identifier of the particular
device (which can be a server or a workstation) within that network.
ISO Network Model
A network model developed by the International Standards Organization (ISO) that consists of seven
different levels, or layers. By standardizing these layers, and the interfaces in between, different portions of
a given protocol can be modified or changed as technologies advance or systems requirements are altered.
The seven layers are:
• Physical
• Data Link
•Network
• Transport
• Session
• Presentation
• Application
The IEEE 802.11 Standard encompasses the physical layer (PHY) and the lower portion of the data link
layer. The lower portion of the data link layer is often referred to as the Medium Access Controller (MAC)
sublayer.

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MAC (Media Access Control)
Every wireless 802.11 device has its own specific MAC address hard-coded into it. This unique identifier
can be used to provide security for wireless networks. When a network uses a MAC table, only the 802.11
radios that have had their MAC addresses added to that network's MAC table will be able to get onto the
network.
Mesh Networks
Also called mesh topology, mesh is a network topology in which devices are connected with many
redundant interconnections between network nodes. In a full mesh topology every node has a connection to
every other node in the network. Mesh networks may be wired or wireless.
In a wireless mesh example, each of the spheres below represent a mesh router. Corporate servers and
printers may be shared by attaching to each mesh router. For wireless access to the mesh, an access point
must be attached to any one of the mesh routers.
Multiple Input Multiple Output (MIMO)
MIMO refers to radio links with multiple antennas at the transmitter and the receiver side to improve the
performance of the wireless link.
NAT (Network Address Translation)
A network capability that enables a houseful of computers to dynamically share a single incoming IP
address from a dial-up, cable or xDSL connection. NAT takes the single incoming IP address and creates
new IP address for each client computer on the network.
Network name
Identifies the wireless network for all the shared components. During the installation process for most
wireless networks, you need to enter the network name or SSID. Different network names are used when
setting up your individual computer, wired network or workgroup.

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NIC (Network Interface Card)
A type of PC adapter card that either works without wires (Wi-Fi) or attaches to a network cable to provide
two-way communication between the computer and network devices such as a hub or switch. Most office
wired NICs operate at 10 Mbps (Ethernet), 100 Mbps (Fast Ethernet) or 10/100 Mbps dual speed.
High-speed Gigabit and 10 Gigabit NIC cards are also available. See PC Card.
PC card (also called PCMCIA)
A removable, credit-card-sized memory or I/O (input/output) device that fits into a Type 2 PCMCIA
standard slot, PC Cards are used primarily in PCs, portable computers, PDAs and laptops. PC Card
peripherals include Wi-Fi cards, memory cards, modems, NICs, hard drives, etc.
PCI adapter
A high-performance I/O computer bus used internally on most computers. Other bus types include ISA and
AGP. PCIs and other computer buses enable the addition of internal cards that provide services and features
not supported by the motherboard or other connectors.
Peer-to-peer network (also called Ad-Hoc in WLANs)
A wireless or wired computer network that has no server or central hub or router. All the networked PCs are
equally able to act as a network server or client, and each client computer can talk to all the other wireless
computers without having to go through an access point or hub. However, since there is no central base
station to monitor traffic or provide Internet access, the various signals can collide with each other, reducing
overall performance.
PHY
The lowest layer within the OSI Network Model. It deals primarily with transmission of the raw bit stream
over the PHYsical transport medium. In the case of wireless LANs, the transport medium is free space. The
PHY defines parameters such as data rates, modulation method, signaling parameters, transmitter/receiver
synchronization, etc. Within an actual radio implementation, the PHY corresponds to the radio front end and
baseband signal processing sections.
Plug and Play
A computer system feature that provides for automatic configuration of add-ons and peripheral devices such
as wireless PC Cards, printers, scanners and multimedia devices.
Proxy server
Used in larger companies and organizations to improve network operations and security, a proxy server is
able to prevent direct communication between two or more networks. The proxy server forwards allowable
data requests to remote servers and/or responds to data requests directly from stored remote server data

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Range
The distance away from your access point that your wireless network can reach. Most Wi-Fi systems will
provide a range of a hundred feet or more. Depending on the environment and the type of antenna used,
Wi-Fi signals can have a range of up to mile
Residential gateway
A wireless device that connects multiple PCs, peripherals and the Internet on a home network. Most Wi-Fi
residential gateways provide DHCP and NAT as well.
RJ-45
Standard connectors used in Ethernet networks. Even though they look very similar to standard RJ-11
telephone connectors, RJ-45 connectors can have up to eight wires, whereas telephone connectors have only
four.
Roaming
Moving seamlessly from one AP coverage area to another with your laptop or desktop with no loss in
connectivity.
Rogue Access Point
"Rogue AP" is a term used to describe an unauthorized access point that is connected on the main home or
corporate network or operating in a stand-alone mode (in a parking lot or in a neighbor's building). Rogue
APs, by definition, are not under the management of network administrators and do not conform to network
security policies and may present a severe security risk. Ideally, it is best to have some type of WLAN
system that does not allow rogue access points to easily be added to an existing WLAN.
Router
A device that forwards data packets from one local area network (LAN) or wide area network (WAN) to
another. Based on routing tables and routing protocols, routers can read the network address in each
transmitted frame and make a decision on how to send it via the most efficient route based on traffic load,
line costs, speed, bad connections, etc.
Satellite broadband
A wireless high-speed Internet connection provided by satellites. Some satellite broadband connections are
two-way—up and down. Others are one-way, with the satellite providing a high-speed downlink and then
using a dial-up telephone connection or other land-based system for the uplink to the Internet.
Server
A computer that provides its resources to other computers and devices on a network. These include print
servers, Internet servers and data servers. A server can also be combined with a hub or router.