Network Adapter:

A network adapter is a device expansion card that provides the physical connection between a computer and the network.

There are many types of adapters. They include PC cards for laptops, a card that fits into a slot on your computer, just like you

install a sound card or modem card, and embedded cards, embedded USB adapters, USB dongle adapters, and USB desktop

adapters. Some newer computers have a network adapter already built into the system. PC cards or cards that fit into a slot in

the desktop are sometimes referred to as network interface cards, or NICs.

Network Address Translation (NAT):

NAT occurs when multiple

IP addresses

on a private

LAN

are converted to one public address. This public address is sent out

to the Internet. NAT adds a level of security because the IP address for a PC connected to the private LAN is never

transmitted to the Internet. NAT also allows xDSL/cable routers to be used with low-cost Internet accounts, where only one

TCP/IP

address is provided by the

Internet service provider.

The user may have many private addresses masked by the single

address provided by the ISP. NAT prevents denial of service (DoS) from external networks on internal hosts.

Network Name (SSID):

Access points

are grouped together by an identifier called an ESSID. The ESSID is also referred to as a Net ID. This identifier

is a combination of any letters or numbers that are appropriate for the network environment. ESSID is specifically for access

points. When you talk about peer-to-peer networks, you cannot use the term ESSID.

Service Set Identifier (SSID) is more generic and is a 32-character name that uniquely identifies all the computers and

equipments that make up a wireless network. A type of SSID is ESSID. Another type of SSID is Basic Service Set Identifier

(BSSID). The BSSID is the

MAC address

of a wireless

adapter

or access point.

Point to Point Protocol over Ethernet (PPPoE):

PPPoE is the methodology of authenticating or validating a user or equipment to an

Internet service provider,

usually via a

username and/or password. It is a selection or action that reconfigures a device to the default parameters, as it was originally

manufactured.

Port:

A port is a connector on a networking device, used to attach the network cable. Hubs and switches have numerous ports that

connect to computers on the network.

Protocol:

Protocol refers to a set of rules for sending and receiving information on a network. The rules determine the format of the data

that is transmitted and other aspects of networking, such as how errors are detected and corrected. The protocol driver in each

computer is software that adheres to these rules when sending and receiving information. These drivers are also often called

protocols.

Transmission Control Protocol/Internet Protocol (TCP/IP):

TCP/IP refers to the

protocol

that computers use to communicate over the Internet. TCP determines how a computer breaks up

data into small units, called "packets," to be sent to another computer and how the receiving computer reassembles the

packets into a single file. IP determines how the packets are routed across the Internet.

See Internet Protocol.

Virtual Local Area Network (VLAN):

A VLAN is a network of computers that behave as if they are connected to the same wire, even though they may be physically

located on different segments of a LAN. VLANs are configured through software rather than hardware, which makes them

extremely flexible. When a computer on a VLAN is physically moved to another location, it can stay on the same VLAN without

any hardware reconfigurations.

Virtual Server:

A virtual server is a device that performs Internet protocol (IP) mapping. IP mapping allows remote client access to your

network via the Internet.

Wide Area Network (WAN):

A WAN is a communications network that uses devices such as telephone lines, satellite dishes, or radio waves to span a

larger geographic area than can be covered by a

LAN.

Wireless Local Area Network (WLAN):

A WLAN is a type of

Local Area Network (LAN)

that uses high frequency radio waves rather than wires to communicate and

transmit data among the network clients and devices. It is a flexible data communication system implemented as an extension

to, or as an alternative for, a wired LAN. Just like a LAN, the network lets users at that location share files, printers and other

services.

xDSL Modem:

DSL is a type of service that allows people to access the Internet via their telephone lines. This service is typically available via

a telephone company or service provider.

An xDSL connection is a high-speed digital connection to the Internet using standard copper twisted pair telephone wires.

There are several kinds of DSL; the x refers to all of them.

Dell™TrueMobile™2300 Wireless Broadband Router

User's Guide

Contents

Introduction

Managing Your Router

Configuration Steps for Common Scenarios

Technical Specifications and Regulatory Information

FAQs

Glossary

Online Customer Support

Information in this document is subject to change without notice.

© 2003 Dell Computer Corporation. All rights reserved.

Trademarks used in this text:

Dell,

the

DELL

logo, and

TrueMobile

are trademarks of Dell Computer Corporation;

Microsoft

and

Windows

are registered trademarks of Microsoft Corporation. Other trademarks and trade names may be used in this document

to refer to either the entities claiming the marks and names or their products. Dell disclaims any proprietary interest in

trademarks and trade names other than its own.

P/N M1683 Revision A00, July 2003

Back to Contents Page

Wireless Networking Overview:

Dell™ TrueMobile™ 2300 Wireless Broadband Router User's

Guide

Wireless Local Area Network (WLAN)

Identifying a WLAN

Encryption

Automatic Rate Selection and Rate Scaling

Wireless Local Area Network (WLAN)

A

Local Area Network

(LAN) is a network in one location. Users at that location can share files, printers, and other services. In

a LAN, a networked computer that requests services is called a client. A

Wireless Local Area Network

(WLAN) is a type of LAN

that uses high frequency radio waves rather than wires to communicate and transmit data among the network clients and

devices. It is a flexible data communication system implemented as an extension to, or as an alternative for, a wired LAN.

In a WLAN, wireless adapters are installed in clients, also called wireless clients. The adapter allows the wireless client to

communicate with the WLAN without cables. Instead, wireless clients send and receive information through a path in the air

called a channel.

The standards for a WLAN are based on the IEEE 802.11b standard and proposed 802.11g standard. All Dell 802.11b/g-

compliant devices interoperate with other 802.11b/g -compliant wireless devices from other vendors. The WiFi certification logo

indicates that the wireless device has been tested by an independent organization.

A wireless client operates in either infrastructure mode or peer-to-peer mode.

Back to Top

Identifying a WLAN

An ESSID and BSSID are both

Service Set Identifiers

(SSID) that identify and control the wireless client’s access to a given

WLAN. The SSID is sometimes referred to as the network name. The SSID indicates what WLAN you are referring to. In most

cases, the user interface displays the SSID.

When installing an access point or wireless adapter in a wireless client, the installation program asks you to enter the SSID.

Dell cannot provide you with this information, as it is specific to your network; although, you may choose to use the default

SSID, "wireless", for your Wireless Broadband Router. All wireless clients and access points in a WLAN must use the same

network name.

Back to Top

Encryption

In a WLAN, wireless clients and access points send and receive information through the air. Without implementing security, it is

possible for an unauthorized person to intercept the information.

A common way of implementing security and protecting information is

encryption

. Encryption applies a set of instructions, called

an

algorithm

, to information. The instructions combine the

plain

or

clear

text of information with a sequence of hexadecimal

numbers, called an

encryption key

.

Before transmitting information over the airwaves, the wireless client or access point

encrypts

or scrambles the information.

The access point or wireless client receiving the information uses the same key to

decrypt

or unscramble the information. The

information is only readable to WLAN devices that have the correct encryption key. The longer the key is, the stronger the

encryption.

TrueMobile 2300 supports both WEP (Wired Equivalent Privacy) and WPA (Wi-Fi Protected Access).

WEP

WEP provides a way of creating an encrypted key that is shared between a wireless client (such as a notebook with a wireless

PC card) and the router. In Wireless Broadband Router, WEP is an optional feature that can be enabled or disabled. When

WEP encryption is enabled, you must set the WEP key in the client to match the WEP key used by the access point because

you can ONLY connect to access points that have a matching WEP Key.

Note: It is better to change keys frequently. The same algorithm is used for all the communications that should be

protected. If the same key is used, the same message will give exactly the same cipher text. Then, it will be possible

for an eavesdropper to break the encrypted data. For this reason, it is strongly recommended to change keys often.

There are two WEP encryption methods:

40(64)-bit Encryption

104(128)-bit Encryption

40-bit and 64-bit encryption are identical. Some vendors use the term 40-bit; others use 64-bit. A wireless device that claims to

have 40-bit encryption interoperates with a device that claims to have 64-bit encryption, and vice versa. A 40(64)-bit key

consists of 10 hexadecimal numbers, arrayed as follows:

Key #1: 1011121314

Key #2: 2021222324

Key #3: 3031323334

Key #4: 4041424344

A 104(128)-bit key has several trillion times as many possible combinations than a 40(64)-bit key. It consists of 26 hexadecimal

numbers, arrayed as follows:

Key (#1): 101112131415161718191A1B1C

All wireless clients and access points in a WLAN must use the same encryption method and key. The following two examples

stress how important this point is.

Example 1

The encryption method for an access point is 40(64)-bit. The method for a wireless client is 104(128)-bit encryption. The client

and access point cannot communicate with each other, even though the selected key is the same. To resolve this problem, set

the access point to use 104(128)-bit encryption.

Example 2

The encryption method is the same for the access point and wireless client. You select key 1 for the access point and key 2

for the wireless client. The wireless client cannot communicate with the WLAN. To resolve this problem, select key 1 for the

wireless client.

CAUTION: Use the same key and encryption method for the wireless devices in the WLAN. Otherwise, they

cannot communicate with each other.

The Wireless Broadband Router uses either hexadecimal digits or ASCII characters to create encryption keys. Hexadecimal

digits include the numbers 0 to 9 and the letters A to F. For example, the decimal number 15 is represented as F in the

hexadecimal numbering system.