Chapter 11 Wireless LAN

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76

11.1.1

What You Can Do in this Chapter

•

Use the

General

screen to enable or disable wireless LAN, configure SSID, operating channel,

and wireless security (

Section 11.2 on page 79

).

•

Use the

MAC Filter

screen to allow or deny wireless stations based on their MAC addresses from

connecting to the NBG5715 (

Section 11.4 on page 85

).

•

Use the

Advanced

screen to allow intra-BSS networking and set the RTS/CTS Threshold (

Section

11.5 on page 86

).

•

Use the

QoS

screen to ensure Quality of Service (QoS) in your wireless network (

Section 11.6 on

page 87

).

•

Use the

WPS

screen to quickly set up a wireless network with strong security, without having to

configure security settings manually (

Section 11.7 on page 87

).

•

Use the

WPS Station

screen to add a wireless station using WPS (

Section 11.8 on page 89

).

•

Use the

Scheduling

screen to set the times your wireless LAN is turned on and off (

Section 11.9

on page 89

).

11.1.2

What You Should Know

Every wireless network must follow these basic guidelines.

•

Every wireless client in the same wireless network must use the same SSID.

The SSID is the name of the wireless network. It stands for Service Set IDentity.

•

If two wireless networks overlap, they should use different channels.

Like radio stations or television channels, each wireless network uses a specific channel, or

frequency, to send and receive information.

•

Every wireless client in the same wireless network must use security compatible with the AP.

Security stops unauthorized devices from using the wireless network. It can also protect the

information that is sent in the wireless network.

Wireless Security Overview

The following sections introduce different types of wireless security you can set up in the wireless

network.

SSID

Normally, the AP acts like a beacon and regularly broadcasts the SSID in the area. You can hide the

SSID instead, in which case the AP does not broadcast the SSID. In addition, you should change

the default SSID to something that is difficult to guess.

This type of security is fairly weak, however, because there are ways for unauthorized devices to

get the SSID. In addition, unauthorized devices can still see the information that is sent in the

wireless network.

MAC Address Filter

Every wireless client has a unique identification number, called a MAC address.

1

A MAC address is

usually written using twelve hexadecimal characters

2

; for example, 00A0C5000002 or

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00:A0:C5:00:00:02. To get the MAC address for each wireless client, see the appropriate User’s

Guide or other documentation.

You can use the MAC address filter to tell the AP which wireless clients are allowed or not allowed to

use the wireless network. If a wireless client is allowed to use the wireless network, it still has to

have the correct settings (SSID, channel, and security). If a wireless client is not allowed to use the

wireless network, it does not matter if it has the correct settings.

This type of security does not protect the information that is sent in the wireless network.

Furthermore, there are ways for unauthorized devices to get the MAC address of an authorized

wireless client. Then, they can use that MAC address to use the wireless network.

User Authentication

You can make every user log in to the wireless network before they can use it. This is called user

authentication. However, every wireless client in the wireless network has to support IEEE 802.1x

to do this.

For wireless networks, there are two typical places to store the user names and passwords for each

user.

•

In the AP: this feature is called a local user database or a local database.

•

In a RADIUS server: this is a server used in businesses more than in homes.

If your AP does not provide a local user database and if you do not have a RADIUS server, you

cannot set up user names and passwords for your users.

Unauthorized devices can still see the information that is sent in the wireless network, even if they

cannot use the wireless network. Furthermore, there are ways for unauthorized wireless users to

get a valid user name and password. Then, they can use that user name and password to use the

wireless network.

Local user databases also have an additional limitation that is explained in the next section.

Encryption

Wireless networks can use encryption to protect the information that is sent in the wireless

network. Encryption is like a secret code. If you do not know the secret code, you cannot

understand the message.

1.

Some wireless devices, such as scanners, can detect wireless networks but cannot use wireless networks. These kinds

of wireless devices might not have MAC addresses.

2.

Hexadecimal characters are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, and F.

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The types of encryption you can choose depend on the type of user authentication. (See

page 77

for information about this.)

For example, if the wireless network has a RADIUS server, you can choose

WPA

or

WPA2

. If users

do not log in to the wireless network, you can choose no encryption,

Static WEP

,

WPA-PSK

, or

WPA2-PSK

.

Usually, you should set up the strongest encryption that every wireless client in the wireless

network supports. For example, suppose the AP does not have a local user database, and you do

not have a RADIUS server. Therefore, there is no user authentication. Suppose the wireless network

has two wireless clients. Device A only supports WEP, and device B supports WEP and WPA.

Therefore, you should set up

Static WEP

in the wireless network.

Note: It is recommended that wireless networks use

WPA-PSK

,

WPA

, or stronger

encryption. IEEE 802.1x and WEP encryption are better than none at all, but it is

still possible for unauthorized devices to figure out the original information pretty

quickly.

Note: It is not possible to use

WPA-PSK

,

WPA

or stronger encryption with a local user

database. In this case, it is better to set up stronger encryption with no

authentication than to set up weaker encryption with the local user database.

When you select

WPA2

or

WPA2-PSK

in your NBG5715, you can also select an option (

WPA

Compatible

) to support WPA as well. In this case, if some wireless clients support WPA and some

support WPA2, you should set up

WPA2-PSK

or

WPA2

(depending on the type of wireless network

login) and select the

WPA Compatible

option in the NBG5715.

Many types of encryption use a key to protect the information in the wireless network. The longer

the key, the stronger the encryption. Every wireless client in the wireless network must have the

same key.

WPS

WiFi Protected Setup (WPS) is an industry standard specification, defined by the WiFi Alliance. WPS

allows you to quickly set up a wireless network with strong security, without having to configure

security settings manually. Depending on the devices in your network, you can either press a

button (on the device itself, or in its configuration utility) or enter a PIN (Personal Identification

Number) in the devices. Then, they connect and set up a secure network by themselves. See how

to set up a secure wireless network using WPS in the

Section 9.2 on page 57

.

WDS

Wireless Distribution System or WDS security is used between bridged APs. It is independent of the

security between the wired networks and their respective APs. If you do not enable WDS security,

Table 27

Types of Encryption for Each Type of Authentication

NO AUTHENTICATION

RADIUS SERVER

Weakest

No Security

WPA

Static WEP

WPA-PSK

Strongest

WPA2-PSK

WPA2

Chapter 11 Wireless LAN

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79

traffic between APs is not encrypted. When WDS security is enabled, both APs must use the same

pre-shared key.

11.2

The General Wireless LAN Screen

Use this screen to configure the SSIDs of the wireless LAN.

Note: If you are configuring the NBG5715 from a computer connected to the wireless LAN

and you change the NBG5715’s SSID, channel or security settings, you will lose

your wireless connection when you press

Apply

to confirm. You must then change

the wireless settings of your computer to match the NBG5715’s new settings.

Click

Network

>

Wireless LAN 2.4G/5G

to open the

General

screen.

Figure 43

Network > Wireless LAN 2.4G/5G > General

The following table describes the general wireless LAN labels in this screen.

Table 28

Network > Wireless LAN 2.4G/5G > General

LABEL

DESCRIPTION

Wireless LAN

Select

Enable

to activate the 2.4G and/or 5G wireless LAN. Select

Disable

to turn

it off.

Name(SSID)

The SSID (Service Set IDentity) identifies the Service Set with which a wireless

client is associated. Enter a descriptive name (up to 32 printable characters found

on a typical English language keyboard) for the wireless LAN.

Hide SSID

Select this check box to hide the SSID in the outgoing beacon frame so a station

cannot obtain the SSID through scanning using a site survey tool.

Channel

Selection

Set the operating frequency/channel depending on your particular region.

Select a channel from the drop-down list box. The options vary depending on the

frequency band and the country you are in.

This option is only available if

Auto Channel Selection

is disabled.

Auto Channel

Selection

Select this check box for the NBG5715 to automatically choose the channel with

the least interference. Deselect this check box if you wish to manually select the

channel using the

Channel Section

field.

Chapter 11 Wireless LAN

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See the rest of this chapter for information on the other labels in this screen.

Operating

Channel

This displays the channel the NBG5715 is currently using.

Channel Width

Select the wireless channel width used by NBG5715.

A standard

MHz channel offers transfer speeds of up to 216.7 Mbps whereas a

40MHz channel uses two standard channels and offers speeds of up to 450 Mbps.

Because not all devices support 40 MHz channels, select

Auto /40MHz

to allow

the NBG5715 to adjust the channel bandwidth automatically.

Select

MHz

to lessen radio interference with other wireless devices in your

neighborhood.

Wireless Mode

If you are in the

Wireless LAN 2.4G > General

screen, you can select from the

following:

•

802.11b

: allows either IEEE 802.11b or IEEE 802.11g compliant WLAN devices

to associate with the NBG5715. In this mode, all wireless devices can only

transmit at the data rates supported by IEEE 802.11b.

•

802.11g

: allows IEEE 802.11g compliant WLAN devices to associate with the

Device. IEEE 802.11b compliant WLAN devices can associate with the NBG5715

only when they use the short preamble type.

•

802.11bg

: allows either IEEE 802.11b or IEEE 802.11g compliant WLAN

devices to associate with the NBG5715. The NBG5715 adjusts the transmission

rate automatically according to the wireless standard supported by the wireless

devices.

•

802.11n

: allows IEEE 802.11n compliant WLAN devices to associate with the

NBG5715. This can increase transmission rates, although IEEE 802.11b or IEEE

802.11g clients will not be able to connect to the NBG5715. I

•

802.11gn

: allows either IEEE 802.11g or IEEE 802.11n compliant WLAN

devices to associate with the

NBG5715. The transmission rate of your

NBG5715 might be reduced.

•

802.11 bgn

: allows IEEE802.11b, IEEE802.11g and IEEE802.11n compliant

WLAN devices to associate with the NBG5715. The transmission rate of your

NBG5715 might be reduced.

If you are in the

Wireless LAN 5G > General

screen, you can select from the

following:

•

802.11a

: allows only IEEE 802.11a compliant WLAN devices to associate with

the NBG5715.

•

802.11an

: allows both IEEE802.11n and IEEE802.11a compliant WLAN devices

to associate with the NBG5715. The transmission rate of your NBG5715 might

be reduced.

Security Mode

Select

Static WEP

,

WPA-PSK

,

WPA

,

WPA2-PSK

or

WPA2

to add security on this

wireless network. The wireless clients which want to associate to this network must

have same wireless security settings as this device. After you select to use a

security, additional options appears in this screen. See

Section 11.3 on page 81

for

detailed information on different security modes. Or you can select No Security to

allow any client to associate this network without authentication.

Note: If the WPS function is enabled (default), only

No Security

,

WPA-PSK

and

WPA2-PSK

are available in this field.

Apply

Click

Apply

to save your changes back to the NBG5715.

Cancel

Click

Cancel

to reload the previous configuration for this screen.

Table 28

Network > Wireless LAN 2.4G/5G > General (continued)

LABEL

DESCRIPTION