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Chapter 5: Configuring the Wireless-G Cable Gateway

The Wireless Tab

Wireless-G Cable Gateway

Advanced Wireless Settings Tab

On this screen you can access the Advanced Wireless features, including Basic Data Rates, Control Tx Rates,

Beacon Interval, DTIM Interval, Fragmentation Threshold, RTS Threshold, and Authentication Type.

•

Basic Data Rates. Select

Min

or

All

from the drop-down menu for rate.

•

Control Tx Rates. Select

Min

or

All

from the drop-down menu for the transmission rate. All will negotiate the

best possible connection speed between the Gateway and a wireless client.

•

Beacon Interval. The default value is

100

. Enter a value between 1 and 65,535 milliseconds. The Beacon

Interval value indicates the frequency interval of the beacon. A beacon is a packet broadcast by the Gateway

to synchronize the wireless network.

•

DTIM Interval. The default value is

3

. This value, between 1 and 255 milliseconds, indicates the interval of the

Delivery Traffic Indication Message (DTIM). A DTIM field is a countdown field informing clients of the next

window for listening to broadcast and multicast messages. When the Gateway has buffered broadcast or

multicast messages for associated clients, it sends the next DTIM with a DTIM Interval value.

Its clients hear

the beacons and awaken to receive the broadcast and multicast messages.

•

Fragmentation Threshold.

This value should remain at its default setting of

2346

. The range is 256-2346

bytes. It specifies the maximum size for a packet before data is fragmented into multiple packets. If you

experience a high packet error rate, you may slightly decrease the Fragmentation Threshold. Setting the

Fragmentation Threshold too low may result in poor network performance. Only minor modifications of this

value are recommended.

•

RTS Threshold.

This value should remain at its default setting of

2347

. The range is 0-2347 bytes. Should you

encounter inconsistent data flow, only minor modifications are recommended. If a network packet is smaller

than the preset RTS threshold size, the RTS/CTS mechanism will not be enabled. The Gateway sends Request

to Send (RTS) frames to a particular receiving station and negotiates the sending of a data frame. After

receiving an RTS, the wireless station responds with a Clear to Send (CTS) frame to acknowledge the right to

begin transmission.

•

Authentication Type. The default is set to Open System or Shared Key, which allows either Open System or

Shared Key authentication to be used. For Open System authentication, the sender and the recipient do NOT

use a WEP key for authentication. For Shared Key authentication, the sender and recipient use a WEP key for

authentication. If you want to use only Shared Key authentication, then select

Shared Key

. In most cases, you

should keep the default,

Open System or Shared Key

.

When finished making your changes on this tab, click the

Save Settings

button to save these changes, or click

the

Cancel Changes

button to undo your changes.

Figure 5-16: Advanced Wireless Settings

fragmentation:

breaking a packet into smaller units

when transmitting over a network.

dtim

(delivery traffic indication message): a message

included in data packets that can increase wireless

efficiency.

beacon internal:

data transmitted on your wireless network

that keeps the network synchronized.

packet:

a unit of data sent over a network.

rts

(request to send): a networking method of coordinating

large packets through the RTS Threshold setting.

31

Chapter 5: Configuring the Wireless-G Cable Gateway

The Wireless Tab

Wireless-G Cable Gateway

WDS Tab

Wireless Distribution System. This feature enables the Gateway to talk to a remote device within its range so it

can retransmit the signal or it can enable a wireless connection between two wired networks. The other device(s)

must support a compatible version of WDS bridging or WDS repeating.

To use this feature, click

Enable

and enter the wireless MAC address of the remote device in the

MAC

field. You

can have up to four remote devices.

When finished making your changes on this tab, click the

Save Settings

button to save these changes, or click

the

Cancel Changes

button to undo your changes.

Figure 5-17: WDS Tab

32

Chapter 5: Configuring the Wireless-G Cable Gateway

The Security Tab

Wireless-G Cable Gateway

The Security Tab

Firewall

On this screen, you can enable filters to block specific Internet data types and anonymous Internet requests.

•

Firewall Protection. Enable this feature to employ Stateful Packet Inspection (SPI) for more detailed review of

data packets entering your network environment.

•

Filter Proxy. Use of WAN proxy servers may compromise the Gateway's security. Denying Filter Proxy will

disable access to any WAN proxy servers. To enable proxy filtering, click

Enable

.

•

Filter Cookies. A cookie is data stored on your computer and used by Internet sites when you interact with

them. To enable cookie filtering, click

Enable

.

•

Filter Java Applets. Java is a programming language for websites. If you deny Java Applets, you run the risk

of not having access to Internet sites created using Java. To enable Java Applet filtering, click

Enable

.

•

Filter ActiveX. If you deny ActiveX, a programming language for websites, you run the risk of not having

access to Internet sites created using ActiveX. To enable ActiveX filtering, click

Enabled

.

•

Filter Popup Windows. When enabled, the Gateway will attempt to block the browser popup windows. Please

note that not all popups may be blocked, because of the various creation methods.

•

Filter Multicast. Multicasting allows for multiple transmissions to specific recipients at the same time. If this

multicasting is permitted, the Gateway will allow IP multicast packets to be forwarded to the appropriate

computers. Select

Enable

to filter multicasting, or

Disable

to disable this feature.

•

Block Fragmented IP Packets. Enable this feature to block any incoming or outgoing fragmented packets.

•

PortScan Alert. When enabled, the Gateway will put entries into the security log when it detects port scans

from the Internet.

•

Block WAN Requests. Enable

Block Anonymous Internet Requests

and you can prevent your network from

being “pinged,” or detected, by other Internet users. The Block WAN Request feature also reinforces your

network security by hiding your network ports. Both functions of the Block WAN Request feature make it more

difficult for outside users to work their way into your network. This feature is enabled by default. Uncheck the

box to allow anonymous Internet requests.

When finished making your changes on this tab, click the

Save Settings

button to save these changes, or click

the

Cancel Changes

button to undo your changes.

Figure 5-18: Firewall

33

Chapter 5: Configuring the Wireless-G Cable Gateway

The Security Tab

Wireless-G Cable Gateway

VPN Passthrough Tab

Virtual Private Networking (VPN) is a security measure that basically creates a secure connection between two

remote locations. The

VPN

screen allows you to configure your VPN settings to make your network more secure.

VPN Passthrough

•

IPSec Passthrough. Internet Protocol Security (IPSec) is a suite of protocols used to implement secure

exchange of packets at the IP layer. To allow IPSec Passthrough, click the

Enable

button. To disable IPSec

Passthrough, click the

Disable

button.

•

PPTP Passthrough. Point-to-Point Tunneling Protocol Passthrough is the method used to enable VPN sessions

to a Windows NT 4.0 or 2000 server. To allow PPTP Passthrough, click the

Enable

button. To disable PPTP

Passthrough, click the

Disable

button.

When finished making your changes on this tab, click the

Save Settings

button to save these changes, or click

the

Cancel Changes

button to undo your changes.

Figure 5-19: VPN

34

Chapter 5: Configuring the Wireless-G Cable Gateway

The Access Restrictions Tab

Wireless-G Cable Gateway

Figure 5-20: Website Blocking

Figure 5-21: Timed Access

The Access Restrictions Tab

The Access Restrictions tab allows you to block or allow specific kinds of Internet usage. You can set up Internet

access policies for specific computers and set up filters by using network port numbers.

Website Blocking Tab

Website/Keyword Blocking. You can filter access to various websites accessed over the Internet. Enter the

keyword or website URL in the field next to

New Website/Keyword Blocking

and click the

Add

button. The

keyword or website URL will be added to the Website/Keyword List. To unblock a website or delete a keyword,

highlight the keyword or website URL in the list and click the

Remove

button.

Timed Access Tab

Timed Access can be used to limit the days or hours of access to the network.

You can set up a Timed Access policy for each local MAC address. To use the feature, enter the MAC address in

the field, then click the

Add

button. You can also click the

Select MAC Address from Networked Computers

button.

On the new screen that appears, select a MAC address, and click the

Add

button. Click the

Refresh

button if you

want to refresh the on-screen information. Click the

Close

button to return to the previous screen.

Day to Block. Select

Everyday

, or select individual days.

Time to Block. Select

All day

or enter a specific range of hours and minutes.

When finished making your changes to a policy, click the

Save Settings

button to save these changes, or click

the

Cancel Changes

button to undo your changes.

Repeat the aforementioned steps to set up a new policy. To remove a policy, select it from the drop-down menu,

and click the

Remove

button.

Figure 5-22: MAC Address