Wireless Jargon Demystified

William Maher | Sep 12, 2008 3:44 PM

We explain port forwarding and triggering, firewalls and traffic filtering, the DMZ and other broadband bits you should know.

It shouldn’t be hard to set up port forwarding, a firewall or traffic filtering, yet the language each individual router and company uses to describe the options can be extremely perplexing.

To help clear things up, we’ve put together a list of the most confusing terms, and how to use the advanced features they refer to.

Port forwarding & triggering

What is it? Port forwarding is used to open ports in the firewall so that inbound and outbound traffic used by applications isn’t blocked or bounced. Applications employing such features include online games, instant messaging applications and P2P utilities.

Alternatives: For some reason, many routers choose not to label such features in their web-based administration pages with the simple tags Port Forwarding and Triggering. Instead, they apply all sorts of different labels.

Click through to the advanced settings on the D-Link DSL-2740B and you’ll find a section clearly labelled Port Forwarding, complete with a list of presets that allow you to define settings quickly. In other routers, such as the Netgear, they’re called Firewall Rules. Some routers refer to this capability as ALG (application layer gateway).

Where to find it: Often found in the advanced settings under Firewall, but may also be located in the NAT section.

Belkin allows easy access to guests login details from its front panel

DMZ

What is it? Where attempts to open ports fail, a demilitarised zone (DMZ) is used to open up all ports on a specified machine – usually for gaming or testing purposes. As this in effect places the PC outside the firewall and directly on the internet, it makes the machine highly vulnerable to attack. We wouldn’t recommend using a PC you rely on for work in this way.

Alternatives: DMZ can also be referred to as DMZ hosting or SMZ server.
Where to find it: This is usually located in the section that deals with the firewall.

Guest access

What is it? Guest access is used to allow visitors temporary access to the internet without allowing access to the local network. The Belkin router this month allows you to set up guest access from its front panel in what might appear to be a unique feature.

Alternatives: It isn’t as special as it looks, though. Other routers offer this feature under the term multi-SSID. The Draytek Vigor 2820n, for instance, allows up to four SSIDs to be set up, each with different security settings and access permissions. You can define one as a guest SSID, and prevent users who connect to it accessing PCs that use other SSIDs.

Where to find it: Usually in the Wireless Settings, but there may also be a separate section labelled Channel and SSID. You may even have to look in the security settings.

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In the D-Links settings, scheduling URL and website blocking facilities masquerade as parental controls

Web filtering

What is it? Used to block access to certain websites and keywords, this feature can, depending on the router, be set to block on a per-IP basis. So, some users have restricted access, while others are free to roam. Filtering can also be applied on a schedule so some websites and keywords are available only at certain times of the day.

Alternatives: These tools are also variously referred to as Parental Controls (D-Link), Block Sites (Netgear) and URL-blocking.

You may also find reference to whitelists and blacklists of sites or keywords. A whitelist blocks access to all sites apart from those on the list. So a whitelist with www.pcauthority.com.au on it will only allow access to that site.
A blacklist is the reverse of this, blocking access to URLs on the list.

Where to find it: In the firewall section of the settings, though some routers have a dedicated section called Parental Controls.

This article appeared in the October, 2008 issue of PC Authority.