2. Product Types - Access Points (AP) and Bridges

Access Points

In its generic form, an Access Point is a wireless transceiver that connects a wired LAN with wireless clients. An AP makes this connection in a way that makes the wired and wireless clients appear to be in the same network.

NOTE: An AP in its basic form can only connect to wireless clients, and not to another AP.

This category of devices can get confusing, given the way that some manufacturers have named their products and enhanced their feature sets to include "bridging" features. See the next section for more info.

Bridges

The generic networking term "Bridge" refers to a device that connects two LANs. Therefore, when you want to connect two (or more) LANs via a wireless connection, use wireless bridges.

But beware! This product category is probably the most confusing, and holds the most potential for a customer to choose a product that doesn't really do what they require. For example, a number of manufacturers have added bridging features to their Access Points and not renamed their products (Linksys WAP11, Netgear ME102), or called their products bridges when they also support Access Point functions (SMC 2682W). There are also "bridge" products that support only one attached device. Our only advice here is to read the product feature description very carefully and don't rely on the name of a product to tell you what it does.

Once you select a product, you'll have to configure it. There are a number of wireless bridging modes, and of course, manufacturers have not used the same terminology. Let's see if we can untangle things a bit:

Point-to-Point - The simplest bridging mode where one bridge unit talks to another. You usually enter the MAC address of the unit on the other end of the connection in each bridge's configuration screen. Manufacturers are pretty consistent in describing this mode and the way it's set up.

Point-to-Multipoint - This mode allows multiple networks to be connected. The modes used in the setup vary from manufacturer to manufacturer. SMC's 2682W, for example, requires one unit to be set as a "Bridge Master", and the other bridge units to be set as "Bridge Slaves". Linksys' WAP11 has you set one unit to Point-to-Multipoint, and the others to Point-to-Point mode, with the "Remote MAC address" set to the MAC address of the box set to Point-to-Multipoint mode. Confused? Wait, there's more...

AP plus Bridging (AP Client) - Manufacturers try to confuse you on this feature, but in theory, it's simple. It's basically a mode that sets a bridge to work with an Access Point, instead of another bridge. Manufacturers are fuzzy on the details of how this works, but one result is to create a wireless Client Adapter that has an Ethernet output. Another possibility is to create a network where your "local" AP supports wireless clients and wirelessly connects to an Ethernet based LAN, i.e., more than one Ethernet client. In this mode, however, the "remote" end of the connection can't talk to wireless clients. To do that you need to find a product that supports the next mode...

Wireless Repeater - Access Points normally require an Ethernet connection when multiple units are used to extend the range of a wireless LAN. Wireless repeating eliminates the need for the Ethernet cable, and allows multiple APs to both connect to wireless clients and to other APs that support wireless repeating. This is a very nice feature to have, but you'll pay for it, since it's typically only available on products priced above $500. A cheaper way to go is actually to connect two of the less expensive AP/Bridges together.

As if all the above weren't confusing enough, there are also products that allow devices that have only an Ethernet or serial connection to be added to your wireless network. 3Com calls theirs an Ethernet Client Bridge, while Linksys' product goes by the "Wireless to Ethernet Adapter" moniker (Linksys WET11). Client Adapter or Bridge? You decide!

And finally, just to keep things interesting, 3Com's Wireless LAN Workgroup Bridge will connect up to four Ethernet devices (you provide the hub or switch) into your wireless LAN.