wireless bridging options for home networks

If you have a computer with a standard wired Ethernet connection, and you want to join an existing wireless network, one option is a wireless bridge.  This may also help in a situation where your computer already has wired Ethernet and you have limited expansion slots or limited USB capabilities.

A wireless bridge might also be used if you have a laptop with a poor wireless antenna, or outdated/incompatible wireless (e.g. 802.11b in an all 802.11g network).

I am trying to avoid running cables in my house, so I'm using wireless wherever possible.

I have evaluated two wireless bridge options:

The Cisco Linksys WET54GS5 (Amazon.com - WET54GS5) is a traditional wireless bridge, including a 5-port switch.  However, it has been discontinued (I got mine on Ebay).

The Apple AirPort Express (Amazon.com - Airport Express) is a new entrant into the wireless bridging arena, but it supports only the non-standard WDS (Wireless Distribution System) protocol for bridging.  It has a single Ethernet port.  I will explain how to set up a WDS network between the Express and a D-Link DGL-4300 (Amazon.com - DGL-4300).

Other devices of this class are available, often presented as ways to connect game consoles that have Ethernet ports to wireless networks.

Summary

The WET54GS5 performs very well, but if you want to use DHCP, you must ensure you have a compatible DHCP server.

The AirPort Express can make a WDS connection (using manual configuration) with a D-Link DGL-4300 wireless router, but the throughput is 1/10th that of a non-WDS wireless connection.

Details

Linksys WET54GS5

The WET54GS5 is simple to set up, it is a traditional wireless bridge, which is to say, it participates as a node in your wireless network (including closed WEP networks), and allows any devices connected to its switch ports to communicate on the network as well.  I am using firmware v.4.92, September 22, 2005.

To get started, just decide whether you want the device to have a self-assigned fixed IP, or to acquire an IP via DHCP (I always pick self-assigned IPs for network devices as it simplifies troubleshooting).  Enter the SSID (or scan for networks to connect to), and enter the WEP password if necessary.  That's it, it will start routing traffic back and forth between the wireless network and the Ethernet ports.  It supports 802.11b and 802.11g

It supports advanced settings for the switch including traffic prioritsation and port mirroring, and it supports SNMP/RMON, but I will not cover those aspects.

The main downside is that the WET54GS5 has DHCP passthrough compatibility issues.  This will manifest itself as your connected devices being unable to acquire DHCP through the bridge.  Here are my observations on compatibility with DHCP servers:

Linksys BEFSX41 - compatible if a bit flaky (took a lot of bridge and laptop resets before it would work)
D-Link DI-524 - not compatible
D-Link DGL-4300 - compatible

Apple Airport Express

There are relatively few new entrants into the wireless bridging space.  The Apple Airport Express is interesting as it is a multifunctional device, allowing wireless bridging using WDS, as well as providing wireless audio (using iTunes).

What is WDS (Wireless Distribution System)?  It's a new way of making dedicated point-to-point wireless links.  Unlike the WET54GS5 above, which simply connects to the network like any other device, WDS requires that both the endpoint and the router know about each other, using the MAC addresses that are unique to the devices, and communicate on a fixed channel.

Apple supports WDS primarily for connection to their own base stations, the Apple Airport Extreme.  However I found that it was possible to set up a WDS bridge network between the Airport Express (with firmware 6.3) and a D-Link DGL-4300 (running firmware 1.8)

On the DGL-4300, the configuration is under Advanced->Advanced Wireless.  Set the WDS Enable checkbox.  It will helpfully give you a reminder if you have set the router to automatically find the best channel - for WDS only a fixed channel is allowed.  Enter the MAC address of the bridge device (in this case, of the Airport Express).  That's one end of the WDS bridge set up.

For setting up the Airport Express, I am using a Mac with Mac OS X 10.4 (Tiger), and Airport Utility 5.1 (I installed this from the Airport Express CD, it was newer than what was in my Applications/Utilities/ folder - the updated version 5.2.1 also works).  Operation on a PC should be similar.

You must use manual configuration to make this work with the DGL-4300.

Set the Airport Express up as you would normally for a wireless node - enter the SSID and WEP password, and set it to the same channel as the DGL-4300 (remember that WDS requires the two devices to share a fixed channel).  Select "Participate in a WDS network" as the Wireless Mode.

Then simply select the WDS tab, select "WDS remote", and enter the MAC address of the DGL-4300.

With this done, the pairing between the two devices is complete.  Any device plugged into the Ethernet port of the Express will be able to access the wireless network (I'm actually doing this right now).

Side note: The Airport Express does support two other modes of WDS operation (main and relay) but I will not cover them here.

However there is a huge downside for people with fast Internet connections, or wanting to use local network devices at high speed: the throughput maxes out at 800kbps.  (In case you're wondering, I have ten times that bandwidth to the Internet.)  Let's look at the numbers.  My theoretical max to the Internet is 8000 down/800 up.  I did multiple tests.

Here's what it looks like through Airport Express WDS, roughly 840/800

above using http://speedtest.cogeco.net/

Here's what it looks like directly to the DGL-4300 access point

And here's what it looks like through the WET54GS5 bridge

again using http://speedtest.cogeco.net/

I'm not sure why this performance problem is happening, but it makes Airport Express WDS mode of limited use for me (of course if your Internet connection is less than 800/800, and you don't need high-speed to local network devices, then it should be fine for you).

UPDATE 2007-12-07  Note: Although Cisco/Linksys has discontinued the WET54GS5, they have replaced it with a new model that offers equivalent functionality (bridging and 5 switch ports), the WET200 (I haven't tested it).

Comments

[Ken]

Thanks for the review. I currently have the DGL-4300 and wanted to get the Airport Express so that I could stream my music across the room to my stereo. I don't want to run another cable. I'm glad to hear that the Airport Express will do the trick.

[Richard Akerman]

I should clarify that for just playing music via a DGL-4300 and Airport Express, you don't need to set up WDS mode. You will need to set up the Airport Express manually, but just have it set up as a regular node (Wireless Mode: Join a wireless network), not as a WDS bridge. WDS bridge is only for connecting a non-wireless device to the network (e.g. if you had a laptop without wireless, you could plug it into an Airport Express set up in WDS bridging mode to connect to the network).

I will clarify this in my posting.