|Linksys Instant Wireless Ethernet Bridge (WET11)|
|Summary||802.11b to Ethernet bridge that can be used in AdHoc or Infrastructure mode to create interesting wireless/wired network combinations.|
|Update||11/13/02 - Take 2, Wrap Up on WAP11 vs. WET11. Corrected MPLS info
10/31/02 - Clarified Wrap Up on WAP11 vs. WET11
|Pros||• Can use other antennas
• Supports AdHoc and Infrastructure modes
• Superior radio performance
|Cons||• 10% WEP-enabled throughput reduction
• Can't be used as an Access Point
• No MAC Address Association controls
Linksys' new WET11 is causing quite a stir in the wireless networking world. Some say it's just a WAP11 stuck in AP Client mode. Others say it works great and wish it were weatherized for outdoor WISP-type use. So what's the real story? Has Linksys managed to come up with a one-product-does-all 802.11b solution?
Features and Geektails
Let's get the basics out of the way, then dive into the technical details. The WET11 is fairly small, having a footprint about an inch narrower than a stack of three CD jewel cases. The supplied single dipole antenna uses a reverse SMA (RP-SMA) connector and is jointed so that it can swivel 360 degrees and lock in 45 and 90 degree positions. You should be able to orient the antenna as desired, no matter how you position or mount the box.
The enclosure has no slots for mounting screws, though, and isn't really what I'd consider stackable, since the four LEDs (Power, Diag, LAN Link/Activity and WLAN Link/Activity) are on the top surface of the box. The single 10BaseT Ethernet connector, Normal / Crossover and Reset switches are all on the rear.
TIP: The Normal / Crossover switch is a welcome inclusion, since it will ensure that you can connect to either a switch / hub port or an Ethernet client device without hunting around for a crossover cable. Just use a normal UTP cable, make sure the device you're connecting the WET11 to is powered up, connect the WET and device together, and move the switch (wait a few seconds between moves) until the LAN light comes on.
The WET is not set up for Power Over Ethernet (POE), so if you're thinking of using it for WISP (Wireless ISP) applications, you'll need to roll your own. There are plenty of ways that you can add POE, including ready-made products like the SMC Power Injector or D-Link DWL-P100 Power Over Ethernet (POE) Adapters, or if you don't mind a little cutting and soldering you can roll your own.
The WET also isn't the only consumer 802.11b / Ethernet bridge available now either. D-Link has its DWL-810 and Hawking its WB320. But the WET11 seems to be the one getting a lot of attention, most likely because it's from Linksys, so let's see what makes it tick...
Let's Get into It
Updated 11/13/02 First, the WET11 is not a repackaged WAP11 Access Point, but is based on the Ubicom IP2022 Internet Processor. Earlier information from Linksys indicated that the WET used a technique called Multi-Protocol Label Switching (MPLS), instead of more conventional bridging code, but this turned out not to be true.
Whatever technique used, the WET's black-box magic should be invisible to the average user, who would see only the end result, i.e. the ability to have not just one, but up to 30 clients behind each WET11 connected wirelessly in the same subnet without any muss or fuss, and with the ability to share printers and files intact.
One key point about the WET11 that bears special emphasis is that it cannot be set to function as a standard Access Point, i.e. support wireless clients that are operating in Infrastructure mode. When you set the WET to Infrastructure mode, that means that it will look for an Access Point (or wireless router) to connect to, but not allow clients set to Infrastructure mode to connect to it. The difference may be difficult for wireless networking novices to understand (heck, I had to think about it for awhile before I got it!). So I'll be doing a companion article shortly that will explain how to use the WET11 in various network configurations, so you can get a better idea of what it can do (and how to do it).
In my testing, I was able to use two WETs in AdHoc mode to create a wireless bridge between two small Ethernet networks. The resulting network acted just like a single wired one, supporting Microsoft File and Printer Sharing and access to the Internet via my main router for multiple wired clients on both sides of the wireless WET11-to-WET11 bridge.
But when I set up another test network with one WET11 in Infrastructure mode connecting to a "normal" Access Point, I found that Microsoft File and Printer Sharing worked fine, but that I was unable to connect to anything outside my LAN, i.e. the Internet. At first I thought this was just the price you had to pay for the MPLS magic inside the WET11. But after reporting my results to Linksys, they asked me to hold off for a few days, and came back with a firmware update that fixed the problem. So be sure that you check the firmware revision of your WET11, and if it's not 1.3.2 or higher, go get the firmware update and run it. Unfortunately you'll need a Windows machine to run the update... another thing I hope Linksys fixes in future firmware releases.
NOTE: I missed the significance ot the WET11's ability (when set to Infrastructure mode) to connect to most (any?) Access Point, because I thought the WAP11's "AP Client" mode did the same thing. But several readers have pointed out that the WAP11 "AP Client" mode works only with other WAP11s in AP mode. I apologize for my oversight!