D-Link AirPlus Enhanced 2.4GHz Wireless Range Extender
April 04, 2003
Got range problems? D-Link hopes to solve it with this extender. It can work as an ordinary access point, but the real value is in the device's repeater mode.
One of the frequent challenges encountered when setting up a WLAN is limited range and the resultant dead spots where the wireless signal can't reach. You needn't live in a mansion to have this problem -- depending on the configuration of and materials used in your abode you may suffer signal propagation problems even in a relatively small space. This is also likely if you're trying to extend your home wireless network outside the confines of your home (like to your backyard).
D-Link offers a way to ameliorate this problem in its AirPlus Enhanced 2.4 GHz Wireless Range Extender (DWL-800AP+). Although the device can function as an ordinary access point, its real value is in the device's repeater mode, which promises to considerably extend the range of your wireless network.
The good news is that the DWL-800AP+ is based on the TI enhanced 802.11b chipset, so it's capable of handling bandwidth of 22 Mbps (and 256-bit WEP encryption). The bad news is that the device is currently only compatible with certain D-Link products. D-Link says that third-party products will eventually be supported via firmware updates, but so far, the few I had on hand didn't work with the DWL-800AP+. The chances are probably better with another TI chipset-based device.Given the unambiguous function of the DWL-800AP+, I expected that the setup and configuration of the unit would be relatively straightforward. It wasn't.
Like many products nowadays, the DWL-800AP+ employs a Wizard for the initial configuration. To configure it as a repeater, you specify the MAC address of the remote router. If you're like me, you might retrieve the MAC address of your router from the underside of the unit. That would be a mistake, because that is probably not the right one. An access point has two interfaces (LAN and WLAN), so it will in turn have two MAC addresses. Moreover, a broadband router will have a third MAC address for the WAN interface, as was the case with my D-Link DI-614+ router.
The DWL-800AP+ requires the MAC address from the remote device's LAN interface to repeat its signal, though it does not specify this anywhere it its documentation. Having hastily used the MAC address printed on the router, (it was the WAN interface address and thus the wrong one) I wasn't initially able to connect to the repeater with my wireless client.
After a bit of head scratching and trial and error, I realized the error of my ways and finally entered the correct MAC value. This did cause the DWL-800AP+ to show its face during a site scan. However, although I was then able to successfully connect to the repeater, I had no IP connectivity to my LAN or the Internet beyond it.
More head-scratching ensued, but to make a long story short, the culprit turned out to be a bug in the firmware version of the DI-614+ router I had--specifically, version 2.18. The kicker is that there are actually TWO versions of this firmware. One is dated 2/28/03 and is the one with the problem. The other is dated 3/14/03 and works fine. To make sure you get the good one, go to D-Link Support's product page directly and drill down to the DI-614+, under "Gateways." As of the time of this writing, if you go to the support page and then look up DI-614+, you are only offered the older, malfunctioning version.
Aside from the setup hassles I experienced, there is one other potential downside of the DWL-800AP+. Once configured as a repeater, it becomes transparent to the network; you can't ping it, and you can't access the browser configuration. As a result, you'll have to directly connect to the LAN port to change configurations -- something to remember if you mount the device in an inaccessible location.