Wednesday, November 30, 2005

I'm so totally Extreme  

This weekend I finally upgraded my wireless network at home. For the past three or four years I've been using a second generation AirPort base station, which was 11Mbps with 40-bit WEP. It's been thoroughly out-of-date for a while now, but it met my needs, was rock-solid, and worked like a charm so I didn't feel the need to upgrade. And after all, 5.5Mbps is still more bandwidth than my real-world connection to the internet, so I knew that switching to the higher-bandwidth AirPort Extreme wasn't going to make a difference in simple web browsing.

But this week I finally broke down and made the jump to the latest and greatest. A combination of two things finally pushed me over the edge:

  1. I've been doing a lot more work lately that involves transferring things between machines in my office. Local transfers from machine-to-machine are where 54Mbps can really make a difference.

  2. The signal strength wasn't so great everywhere in the house, and I wanted to use WDS with an AirPort Express to extend the range of my network.

Another small factor was that if I upgraded, I could have iTunes send its output directly to my stereo via AirTunes. Personally I think AirTunes is kind of a gratuitous and somewhat goofy feature. It's certainly not enough to make me spend a couple of hundred dollars on new equipment. But I have to admit that once the other (much better) reasons pushed me over the edge, I was looking forward to giving it a shot.

So I made the plunge and bought an AirPort Extreme Base Station and an AirPort Express, and hooked everything up.

Perhaps because I like pain, or maybe just because I wanted to see if it would work, I decided to set up the AirPort network from a Windows laptop. Okay, the real reason is that my old TiBook recently died from catastrophic hinge failure and I couldn't find where I'd left the charger for the iBook, which meant that I didn't have a wireless-capable Mac handy.

Setting up the main base station worked like a charm. I plugged it in, ran the Windows version of the admin utility -- which I have to say is really very nice -- and saved the configuration from the old base station into a file on my desktop, then imported it into the new base station. Happily, it copied out my DSL PPPoE account and password. In the process I upgraded the wireless security from WEP to WPA, set my server box as the default host (DMZ), and configured the base station so that it would syslog to one of my machines. Restarted the base station, connected with the new password, and everything worked flawlessly. Great!

Getting the Express set up to extend my network, however, was a little bit trickier. I started at the obvious place with the AirPort Express Assistant for Windows. But somewhere in the middle of the setup as it jiggled Windows XP and base station settings, it failed while reading from the base station with an error -4: "bad param". Tried again several times with the same result. Hmmm. Not so great, and virtually impossible to diagnose what went wrong.

Why, no problem, says I, I'll just configure it directly with the admin utility.

That's much easier said than done. I did get it done in the end, but it certainly didn't go as smoothly as I was hoping it would. There are a lot of non-obvious details that need to be just right before everything works. Most of the answers can be found in the admin utility's help if you know where and how to look, but it takes some digging.

Here are some tips from my experience with setting up WDS manually:

  • Terminology. You have the main, relay, and remote stations.

    • The main base station is the one connected to the internet via Ethernet.
    • Relay stations connect between base stations, and do not have an Ethernet connection.
    • Remote stations provide services to clients, and do not have an Ethernet connection.
    As far as I can tell there's not a lot of practical difference between relay and remote, since both main and relays can be configured to accept client connections too. It may be the case that remote stations are able to dedicate more bandwidth to clients than main or relay stations, but I'm not sure about that. In any event it seems more like something you'd only be concerned about for a large-scale installation with lots of client computers and extremely heavy traffic -- I doubt it matters for home networks.
  • MAC addresses. Before you start, you need to write down the AirPort MAC addresses of all the base stations involved. It's on the outside of the base station, or you can get it from the base station chooser. If you do that, though, remember that the stations will be broadcasting different wireless networks at first. So you need to join each one in turn, then select it in the chooser (no, not that chooser) and write the AirPort MAC address down somewhere.
  • "Distribute IP addresses" should only be set on the main base station, not on relays and remotes. Thankfully, the admin utility warns you about this.
  • All stations must use the same channel. Pick a channel (I like 3 and 10) and set both base stations to it. The admin utility tells you that you can't use 'Automatic', but neglects to mention that all base stations have to use the same channel -- which is kind of an important detail.
  • Set up the main base station first, then relays, then remotes. When you set up a WDS main base station, you'll need to enter the MAC addresses for the WDS remote and relay stations that will be allowed to connect. It doesn't work if you go the other way, because a remote base station won't be able to connect to the main base station until the main base station has been configured.
  • Use different SSIDs (network names) at first. It doesn't matter whether base stations connected by WDS have the same network name or different names. Toms Networking recommends that you use different SSIDs, while Apple's Designing AirPort Extreme Networks for Windows recommends on page 38 that you use the same SSID. But if you plan on giving them the same name eventually, don't start out that way! Give the networks different names so that you can be sure you're connecting to the right base station when testing to make sure that it works. Once everything is working you may then decide to set them to the same SSID; it's up to you.
  • Know where the reset button is. If you make a mistake and can't find one of the base stations on the wireless network anymore, hold down the reset button for about seven seconds (until it starts flashing quickly) to give it a hard reset. The button is recessed, but can be pushed with a paperclip, staple, ball-point pen, or stereo miniplug.
  • Double-check all of your settings if you are importing settings from an older base station to a newer base station. At one point in the process I noticed that my main base station's transmission strength was apparently set to the lowest setting -- 10%, instead of 100%. I can only speculate about why that happened. The older base station didn't have adjustable signal strength, so perhaps it pulled in a zero value rather than the default of 100% when it imported my old configuration to the new base station.

Phew. Anyway, after a little bit of futzing around, I've got it working and I'm happy. The speed on the local network is much better, and the WDS extension has made the signal strength much stronger throughout the house. It wasn't too much of an ordeal and I got it all sorted out in an hour or two, but it was certainly harder than it should have been. Apparently I'm not the only one who thinks so, either.

But as a bonus to reward all my hard work, I can now have iTunes play through my stereo via AirTunes. Dude, I'm like so extreme.


  • Anonymous said...

    I love having the airport express hooked up at my office its awesome.

  • Anonymous said...

    good write-up. had the same sort of issues and i left site after an hour to get back to it...thank god, i saw your site to drive me out of insanity...sometimes simple things in life are the hard ones to sort out..cheers dude