Fast and Loose with Wireless Networking
Whenever Tonya and I move, two of the early priorities are to create an internal network for file sharing and printing, and to bring up an Internet connection. Looking back on our last few moves offers a trip through networking technology.
When we moved to Seattle back in 1991, the network between my SE/30, her Macintosh Classic, and our QMS-PS 410 laser printer came up quickly via phone cables carrying LocalTalk. The Internet connection was trickier, requiring me to find a host that would give me a UUCP feed (Unix to Unix CoPy, an old form of transferring information around the Internet). When we bought our first house two years later, I didn’t have to change anything with the UUCP connection (though I later switched to TCP/IP-based Internet access via SLIP, then PPP, and then a dedicated 56 Kbps frame relay connection). But for the first time, we had offices in separate rooms, which meant that our interim LocalTalk network required patching several phone cables together with extra PhoneNet connectors to cover the distance (for some reason, our cats decided they liked to sleep right on top of the cables). The next move was to a much larger house, and for that I bought a 50-foot phone cable for the interim LocalTalk network until we got someone to pull Ethernet cable throughout the downstairs offices and to the kitchen upstairs. At least the network worked there – that was the house where we suffered with a single phone line for voice and dialup Internet access for six months, and waited another three months before US West (now Qwest) was able to provide a 56 Kbps frame relay connection.
The days of LocalTalk are long past, and the concept of living with only dialup Internet access for more than a very short while fills me with dread. So for the latest move to Ithaca, New York, I resolved to set up a proper network and Internet connection right away. But as they say, the best laid plans… We’ve been in the house for over two months, and although I managed to bring up networking and Internet connectivity quickly, the whole setup feels like it’s held together with spit and baling wire. Or at least it would be if there were any wires involved.
Go Wireless — Wiring a house can be difficult and expensive, and I hate drilling through walls and floors if I can avoid it. Since the four Macs that Tonya and I use regularly (my Power Mac G4 and iBook (Dual USB), her blueberry iBook, and the PowerBook G3 Series that serves as our kitchen Mac) are all capable of using the 802.11b wireless networking technology that’s at the heart of Apple’s AirPort, I figured I’d use our AirPort Base Station to make that connection and use wired Ethernet for our older machines. Bringing our LocalTalk-based LaserWriter Select 360 into the mix would be done via Apple’s unsupported LocalTalk Bridge running on one of our older machines that supports both Ethernet and LocalTalk. And indeed, that all works like a charm, though our cat Cubbins doesn’t get the pleasure of sitting on any networking cables.
Then came time to add in an Internet connection. I have two options, a cable modem and, more interestingly, a long-range 802.11b wireless connection. My master plan is to use both of these connections. They’re both inexpensive, so I’d be paying less for two megabit-plus connections than I was paying in Seattle for a single 56 Kbps frame relay connection (even without ISP fees). But neither guarantees reliability, and losing connectivity for even a short while at the wrong time can be maddening in my position.
I haven’t yet figured out how all this will happen, though I’m still investigating using Open Transport’s hidden single-link multihoming capability of answering to multiple IP numbers, running two separate AirPort networks, or doing some fancy routing. My tardiness in figuring all this out is due to needing to set up the long-range 802.11b wireless connection (I’m still learning about the necessary antennas, which can be used with normal 802.11b gear to extend range significantly). Of course, I also have to get my work done every day and finish moving in, so in the meantime I’m using just the cable modem connection, and therein lies the rub for my wireless network.
It turns out that this particular cable modem service memorizes the MAC address (the address of an Ethernet card) that connects to it and provides it with an IP address via DHCP (Dynamic Host Configuration Protocol), which means it can’t be plugged into an Ethernet hub which lacks a MAC address. One seemingly obvious solution is to plug it directly into the AirPort Base Station’s Ethernet jack and serve just our wireless-capable computers temporarily. But that doesn’t work for reasons I don’t entirely understand yet, even after reading Apple’s somewhat confusing Knowledge Base documentation and trying all possible configurations.
Various Alternatives — Clearly I needed another approach, and since I knew I could get the cable modem working if it was plugged directly into one of my Macs, I immediately thought of running IPNetRouter from Sustainable Softworks on our Performa 6400 with a pair of Ethernet cards (which I happened to have lying around) in its two PCI slots. First came some fussing with how DHCP works (if you ever open your TCP/IP control panel and see an IP address starting with 169, that means your Mac hasn’t gotten a real IP address from the DHCP server – try switching the connection from Ethernet to PPP and back again to force a retry). Then I had to fiddle with the two elderly Ethernet cards, one from Farallon and one from Sonic Systems, since they conflicted with certain combinations of drivers and slot order. Eventually, though, I got it all set up and working with IPNetRouter (which was itself easy to configure once I had everything else working properly). I then plugged our other wired Macs into the Ethernet hub along with the AirPort Base Station, which I set so all it did was bridge between the wireless and wired networks (all the Macs used manual addressing with IP addresses in the private 192.168.0.x range). Plugging a PhoneNet connector into the Performa 6400’s Printer port and enabling LocalTalk Bridge brought the LaserWriter into the mix, and all was happy. Here’s what it looked like:
Cable modem — Card A | Card B — Hub — Wired Macs
PhoneNet cable | |
via LocalTalk Bridge | AirPort Base Station — Wireless Macs
LaserWriter Select 360
There was only one problem. I had managed to force the two Ethernet cards’ conflict into an uneasy truce, but skirmishes still broke out every few hours that took down the Internet connection. A restart fixed the problem, and since I was desperately trying to get other things done, I hacked around the problem by installing Maxum’s PageSentry, telling it to watch our main Web site, and if it lost contact to restart the machine via a one-line AppleScript. It wasn’t elegant, but it kept the connection up 99 percent of the time.
It worked for a while. After about three weeks, late on a Friday afternoon as I was pushing to finish an article, one of the Ethernet cards threw in the towel. At first the connection would go down after only a minute or two, then the Performa 6400 refused to boot at all until I removed one of the cards. Desperate to bring something back up, I realized that I actually had other Macs with multiple Ethernet cards, since AirPort cards speak Ethernet too. So I connected the cable modem’s Ethernet cable to Tonya’s iBook, turned on the Software Base Station feature of Apple’s AirPort software, reset my Power Mac G4 to use DHCP in the TCP/IP control panel, and managed to finish my work for the day. Though functional, this setup wasn’t ideal, since neither the wired Macs nor the laser printer could be on the network. Plus, when Tonya came home, she expressed a certain level of displeasure at her iBook being tethered to the cable modem (my iBook was off at Apple getting a new keyboard because of a partially broken keycap). But, here’s what that configuration looked like:
via Software Base Station
Cable modem — Ethernet AirPort — Wireless Macs
Our kitchen Mac PowerBook G3 was the only other dual-Ethernet Mac available, since although my Power Mac G4 had an AirPort card, on-board Ethernet, and a free PCI slot for an Ethernet card, moving its 20" monitors into the same room as the cable modem is not a job to be taken lightly. The unusual thing about the PowerBook G3 is that it uses an old Farallon SkyLINE 2Mbps card for access to the wireless network. I wasn’t sure if or how I’d be able to work that into the system, since Farallon’s software has no provision for acting like a base station.
In the end, though, it turned out to be easy. I set the SkyLINE software to create a computer-to-computer network (which it calls "ad-hoc"), configured IPNetRouter as I had on the Performa, and plugged a PhoneNet connector into the Modem/Printer port and installed LocalTalk Bridge so we could print (plus access the wired Macs slowly, since all of them can also use LocalTalk). I had to reset my Power Mac G4 back to a manual IP address, but everything worked, albeit a bit more slowly due to the SkyLINE card’s lower throughput and the increased reliance on LocalTalk. Here’s what this network looked like:
Cable modem — Ethernet | SkyLINE — Wireless Macs
PhoneNet cable |
via LocalTalk Bridge |
LaserWriter Wired Macs
Not all was perfect, though. Tonya’s iBook worked with the new setup, except that the SkyLINE card was powerful enough to reach only the door of her office, not the desk six feet further in (this is the farthest room from where the PowerBook had to sit next to the cable modem). Then, after a few days of this setup, my Power Mac G4, also on the opposite end of the house and up a story, stopped being able to receive the signal from the SkyLINE card. I have no idea why, but I was able to solve the problem by moving the PowerBook G3 a few feet closer.
The next wrench thrown into the works was my doing. During all of this, I’d ordered a 14 dB Yagi antenna and appropriate cabling to bring up the long-range 802.11b wireless Internet connection. To test the gear when it came, I got the bright idea of removing the Lucent WaveLAN PC Card that’s inside Apple’s AirPort Base Station and using it in the PowerBook G3 (the only PC Card-capable machine I have) with the AirPort software. The WaveLAN card was ideal for this test, since it has an antenna jack, unlike Farallon’s SkyLINE card, and it was external, unlike Apple’s AirPort cards. It was good I did the test, since although the antenna worked in many locations (I drove around the neighborhood with the PowerBook hooked to the antenna), it didn’t pick up a strong enough signal at our house. A different antenna I’ve ordered should work better.
With plans for the long-range wireless network temporarily quashed, I set up the PowerBook as it had been before. However, I ran into another vexing problem. I replicated the setup exactly, down to the placement on the counter, and it worked fine with the iBooks (mine had returned from Apple in the meantime). But my Power Mac G4 couldn’t pick up the signal reliably. I tried switching the PowerBook G3 to the Lucent WaveLAN card and using Software Base Station, but that didn’t help either. The only thing I found that worked was to set my iBook (Dual USB) up with Software Base Station (as in the Network #2 diagram). Since the iBooks actually have two antennas, one of which is always used for transmitting (either of the two may be used for receiving), my problem was solved. Of course, there was no way to include the wired Macs (which aren’t essential, as you may have realized) or the laser printer, but we worked around that problem temporarily with a USB-based Epson Stylus Photo 870 that we normally use only for color printing.
<http://developer.apple.com/techpubs/hardware/ Developer_Notes/Macintosh_CPUs-G3/ibook/ ibook-33.html>
After a few days, my Power Mac G4 once again stopped getting decent reception, and none of the small changes I could think of made any difference (Tonya’s iBook and the PowerBook G3 continued to work fine during all of this). Clearly, the only solution was to lessen the distance, so I took a deep breath and started drilling from the server room (where the cable modem must live) into the floor of my bedroom closet on the second floor. It was, as I anticipated, much harder than it should have been, thanks to a thick and well-insulated ceiling/floor, but eventually Tonya and I were able to snake Ethernet and phone cables up from the server into our bedroom. From that vantage point on the same floor as my office, the Power Mac G4 had no trouble picking up the signal from the iBook, and even when I switched back to the PowerBook G3 and SkyLINE card (as in the Network #3 diagram), the reception remained fine.
What’s He Smoking? At this point, you’re probably wondering why I haven’t thrown a little money at the problem and bought a broadband gateway like Proxim’s NetLINE Wireless Broadband Gateway, Linksys’s EtherFast Wireless AP + Cable/DSL Router w/4 Port Switch, or one of the others that Glenn Fleishman looked at in "Flying into Other AirPorts" in TidBITS-578.
I’m not just being cheap. For one, I learn best via repeated trial and error, and this effort has given me a greater appreciation of just what IPNetRouter and Software Base Station can do, not to mention the fuzziness of 802.11b wireless networking. Plus, I know that I’ll need additional hardware when I bring up the long-range 802.11b wireless Internet connection, and I’m trying to avoid buying hardware that will turn out to be unnecessary. A networking expert might be able to diagram everything and be relatively assured of having the final network look similar, but I’m not at that point yet when mixing wired and wireless networks and two separate Internet connections. I prefer to move slowly, using what I have on hand, until it becomes clear what additional pieces are necessary. I’ll be sure to pass on more about this network setup as I figure it out.