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A Cup of Bandwidth: Bob Quietly "Borrows" Internet Service From Three Neighbors at Once

Status: [CLOSED]
By Robert X. Cringely
bob@cringely.com

Just as you probably are, I am the resident geek on my block. My neighbors on either side, not surprisingly, relied on me to help set up wireless networks in their Victorian homes. Right now, I can sit in my office, less than 100 feet from each of them, and see their WiFi access points strobing away on my computer screen. And like any hacker worth his bits, I of course left a backdoor into each network, "Just in case you need me to troubleshoot something." Yeah, right. But at least I told them. And neither the obstetrician nor the Presbyterian minister thought anything of it. I wondered how many more simultaneous connections I could make?

Three.

This isn't a story of war driving, more like war living. Many of us have relied from time to time on borrowed WiFi bandwidth. Right after we moved into our new-old house in Charleston, I remember cruising the streets late at night looking for a strong signal and an open access point just so I could check my e- mail. I have friends in New York who discovered an open access point right on the other side of their apartment wall and shamelessly used bandwidth for weeks from a guy who turned out to be a sysadmin. It makes you wonder what sort of security policies that fellow was following at work? None?

It is no big thing to find an open access point in almost any city. Sometimes people or businesses are just being generous, or they see offering free Internet service as a way to generate business. But most open WiFi connections are inadvertent. Schools are good targets, I've found, especially at night. Again, you have to wonder who sets up these networks? But what if I wanted a more robust "borrowed" wireless connection?

I decided to conduct an experiment, seeing how I could create an inherently reliable wireless Internet service through the use of multiple unreliable wireless Internet connections. DO NOT TRY THIS AT HOME (unless you want to). Remember, I am a professional.

If I was going to be serious about this borrowing a cup of Internet, then I'd need multiple connections -- something that is harder to do than you might guess. Most computers, for example, are connected to only one network at a time. It isn't so much the fact that there can't be multiple active connections, but that some of the housekeeping issues like DNS and SMTP servers get complex.

My home office is on the third floor under a mansard tin roof. I'm amazed that my neighbors' wireless signals can even get through to me but they do, though weakly. If I was going to reach out and touch a bunch of strangers, I'd need an external high-gain antenna -- probably several of them.

So I climbed out the window and found a place to attach a vertical length of pipe, atop of which I mounted three 8 dB patch antennas I had sitting around from my earlier experiment in aerial WiFi. The patches were clamped to the pipe, one atop another. I chose to use three because that would give me one each for channels 1, 6, and 11, giving maximal legal coverage.

It would be great if you could just plug three WiFi adapter cards into your PC, remove the pigtail antennas and attach a length of LMR400 cable, but I don't think it would work. Instead, I used three Linksys WRT54G 802.11g routers, re-flashed with Sveasoft firmware. My plan was to use each router as an Ethernet-to-Ethernet bridge, but actually acting as a client. An easier technique would be to use any of a number of WiFi gaming adapters, but I already had the WRT54Gs and figured that having the ability to increase their power might come in handy.

As it turned out, the power increase wasn't necessary, so if you can find a good deal on gaming adapters, jump on it. Remember, though, that my distances are still fairly short and this solution may not work in rural areas or even in your neighborhood.

The Sveasoft firmware gives a number of setup options, one of which is to set the box in "client" mode, which effectively makes it an external WiFi adapter. And that's about it if you are using just a single adapter. Remember to get the WRT54G as close to the antenna as possible, and to use LMR400 cable with no splices.

The harder job was to connect all three antennas to my network, the point of which is to provide redundant connections, if available, and possibly to spread the load over more than one connection so my theft wouldn't be be noticed. To do this I could have used my two Xincom Twin-WAN routers, but that would have required grabbing them from another place on my network and besides I wanted to find an alternate method of combining signals that might offer even further advantages.

I found my answer in Vicomsoft's Internet Gateway, an OS X product that would not only combine the four WiFi signals, it would also give me a firewall and web proxy server. I downloaded the free trial version and installed it in my old Apple G4/400 tower. This also required three 10/100 Ethernet cards, which I got locally for $15 apiece.

This is not a cheap solution. But if, like me, you have a lot of extra hardware sitting around, it can be a good one. I fired up the Mac and all those WRT54Gs and, sure enough, each soon found a WiFi connection (you have to monitor them separately through the Sveasoft interface because the Mac thinks it is just looking at Ethernet -- not WiFi -- connections, so Apple's AirPort software is not involved). I optimized the tuning by shifting each antenna's position on the pole until its signal peaked. Then I tightened down each antenna. Soon I had had each router looking at its own wide-open WiFi network, all of them connecting at speeds greater than the likely broadband connection speed at the other end.

Vicomsoft's Internet Gateway worked perfectly. I could fail one or two of the wireless routers simply by turning them off and the signal available to my network through the Mac's built-in Ethernet port never budged. I didn't play long enough for the proxy server to really show its stuff, but I don't doubt that it eventually would have, dropping even further my borrowed bandwidth budget. Every application I tried worked famously, even though I didn't really know how I was connected to the Net. Even VoIP worked fine, by which I mean I used Skype, but didn't try connecting either of my Vonage VoIP adapters.

Though I don't intend to keep this system up and running as a primary Internet connection, I certainly could. It has bandwidth comparable to my current mix of DSL and cable modems, costs nothing to run, and was a lot of fun to do. But it wasn't dead simple, either. DNS would have been a huge problem had I not already been running a Simple DNS server from JH Software. This easiest of all DNS servers to implement requires almost no customization at all and runs beautifully behind my firewall, providing DNS service to every machine on my network. It worked just the same over the bootleg wireless links.

Mail service might have been problematic, too, but that's easily solved through a remote smtp service, if you can find one, or just run your own mail server using dynamic DNS. Or maybe dynamic DNS wouldn't be so easy, given that every connection would tend to alternate as the Vicomsoft server polled all three connections.

What I haven't tested, and might, is how the array would work in other modes, supporting WDS mesh networking, for example, or acting as a sort of super-repeater. Using channels 1, 6 and 11, my total possible throughput was amazing. Since the Sveasoft firmware supports it, I might have been tempted to use the Japanese WiFi channel 14 to get four frequencies that don't step on each other at all. But in the U.S. at least, doing that would have been illegal.

Yeah, right.

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