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MAN Trouble: So You Finally Have DSL and Tons of Bandwidth, but Don't Be Surprised If Your Metropolitan Area Network Lets You Down

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

Maybe it's because I grew up in the Corn Belt, but the lessons of hybridization were drilled into my young brain back in the 1960s through a series of filmstrips and 16mm movies about the glories of American agriculture. In case you didn't come from the Corn Belt, here's the secret of hybrid corn. Hybridization is just crude genetic engineering in the Gregor Mendel tradition of crossing the biggest, hardiest, fastest-growing varieties of corn (or any other crop) until you end up with SUPERCORN. SUPERCORN is so much better than regular corn it yields more bushels per acre and is more resistant to disease, it is soon the choice of every corn farmer everywhere. If you aren't raising SUPERCORN, you aren't making as much money as you could. Soon there are millions of acres of corn that is not only the same variety, but since it is derived from a single master plant it is genetically identical. And that's the dark side of hybridization, because if a new disease comes along that does bother SUPERCORN, it affects the entire crop. There is always the risk that the entire crop will die all at once.

Which brings us to the Love Bug, last week's computer virus furor that caused billions of dollars in damage. Hybridization comes into this drama because the I Love You worm isn't just a computer virus or a PC virus or a Windows virus or even an e-mail virus. I Love You is specifically a Microsoft Outlook/Visual Basic virus. It takes advantages of features in this SUPERCORN of e-mail programs to cause damage to the greatest possible number of users. But if, like me, you are a Eudora user or a user of any e-mail program other than Outlook, I Love You had no impact at all. This is a strong argument for genetic diversity in software because what made the Love Bug so costly was Microsoft's success at getting people to use its software. I wonder when the lawyers will pick up on this particular aspect of the problem and start filing yet another round of class action lawsuits?

Enough of this Love Bug distraction, let's get back to my look at small companies helping to define both the network of the future and the New Economy. Last week was Arraycomm, a company that hopes to use smart antennas to bring wireless high speed networking to all of us. This week's company is another 'A' — Alidian Networks, which hopes to change the way optical networks operate in major cities.

Ever since Sprint started dropping that pin to promote its fiberoptic network, there have been misunderstandings about both the possibilities and problems of fiber networking. Here are a number of things everyone knew that were wrong. For example, we used to hear a lot about what was called "dark fiber." These were optical fibers buried underground, but not turned on. The idea was that it didn't cost all that much more to throw a few extra fibers into the conduit before covering it over with dirt. We had so much dark fiber, we were told 10 years ago, that the U.S. would never run out of available network capacity. Yes and no. Back then, we didn't envision the Internet bandwidth requirements of today, but much more importantly, we pretty much ignored the fact that the major reason that fiber was left dark was not because we didn't need the bandwidth, but because it cost too much to turn on the light. Placing fiber in a trench is nothing compared to the cost of installing the equipment at both ends of the fiber to send and receive optical signals. THAT's where the real expense lay and why that fiber stayed dark.

Then a couple years ago it began to look like lighting all the dark fiber still wouldn't be enough. With Internet bandwidth doubling every four to six months, it suddenly became likely that we'd simply run out of glass after all. Then came Dense Wavelength Division Multiplexing (DWDM). This new technique uses more than one color of light to carry more information down the same fiber. DWDM adds an extra channel for each additional color up to a total of around 32 channels right now. So the same fiber can, with DWDM, carry 32 times as much data. If you do that math, however, you'll see that even DWDM only buys us 30 months of breathing space, which is why new trenches continue to be dug and new fiber laid all the time.

DWDM would be great if it worked as well from end to end on the network, but that's not the way it is done. DWDM is intended for long-haul Internet backbone connections and doesn't allow the mixing of protocols on a single color-channel. So you can't throw together gigabit Ethernet, Asynchronous Transfer Mode, or any of the other popular protocols on a channel. The result of this is a dilemma. DWDM brings dramatic increases in bandwidth to backbone connections at the same DSL is bringing cheaper, faster bandwidth to local connections. What's left out is the link between the backbone and the local loop the Metropolitan Area Network, or MAN. MANs, which are typically fiber rings running the SONet protocol, have been generally shut out of these recent bandwidth surges. The only sure way to increase SONet bandwidth is by adding more fiber rings, which has us back to digging trenches and laying fiber. This so-called Metro Area Gap is a serious and emerging problem for the Internet.

But now comes Alidian, a Mountain View, California-based company founded generally by refugees from Bay Networks and Lucent Technology. Alidian calls its technology an Optical Service Network (OSN). If OSN does everything Alidian says it does, it not only brings the advantages of DWDM to Metropolitan Area Networks, it also allows the mixing of protocols on single DWDM color-channels AND allows the rapid reconfiguration of services so that connections can be established, dropped, or changed in their capacity at will, something that SONet hasn't been able to do. And since OSN runs the many protocols in their native forms rather than encapsulating them in another type of packet, two transformation stages are eliminated making the network even faster.

Does OSN work? Beats me. But it is available for sale right now, so I'd say it is very likely to work. But don't expect to buy OSN at Radio Shack, because it is generally aimed at telephone companies and big Internet outfits. And don't expect Alidian to survive for long in a market that's being split between aggressive players Cisco, Lucent, and Nortel. One of these three will probably end up buying Alidian no matter how much it costs.

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