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Power networks

Your home and office are already wired for networking.

Not long ago, PC networking was enough to make the average computer user blanch. We’re not talking about technophobes here, either. Throw some other Mensa-level computer tasks at one of these tech-savvy types, and they’d take them in stride. Install a new graphics card or RAM? Child’s play. Program a few Excel macros? Easy as falling off a log. Set up a database? Sure, but what should I do after my coffee break? But talk about networking and the smug grin turned into a panic-stricken rictus.

It wasn’t just the business of setting up IP addresses, access, security, and sharing rights. Over the past five years, Microsoft has been doing a pretty good job of automating that kind of machine-level configuration in its operating systems. The real headache was wiring. Dragging yards of blue Ethernet cable through wall cavities meant summoning an electrician and vacuuming construction dust out of your office for the next few months. Wireless networking wasn’t the ideal answer either–sure, wireless networking is fine for notebooks, but it wasn’t meant for desktop computers, and it tends to slow down a lot as you move away from the wireless nodes.

Last year, a new networking standard appeared that took the wiring problems out of networking. The HomePlug PowerLine Alliance standard 1.0 uses Ethernet networking standards over the wiring that every home and office has–power lines. Stick a HomePlug adapter on any two power outlets in the same house or office, plug a PC, router, or other networkable device into the HomePlug adapters, and bingo! You have a network. A little fine-tuning in the operating system, and you’re sharing files and Internet access like a pro.

Naturally, the reality doesn’t always live up to the promise, but over the past six months, I’ve looked at HomePlug adapters from five of the 10 vendors who make them, and I’ve been impressed. I’ve installed networks in 80-year-old houses and newly-wired office buildings alike, and while it hasn’t always been a smooth experience, my smug grin hasn’t yet frozen completely. So does that mean you should consider using HomePlug instead of wiring a building for Ethernet networking? Read on and decide for yourself.

Plugging into PowerLine networking

Modulating network signals over 110V powerlines is nothing new. Proprietary systems from x10, IBM, and Phonex convert power outlets into phone outlets or remote control points for home gadgets and lights. But until the HomePlug Powerline Alliance came along and signed up chipmakers and network adapter makers like NetGear, Linksys, and Siemens, there had been no standard for Ethernet-like computer networking. The HomePlug Alliance’s 1.0 standard certifies adapters from at least 10 manufacturers that will work together to network using accepted Ethernet protocols at data rates up to 14Mbps.

Powerline adapters come in two styles–Ethernet RJ-45 and USB. You plug Ethernet-style adapters into PCs, Macs, network-enabled printers, or broadband routers to hook them up. You can install Windows-based driver software if you wish, but it’s not necessary for small networks, unless you’re using USB-based PowerLine adapters.

Using these adapters as a bridge between two networkable devices is pretty flexible–you can share printers, files, and broadband network access. Broadband sharing is easiest with a broadband router between your cable modem and your computers-you can hang a powerline adapter off one of the router’s sockets to expand your broadband access to computers in other rooms.

Who makes HomePlugs?

The HomePlug alliance lists the manufacturers of chipsets, reference models, and commercially available network adapters at its site. Of the 10 manufacturers listed there, I’ve personally tested USB and Ethernet models by Linksys, NetGear, Phonex, Siemens, and Gigafast, and haven’t found a real dud in the bunch.

There are some minor differences in the data transfer rates of the various adapters–in general, the USB devices transfer data more slowly than the Ethernet ones, and in my informal tests, the Linksys, NetGear, and Gigafast models have been a little slower overall. But the speeds and feeds are negligible. More important to me has been the bulk and design of the units. Linksys’s adapters are vast and bulky by comparison to the rest; Gigafast’s are small and boxy. The best design I’ve yet seen is from Siemens-their SpeedStream PowerLine Ethernet adapter works like a DC power adapter, but with an Ethernet cable sticking out of it instead of a power cord.

Powerline network pluses

According to the HomePlug Powerline Alliance, powerline networks have a range of 1,000 feet of power cable-much better than the direct-line working range of Wi-Fi 802.11b and 802.11a’s 150 feet. However, electric cabling tends to wind around nooks and crannies of the architecture, so bear in mind that 1,000 feet of cable will be much less than 1,000 feet of direct distance between power outlets.

That said, I’ve set up networks between the attic and basement of a four-story house that crank data at up to 6Mbps. That’s much less than the theoretical data transfer limit of 14 Mbps, but data transfer rates never reflect the amount of useful data transmitted. Live data is always padded out with signaling overhead and error correction codes to ensure that nothing gets lost on the way. The important thing to remember is that powerline networks outpace most common wireless networks (802.11b tops out at 11Mbps, and in practice, typically chugs along at one-tenth that speed).

And for data security, HomePlug uses 56-bit DES encryption, which beats Wi-Fi’s RC4 algorithm with a stick.

Downsides to Powerline networking

But powerline networking isn’t perfect. The adapters aren’t the cheapest on the market–adapters I’ve tried retail at around $99 per computer. So a four-PC powerline network should cost around $400–more than an Orinoco Wi-Fi network, with a $150 base station and $50 adapters.

Fifty extra bucks shouldn’t stop you from adopting a technology that’s otherwise a good match for your needs. But there is a limitation that’s not going away soon: the number of computers you can hook up. The Intellon chipset that all HomePlug 1.0 adapters use have slots for only 16 addresses–that means that only 16 devices can co-exist on a HomePlug network. All but one of the manufacturers can’t exceed that number–add a 17th device to a network and it won’t even register. Phonex QX-201 NeverWire 14 adapters can support more than 16 devices on a network, but only 16 of them can be active at once.

To small or home offices, 16 devices is plenty. But there’s another less well-known limitation. If you don’t install Windows drivers on each device with a HomePlug adapter attached, you’re limited to only three devices per network. This severely limits Macs, routers, Ethernet printers, and other devices that can’t run Windows drivers.

Another problem for Macs is that they can’t program new passwords into HomePlug adapters. These adapters use a pretty powerful encryption technique–56-bit DES encryption–and all adapters come with the same default password key. This means that they’ll all work together out of the box. But to change passwords, you must use a Windows-based program to load a new encryption key onto an adapter that’s directly plugged into the computer with the software-which rules out Macs that aren’t running Windows emulation.

Powerline surge

The biggest x-factor in powerline networking is that of the powerlines. AC power circuits are a dodgy medium, prone to spikes, surges, and periods of low charge called brownouts. That said, during extended tests of HomePlug Powerline adapters, I’ve had remarkably few problems. In six months, maybe three or four times the shared Internet connection has failed on one of the systems.

Only one of the major manufacturers I’ve tested provides halfway decent network diagnostic tools. Phonex’s NeverWire products have no installation disks in the box, but you can download an excellent network diagnostic program that shows you all manner of connection data–ranging from the MAC addresses of each adapter to the data throughput from each node on the network.

When your only other options are messing around with Windows’ own IP Configuration program (from the Start menu, you select Run and enter either winipcfg or ipconfig, depending on your Windows version), or the command line program ping (after which you type in the IP address of a node on the network and press Enter), the NeverWire utility is a welcome change. It’s my personal choice for melting away the rictus effect of network problems.

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