POWERLINE HARDWARE ANNOYANCES

LOOK FOR THE HOMEPLUG LOGO

The Annoyance:

I find that powerline devices have a wide range of prices, and they have different specifications on the box. Some say they operate at 12 or 14 megabits per second, others are slower (and cheaper). Is there a difference?

The Fix:

Yes, and this is another one of those cases where you get what you pay for. The cheaper, slower devices aren't using today's standards for powerline network technologies. Look for the HomePlug logo on the box, which means the device is built to the specifications of the HomePlug Powerline Alliance (http://www.homeplug.org).

UNDERSTANDING POWERLINE BANDWIDTH

The electric wires running through your walls can do more than deliver power to electric appliances. A great many wires, operating at different frequencies, are enclosed in the electric cable. In fact, the range of frequencies is split into 84 separate carriers.

Multiple technologies exist for sending computer data along the carriers, but the most reliable is the technology endorsed by the HomePlug Powerline Alliance. This industry group has developed the specifications for accessing the bandwidth of power lines by using orthogonal frequency-division multiplexing (OFDM). You can learn more about the HomePlug Powerline Alliance, and the specifications for powerline networking, at http://www.homeplug.org.

OFDM sends packets of data along several of the carrier frequencies simultaneously, which provides more speed and reliability than previous powerline technologies. Today's powerline network devices operate at 14 mps. Specifications are being considered and tested for powerline communication speeds of 100 mbs.

If a power surge or any other problem disrupts one of the frequencies, the data switches to another carrier automatically. The carriers carry data, not power, so your electric bill is not affected by your use of powerline devices.

POWER STRIPS AND POWERLINE DEVICES

The Annoyance:

Finding free outlets in a room with a computer and peripherals can be difficult. I have power strips plugged into outlets to handle the multiple devices. Can I plug the powerline adapter into a power strip?

The Fix:

Maybe, maybe not. Sorry, but this question doesn't have a clear-cut answer. My experience differs from the recommendations of powerline device manufacturers. I've plugged powerline adapters into power strips without problems. The manufacturers' instructions all say that this action is not recommended, and they advise you to plug the adapter directly into the wall. They claim the circuitry in the strip (especially if it has surge protection) can interfere with network communication. Try it and see what happens.

POWERLINE NETWORKING FROM THE DECK OR VERANDA

The Annoyance:

My friends who have wireless networks brag that they can take their laptops outdoors in nice weather and stay on the network (giving them Internet access). If I string an extension cord to my deck (which has no power outlet), can I plug my adapter into it?

The Fix:

Of course you canan extension cord is a direct line to a wall outlet. And unlike your wireless-enabled friends, you won't have to reposition your chair several times to find the network signal.

INSTALLATION SOFTWARE IS A MUST

The Annoyance:

In addition to installing drivers for my powerline adapters, I have to install a whole software program. Why?

The Fix:

Security. The software that comes with a powerline adapter includes the security program that makes sure your network communication can't be hacked by an outsider. The software enables the powerline device to apply security without requiring you to go through a complicated configuration process.

DES SECURITY

Powerline network devices that adhere to the HomePlug standard use DES security to make sure nobody can grab your network communications. DES stands for Data Encryption Standard, and it's so strong that the United States Department of Defense uses it. With DES security, data that's moving between computers is encrypted.

DES provides a minimum of 72 quadrillion (that's 15 zeros after the 72) possible encryption keys that your powerline device can use. For each data packet that's exchanged across the network, the device chooses one key at random from this enormous number of possible keys. When the encrypted data is received, the receiving computer's powerline adapter takes care of finding the key and decrypting the data. Because of the strength of this type of security, it's almost impossible for anyone "eavesdropping" on the communication to read the data.

WHAT'S THE SECURITY RISK FOR POWERLINE NETWORKS?

The Annoyance:

I know that wireless networks have a reputation for being prone to security breaks, but my powerline network exists totally inside my house. None of the network data is floating around the air the way wireless transmissions can. Why do I have to worry about data communication security?

The Fix:

You're right when you say the risk of data being grabbed as it travels between one computer and another on a powerline network isn't anywhere near as high as it is on a wireless network. However, your data isn't as enclosed in the safety of your electric wiring as you might think.

The gateway, or barrier, for your powerline network is the transformer that supplies electricity to your building. Anyone sharing that transformer is on "your side" of that gateway. That means anyone who plugs in a powerline computer on your side of the gateway gets to participate in your network (see "Change the Default Security Password"). For most single-family homes, this doesn't present the problem that occupants of multidwelling buildings face. However, even a single-family dwelling can share a transformer with the building next door. Install the security software that came with your powerline adapter to avoid any problems.

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Warning: Any discussion of security for data moving between networked computers represents only a small part of the security problem. Beyond data packets, you have to worry about viruses, worms, and interlopers who get to your data over the Internet. Security is probably the biggest annoyance in computing! Chapter 7 has plenty of information about securing your computers and your network.

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SECURITY PASSWORDS MUST MATCH

The Annoyance:

All three computers on our powerline network seem to be working properly. The link lights are on, the TCP/IP settings are right, and all three can get to the Internet. But one computer can't participate in the network. It can't access the other two computers, and the other two computers can't get to its files. This is really annoying. In fact, it's driving me crazy!

The Fix:

I'll bet that the security password for the isolated computer doesn't match the passwords you installed on the other two computers. All the passwords must be the same. Anyone (well, in this case, anything) that doesn't know the password can't play!

CHANGE THE DEFAULT SECURITY PASSWORD

The Annoyance:

It takes time to go to every computer on my powerline network and change the password. The default password is already the same on every computer, and I don't have to worry about an unmatched password. Why can't I just leave well enough alone?

The Fix:

Because leaving it alone isn't "well enough." The same default password comes with every adapter sold by the manufacturer of your adapters. Anyone with the same adapter can plug into the wires connected to your transformer and get to all the files on your network.

Generally, if you use computers, you just have to get into "paranoia" mode because security is such an issue in the computer world. Changing a bunch of passwords takes only a few minutes, and it secures your network communications, so just do it!

MIXING POWERLINE WITH OTHER NETWORK TOPOLOGIES

The Annoyance:

I loved being able to create a network on our second floor without stringing cable through the walls, but in our family room we have a router and two computers with Ethernet adapters. The computers are plugged into the router. I have empty Ethernet ports on the router, but no more Ethernet-enabled computers. How do I add the powerline network to the router?

The Fix:

You need a powerline-to-Ethernet bridge. This nifty device, available for about $50 from all manufacturers of network devices, has two types of connections: powerline and Ethernet. Plug the powerline side of the bridge into an electrical outlet near the router (ta-da! the bridge joins the network), and run Ethernet cable between the Ethernet port and the router (ta-da! the network joins the router). Is this easy, or what?