Saturday, August 23, 2008

Powerline Ethernet

802.11 WiFi is still the most common means of creating home networks for sharing an Internet connection or files locally. However, WiFi frequently runs into problems due to interference from other devices using the 2.4 GHz wireless spectrum. Also, due to the low power output of WiFi devices, it sometimes has problems with distance and intervening structures.

An alternative is powerline Ethernet. This uses your home's existing electrical wiring to extend Ethernet connections. Typically, it uses wall wart unit that plug into electrical sockets and which have an Ethernet port, working as Layer 2 devices.

I installed a powerline Ethernet system this morning at a client's home. He has three machines: a G4 Mac Mini, and Intel iMac, and a Dell PC. His Internet connection is a Comcast cable modem. A Linksys WRT-54G router is plugged into the modem to share the connection and secure his network from the Internet. The Mini is connected to the router via Ethernet, while the iMac and PC were connected via WiFi.

Unfortunately, the iMac's wireless connection has seriously degraded recently, probalby due to wireless interference from neighbors. We figured that a hard wired solution would be best.

After looking around online and reading reviews, I recommend a Linksys PLK200 kit. The system requirements specify Windows, but that's only to run a setup utility which isn't really required in a typical home environment. I brought along my old Compaq Presario laptop running XP but wound up leaving the default settings on the Linksys units.

Setup was pretty simple and the devices found each other quickly. They have built-in surge protection and for that reason Linksys recommends not plugging them into a surge protector. They are fairly blocky, so they'd take block more than one outlet on a surge protector anyway.

The Linksys kit includes two Ethernet patch cords but they are only about 3 or 4 feet long. I had a hunch this might be the case so I brought a couple of longer cords with me, one of which I needed to use. The iMac's network connection looks like this:

{Cable modem}-{Router}-{Powerline adapter 1}-{House wiring}-{PL adapter 2}-{iMac}

After installing the Linksys units I ran a couple of Internet speed tests from the iMac and saw that they were comparable with tests run from the G4 Mini connected directly to the router.

Powerline Ethernet isn't as common as WiFi but home and small office users who can't use WiFi, and who can't or don't want to run Ethernet should be aware of it as an option.


geekWithA.45 said...

We've heard a lot of good things with that in residential and small office environments, though I haven't played with it myself. In terms of security, I think it substantially less secure than a truly hardwired environment, and probably ought to be characterized as wifi, requiring at least minimal crypto. Are such options available?

Dave Markowitz said...

The Linksys utility offered some level of encryption but I didn't really look into it. In a single home I don't think it's necessary. If it is in a multidwelling unit, e.g., a hotel or apartment building I'd recommend it.

Tony79 said...

I would like to connect a linux-only unit to my network, and I am considering the PLK200. I'm not too network-savvy so I'm afraid that I won't be able to get it going on a non-windows pc.

Are you saying you've used it out of the box and it worked? Simply by connecting the router to one adapter and a computer to the other? I don't have a linksys router... do you think that may cause problems?

Dave Markowitz said...


It should just work by connecting the two PLK200s to your network. I didn't do any actual configuration on the pair that I installed.

Likewise, a non-Linksys router should not be a problem based on how I understand how the powerline Ethernet adapters works.