Ask Lazyweb: Networking via Power Lines?

[tfofurn]

It has finally dawned on me that all of my networkable devices but one are in the living room. That lone exception is my desk machine in the guest room. I've been contemplating hiring an electrician to fish Ethernet through the walls to connect the cable modem in the guest room to a switch in my living room. I tried bridging this wirelessly, but

Comments

[alynch]

All of the HomePlug stuff does act as a true bridge, so you can use it with switches, etc...

A word of caution: 99.9% of the HomePlug gear sucks balls. High error rates, buggy link-up, slow speeds, etc... Good for data transfer of less than 2mbit, ie nothing.

There are a few new generations of gear coming out, which I hear suck less.

[tfofurn]

Is HomePlug AV one of the new generations or one that still sucks? They're claiming 200Mbit. Under less-than-ideal circumstances, I'll assume I'd get 20Mbit, which is still damn good.

[alynch]

Realistically, after protocol overhead, expect a maximum theoretical of around 80Mbit.

Add a less-than-ideal electrical environment, and speeds drop off that quickly.

I've used HomePlug AV (Netgear's version, rated highly by CNET) in 3 environments, 2 apartments and a friends house (none of which were mine). Only one apartment worked well enough to stream HD. The other two... Well, lets just say that 802.11b would have been better. I ended up installing 802.11g bridging APs and using well-tuned directional antennas.

And yeah, in each "bad" environment, I checked for the wiring layout in the panel, which as patrickwonders notes below, can be a bit of an issue.

I chalk it up to older wiring.

[tfofurn]

Hmph. My place is only twenty years old, so I wouldn't expect the wiring to be terrible. I don't actually plan to use it for high-bandwidth streaming. I'd be plenty happy with 20 Mbit, which is about what I get with my 802.11g now.

I'm starting to think I should start by moving the cable modem downstairs, and if that works, connect the upstairs machine with a USB 802.11 adapter.

[patrickwonders]

One other thing to consider, I suspect that it if it's sending data over the powerlines you will run into the same problem that X-10 users have.... Your house probably gets 3-phase from the street and breaks it into 2-phases for one side of the breaker box and 2-phases for the other side of the breaker box. Many folks have a terrible time getting a signal from one side of the breaker box to the other. It basically has to go out to the nearest telephone pole transformer and come back.

You can have an electrician put a special bridging breaker in if you've got enough space on both halves of your power box. Or, if you've got a 3-phase appliance like an electric dryer or electric range, you might be able to get away with a cheaper bridge that plugs in to that outlet and then gets your appliance plugged into it.

Something to consider if the places you want to network are on different sides of the breaker box.

[tfofurn]

Excellent point. I'll have to run around with my X10 stuff to see if I'll have such phasing issues with the desired outlets. My impression now is no, but I'd much rather find that out before plunking down $100 per module for HomePlug.