We were pretty hard on Intellon and networking product manufacturers for advertising these products as 85Mbps and only delivering an average of 10Mbps. What do you think?

Another significant issue with homeplug and all powerline technologies that is not getting enough serious discussion (and that is especially pertinent to the broadband IPTV providers out there), is the fact that many homes in a neighborhood are on the same physical wire - and so would share the same homeplug network. One house is not isolated from another. It is much like being on an old ethernet hub.

Every home on my street that resides behind the same electrical distribution (aka isolation) transformer will be receiving the homeplug signals in their home up to the range of the signal - approximately 250m to 900m (I believe). So all homes in a given neighborhood that have homeplug AV, (200Mbs raw, 70-100Mbs real usable throughput) will *share* the purported 70-100Mbs of throughput (we'll assume their claims are true for the purpose of this dicussion though your test on the 85Mbs technology would cast some doubt on those claims).

If five homes have signed up for the IPTV service and use Homeplug AV, each will have a theoretical best throughput budget of 14-20Mbs. Assuming again that there is a solid 70-100Mbs available and that is highly doubtful. Assuming too a very clever QOS that prevents one neighbor from hogging all the bandwidth.

To block the signals between homes would require a filter to be installed on the incoming electrical feed by a journeyman electrician. Even if service providers would take this step (not very likely due to liability issues) it would block future BPL services from the electrical utility and might not be allowed.

The whole homeplug solution is not what many would have us think it is. There are significant problems in moving very high speed network data in a very nasty and ever changing environment.

Unfortunately, while the physical signaling rate for networking products is a constant (85Mbps for these HomePlug Turbo adapters, 54Mbps for 802.11a/g, etc.) data throughput varies widely from product to product and situation to situation. The result is that is hard to advertise a throughput rate. If you advertise a "typical throughput" data rate that is too low, the competition will eat you up when they continue to promote their lofty "maximum data rate" (physical signaling rate). If you advertise it too high you'll get all the same complaints about products not being as fast as advertised.

The review did not really help me compare this technology with wireless. Too much time spent on the advertised speeds vs real world speed issue and not enough info about pros and cons particlarly vs wireless solutions.

All the adverised claims about throughput for wireless devices are fiction particuarly in real world homes. Much as it should be noted if comes across as the main point of this review. If your campaigning on this issue include it in all your reviews not just this homplug one.

Also if your using the test locations used for wireless you had better give us a bit more information about the state of your electrical system. We would all understand if you said the wireless signal had to go through x brick walls and y floors. I have no idea if you regard your house wiring as good, bad or indifferent. If the test locations are on the same cables etc.

First, let me confess my ignorance of the tool you used to site performance.

Without knowing packet size bandwidth is hard to predict. For example, I have a 48Mbps wifi link that when I test using max packet size my bandwidth is 7.7Mbps @ 658 PPS. Using the same link with min packet size the numbers are .47Mbps @ 918 PPS.

As to the difference in performance based on location I would suspect that you may be on different phases and that there may be 'stuff' plugged into the electrical that is not powerline friendly.

And to the poster that was worried about crossing transformer windings I can only tell you it is harder than you think. I worked for an in-building plc company that exceeded the homeplug standard transmit levels and it did not cross.

Does anyone know if having a regular Homeplug 1.0 adapter on the powerline network will slow down all Homeplug Turbo adapters on the network?

In other words, do Homeplug Turbo adapters drop down to the slowest adapter on the network? Or can it communicate to at turbo speeds with Turbo adapters and 1.0 speeds with older adapters at the same time?

I already have 3 Homeplug 1.0 adapters. I'm thinking of replacing two of them (I might replace the other one later when money permits) with the new Turbo adapters. Will leaving one Homeplug 1.0 adapter on the network reduce everything back down to 1.0 speeds?

Here's the reply direct from Intellon:

Thanks. Unfortunately, I ended up buying a new Netgear HDX101 adapter with the DS2 chipset because TigerDirect was advertising the HDXB101 kit (consisting of 2 adatpers) for $109.99. I figured for that price, I might as well test it out! I said unfortunately because I ended up getting the single adapter and not the kit (it was a pricing or print mistake). I ended up just keeping it because I didn't want to bother with packing it up and shipping it back for RMA.

Now that I've read a little bit more about the HDX101 and your excellent Corinex AV200 review (which uses the same DS2 chipset) I am now having buyer's remorse for other reasons than getting the wrong product.

I didn't know that the DS2 standard didn't coexist well with Homeplug 1.0. I knew that it couldn't interoperate with them but I was under the impression that it could coexist. Now I wish I had waited for Homeplug AV or saved some money and get Homeplug Turbo. I think that the DS2 product will probably work well in my environment but it would have been nicer to be able to leave my current Homeplug 1.0 network in place. Oh well, live and learn...

Has anybody actually tried using a powerstrip (non-surge protector type) with these adapters? I'm thinking that it should work without any problems but that Netgear is just being safe when they advise to plug them directly into the wall socket. The only problem is that these units are so big and blocky they could block out the socket for other plugs.

Here's the reply direct from Intellon:

My HDX101's worked great on a power strip, as have all PLC devices I have tested.

That's great to hear. That will make setting things up easier for me (I have some furniture blocking my wall socket in a way that would have required me to move things around if I had to stick that powerline adapter directly in the socket).

Now, I just have to order another adapter to go along with the adapter I have now.

BTW, I read some comments that these things get really hot. Has this been the case for you?

Really hot? They get quite warm but are not a hazard to touch.

FYI - I ran a test between two oof these units connected on a power strip as was able to achieve wire speed.

It's the surge protection circuitry that blocks the PLC signal, so using an ordinary power strip will have no effect.

Unfortunately you had to find out the hard way that DS2 and their customers are basically lying about their ability to coexist with HomePlug devices.

I was under the impression that DS2 and HomePlug could co-exist on the same network, though they would both suffer performance issues.

That's what they claim. I suppose if the network traffic on each network was extremely light (or one was idle while the other was busy) they might work together. We tested quite a few of these and coexistance is a myth from what we saw.

See
http://www.tomsnetworking.com/2006 [...] age10.html

Sorry, what I meant was that Netgear is claiming coexistance. From Netgear's website on the DS2 based HDXB101: Powerline friendly—coexists with NETGEAR’s Wall-Plugged and HomePlug® compatible products

Well, I now have 4 of these units plugged into my house and I'm a little disappointed in the performance. I'm getting about the same performance as my WirelessG network. I was hoping for better.

My 4 units are located as follows:

Basement - with my main router and DSL modem
Living Room (middle floor) - with my Tivos
Upstairs Bedroom
Upstairs Office

According to Netgear's utility, I am getting these results:

[code:1:54d3ff114d]
Location Tx (Mbps) Rx (Mbps)

Upstairs Office (Local) 200 200
LivingRoom 68 61
Basement 78 80
Bedroom (Upstairs) 77 91
[/code:1:54d3ff114d]

But actual throughput from iperf indicates I am only getting about 12 Mb/s (1.5 MB/s). Other tests seem to confirm this. This is about the same as I was getting from my WirelessG network. I was hoping for at least twice the speed of WirelessG because I wanted better performance from my NAS unit located in my basement.

What settings did you use in iperf?

I just used the standard default settings from iperf. For the server, I just use:

iperf.exe -s -D

to start it up. And for the client, I just use:

iperf.exe -c 192.168.0.2

I heard that powerline has low latency and that if we adjust the TCP window size, we should get better performance, but I'm somewhat wary about changing that on my network.