power over ethernet

Sorry ... why do you feel PoE is bad?

I think he means Ethernet over power ie PLT, which would be daft if a cable could be run easily instead.

David Hendon posted:

I think he means Ethernet over power ie PLT, which would be daft if a cable could be run easily instead.

That makes more sense to object to!

POE is fine.... EOP isnt. 

Whats wrong with Ethernet through a house mains? Recently installed a network and my NDX and NAS link to the BTrouter via a gigabit switch and this network. Got me worried now!

Loon at what happens. You are adding a shed load of digital noise to the mains

now go look at your lovely expensive Naim power supplies. All that filtering... To remove noise from the mains. Why add it in the first place? Why degrade your supercap to hicap performance? 

Jon  - it was added as a means to connect a PC,  a Router and my hifi which reside in three separate rooms and over two levels of the house. That arrangement can't change (geography and WAF reasons). The NAS and NDX are connected via a switch to each other and the switch is also connected via mains Ethernet to the router and PC for updates and internet radio. I honestly can't hear any sound degradation since installation. I could always unplug the Ethernet cable from the mains to the switch box when listening off the NAS I suppose...

You could try connecting a wifi extender (or an airport express) to the switch, and connecting to the router via wifi - assuming that the wifi signal is strong enough. This seems to be the best way in situations where a fully wired nrtwork is impractical. 

Power over Ethernet is fine as long as you have the right network switch equipment.. and sufficient powersupply on your switch to manage your PoE load.

Perhaps you are confusing with Ethernet over Powerline which is the Devil incarnate 

Hi

Not much experience in these matters but could you clarify what the difference is between Power over Ethernet and Ethernet over powerline  is ? Also if the Naim power supplies are designed to filter noise out then wouldn't they filter any additional noise ? I'm a  total dummy on this issue, however, hardwiring various Hifi equipment for me is not very practical at the moment hence the question

Power over Ethernet sends power down the Ethernet cable. Ethernet over mains sends Ethernet signals through the mains wires. It's as simple as that. 

Simon-in-Suffolk posted:

...Ethernet over Powerline which is the Devil incarnate 

Too true, when I replaced the Powerline adapters with wired Ethernet I not only got 96KHZ streaming working but there was a noticeable improvement in SQ even on the Mu-so.

Also, this may be entirely coincidental but we were having problems with the remotes for both our cars (we had to get right next to the car to make it work).  We had replaced batteries and dealers had checked them but no fault found and no change.  The problem only seemed to happen in our drive.  We suddenly noticed that the remotes were working from a distance again after the Powerline adapters had been removed and have had no problems since.

Hungryhalibut posted:

Power over Ethernet sends power down the Ethernet cable. Ethernet over mains sends Ethernet signals through the mains wires. It's as simple as that. 

To some extent, Ethernet over Powerline doesn't actually send the Ethernet signals down the mains, but uses its own proprietary protocols and RF modulation techniques to act as a kind of Ethernet bridge... 

Simon

interesting -- i am glad i didnt approve this 'ethernet over power' -- just the neurosis alone would have killed me :-(

enjoy

ken

Simon-in-Suffolk posted:

Hungryhalibut posted:

Power over Ethernet sends power down the Ethernet cable. Ethernet over mains sends Ethernet signals through the mains wires. It's as simple as that. 

To some extent, Ethernet over Powerline doesn't actually send the Ethernet signals down the mains, but uses its own proprietary protocols and RF modulation techniques to act as a kind of Ethernet bridge... 

Simon

 

So, say I had a Powerline adaptor in the sitting room and another in the bedroom. I plug my laptop into the first, and my printer into the second. How does the signal get from one to the other if it's not down the mains wire? Am I being dim?

What happens is that the power line adapters send very high frequency signals, more or less like radio signals, over the mains wire. The Ethernet is modulated or coded onto the radio signal. So what goes in might be nice clean low jitter Ethernet and what comes out is Ethernet but probably full of all sorts of artefacts. The use of vhf carriers is why Peter had interference with his car remote opening. I'm sure that isn't a coincidence.

bedt

David

So, the Powerline is sending radio signals, onto which the Ethernet signals hitch a ride. So by definition,the mains is being filled with RFI, which then buggers up the sound. Is that right?

Hungryhalibut posted:

So, the Powerline is sending radio signals, onto which the Ethernet signals hitch a ride. So by definition,the mains is being filled with RFI, which then buggers up the sound. Is that right?

More or less.  The poweline adapters convert the Ethernet to their own signalling protocol and back again at the destination plug.  They can send data at 300 mbps + so they will be sending RF signals at 300MHZ+ over your mains wiring which not only makes it very noisy but also turns it into a gigantic RF radio wave transmitter.

HH, Ethernet is a set of low level protocols... Ethernet over Mains does not use these protocols, it uses its own protocols to send the data over the mains.. You could argue its semantics... But it's the same as saying wifi is not Ethernet either.. I don't believe Ethernet over Powerline simply encapsulate Ethernet..

But yes the Powerline adapter devices use a wide band RF modulation technique where there are hundreds if not thousands of small RF carriers which are each phase modulated. This modulation is used to encode the data. It is these hundreds of RF carriers  that when transmitted and conducted into the mains wiring cause the mains wiring to produce not in considerable near field EM emissions and in some cases even far field radiation...  The frequencies bandwidth used starts at 3 MHz approx and rises upto near 200 MmHz or higher depending on design. Because they are effectively radio transmitters protected frequencies are notched out..so as to minimise  radio interference to protected bandwidth users.

Simon

Thanks Simon. It sounds highly dubious and best avoided. 

I suspect, as with many things, the truth is rather more prosaic. 

In some situations the results will be dire as with Peter's car keys and in others no discernable adverse effects will be noticed. 

I currently have 4 in my home connecting the router, Muso, UnitiServe and streamer.

My experience is that a cheap SMPS (like those powering a consumer switch or a NAS) plugged into the same sockets as my Naim amps had a significant adverse effect on SQ that I haven't had with powerline adapters.

They aren't particularly expensive, so I'd say if a wired connection isn't practical in your situation, try them - you might be pleasantly surprised.

Olly

Very interesting. I have been a little dissatisfied by the slightly distorted sound of vocals on my 272. Reading this I unplugged my Ethernet over power devices and immediately it seems much better. More investigating required as I am demoing speakers at the moment so not too familiar with the sound but I think I may be off to buy a wireless extender tomorrow!

Oh, my, i am pleased i didnt agree to this EoP business for our security system 

seems to be potentially bad news!

enjoy

ken

ken c posted:

Oh, my, i am pleased i didnt agree to this EoP business for our security system 

seems to be potentially bad news!

enjoy

ken

EoP is not a sensible solution for business.

Indeed I feel the technology is for desperate consumers who have no other way of getting a low spec data link  across thier house..and have tried all other avenues.. From a network data point of view it's not ideal and a compromise, and from an EMI point of view it's bad news, although later chipsets have tried to reduce damaging side effects when in stand by and not transferring data.

Simon