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Help ! Ethernet wiring signal loss

shermans
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Registered: 07-09-2007

Help ! Ethernet wiring signal loss

Can anyone help with an ethernet problem ?
I have WiFi installed in an old house with very thick walls.  Using VOIP on WiFi is not practical due to lack of performance.  Being in very remote country, the best I get on broadband is 512k if I am lucky which for most things is just about adequate, but not for WiFi and VOIP.
I should add that the house I am talking about is in France !
When the house was recently re-wired, the telephone circuit was installed with Cat5 wiring throughout - 8 sockets in total.  French telephone sockets have 8 connections, of which two are for the telephone of course.  I have therefore used another two to enable me to plug the WiFi router into any socket in the house, to avoid the thick stone walls (3 ft).  That works well (surprisingly) and there does not appear to be any signal loss at all, and does help with VOIP.
However, it is inconvenient to keep unplugging the router and moving around from room to room.
So I decided that it would be much better if I installed an ethernet using the four spare wires in the circuit.  But the result has been a total disaster and a waste of a whole day spent  on my knees with a multi-meter checking connections, but not being able to get the ethernet working.  Connect to a computer with a cable directly between router and computer, and the ethernet works fine.  Connect using the four spare wires, and nothing.
The wiring is basically a star or hub and spoke - all four circuits start in the middle and radiate out to the 8 sockets around the house.  There are in fact three spokes, with the longest being about 30 meters, with three sockets on it.  The other two hubs are much shorter - 7 meters max.  But even using just one hub and disconnecting the others, no luck.  I realise that with this sort of set-up, I can only connect one computer to the router at a time.
My conclusion is therefore reluctantly that there is too much signal loss in the French telephone sockets.  These are not neat little RJ11s.  No, French sockets are more like a nuclear power station.  Each connection has a spade terminal which is 7 mm across x 50 mm in length.
So ultimately my question is :  Are these massive spade terminals likely to be soaking up so much signal that the ethernet can no longer identify the signal ?
If that is the case, then I do not understand why these same spade terminals manage to carry the broadband signal without problems, but not the ethernet signal.
Before I go and spend hours replacing all the France Telecom sockets with RJ45s, can anyone confirm that these nuclear power stations terminals are the likely cause ?  I am attaching a photo of the nuclear power stations.
16 REPLIES
Superuser
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Re: Help ! Ethernet wiring signal loss

Quote from: shermans

My conclusion is therefore reluctantly that there is too much signal loss in the French telephone sockets.  These are not neat little RJ11s.  No, French sockets are more like a nuclear power station.  Each connection has a spade terminal which is 7 mm across x 50 mm in length.
Before I go and spend hours replacing all the France Telecom sockets with RJ45s, can anyone confirm that these nuclear power stations terminals are the likely cause ? 

From your description, it isn't very clear how you have wired the system?  Ethernet cabling is (essentially) point to point and has quite prescriptive wiring at the RJ45 ends to ensure that the 4 pairs are used and terminated correctly.  If, as I guess from your description, you have just used 4 wires rather than two pairs AND in a star configuration it is very unlikely to work?  How are you wiring from the 'nuclear power terminals' to the RJ45 you connect to the router?  Even if you re-terminate in RJ45 sockets you will need to get the pinout's correct for it to work though Undecided  I don't have the pin out diagram to hand at the Mo.  but can look it out if you need it.
Maurice

shermans
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Re: Help ! Ethernet wiring signal loss

Here is a diagram.  The green boxes are all the 'nuclear power stations'.  The wiring is not ideal, because there is one long run and two short ones.  However, the wiring went in before the ceilings went up, so I am stuck with what was installed.  But as the wires are there, it is a shame not to be able to put them to good use.
There are four pairs of wires running between each 'nuclear power station'.
1 and 3 =  telephone
5 and 6 = ADSL
2 and 4 = Ethernet Pair 1
7 and 8 = Ethernet Pair 2
The ethernet is connected as follows :
Pin 1 and Pin 2 = Pair 1
Pin 3 and Pin 6 = Pair 2
Hopefully that explains things.
I tested the pairs as follows : Each 'nuclear power station' plug can commit mechanical b*****y, in other words, each one can have another 'nuclear power station' plug plugged into its back to add another extension.  One of the tests which I did therefore was to take the wire from the modem RJ45 to the 'nuclear power station' and the wire from the 'nuclear power station' to the computer, and plug them into one-another, piggy back style, without plugging into the Cat5 wiring.  So in other words, I made one ethernet cable out of two cables, and plugged one end into the router and one into the computer, and all worked fine.  That proves my connecting cables are wired correctly with the right pairs.  But connecting them to the Cat5 wiring results always in failure.  I have carefully tested the integrity of the pin-out connections from the modem through the Cat5 wiring and to the computer with a multi-meter, and all checks out correctly, with no crossovers.  That is why I concluded that the 'nuclear poer stations' were absorbing too much signal.
But maybe there is something else wrong with the basic layout.  If you have any suggestions, I would appreciate it.
Community Veteran
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Re: Help ! Ethernet wiring signal loss

Maybe I'm being dumb, but I had one of those French connectors until very recently (a modem adapter) but chucked it away.
I'm sure it only had 6 contacts, not 8.............
And another thing. Ethernet connections are point-to-point between active (i.e. powered, electronic) devices. NO branching. NO multi-drop.
And finally, ADSL will hate the branches too, picks up loads of interference.
shermans
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Re: Help ! Ethernet wiring signal loss

You are both right and wrong about the French connectors.  The original design was just six contacts, but the modern version has squeezed a further two contacts onto the bar of the "T".  All new sockets have eight contacts now, but the plugs come in both varieties, either six or eight.
I am interested about what you say about branches and the drops, and presumably therefore that is why I cannot get it to work.  But from what you say, there must be a difference between ethernet signals and ADSL signals, because the branches definitely work with the ADSL.  The ADSL performance is bad anyway, so it may be that the branches just cannot make it any worse.  I get more or less the same statistics no matter where I install the router - even at the master socket, where I can disconnect all the other branches, the performance is the same.  We are in the depths of the countryside, about two kilometers from the exchange, on a 512 Kb line, which is the maximum available :
Line Rate - Upstream (Kbps): 156
Line Rate - Downstream (Kbps): 604
SNR Margin - Upstream (dB): 24.5
SNR Margin - Downstream (dB): 7.4
Attenuation - Upstream (dB): 33.0
Attenuation - Downstream (dB): 70.0
I know the attenuation is very high, but it is the same even at the master socket, so I imagine I can do nothing about it but complain - fat good that would do because France Telecom is state owned and just gives rise to the "gallic shrug" !  The worst impact on performance is the WiFi inside the house due to the monstrously thick walls.
So, in conclusion,. are you saying that I will not be abler to get an Ethernet working with the branches, even though ADSL does ?  If so, I will not waste any more time on it.
Thanks for your help.

Superuser
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Re: Help ! Ethernet wiring signal loss

Quote from: shermans
So, in conclusion,. are you saying that I will not be abler to get an Ethernet working with the branches, even though ADSL does ?  If so, I will not waste any more time on it.
Thanks for your help.

I think you have come to the correct conclusion Wink  The cabling requirements for telephony and Ethernet are significantly different, it is not just a matter of getting the correct pinout at each end.  It is possible to share the CAT5 cable between Ethernet and Telephony, BUT you have to be careful to follow the Ethernet cabling rules and piggy-back the telephony (ADSL) onto the correct pairs etc. 
I have such a system working in a few local offices with around 20 Ethernet ports each - but it can still be a pain when one port just will not work!  In the UK there are a number of 'gadgets' to help you get this working fairly quickly (and neatly)  but I do not know of any French equivalents.
Now I'm normally an optimist in getting odd solution to work, but this solution ..............................?
Maurice
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Re: Help ! Ethernet wiring signal loss

Quote from: shermans
  The ADSL performance is bad anyway, so it may be that the branches just cannot make it any worse. 

Well they will definitely make it worse, but it looks like you're on a fixed rate product anyway so they'll not affect the speed, just the reliability.
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Re: Help ! Ethernet wiring signal loss

Ethernet (Cat5e and definately Cat6) cable is specifically constructed with pairs twisted around each other, and then the four "pairs" twisted throughout the length of the cable.
This is to minimise (not eliminate) crossfeed and chatter between the pair components, and the pairs themselves.  When you're pumping a signal in duplex down a 100Mbit ethernet connection there is a lot of potential for opposing pairs to pick up an induced signal.
There is a pretty stringent standard that Cat5e and Cat6 cable has to be constructed to to be able to refer to itself as Cat5e or Cat6 for exactly this reason.
Unfortunately, the wiring that you're dealing with is likely nowhere near the standard that you will require to be able to use it as an ethernet cable.  You *may* be able to get away with signalling at 10Mbit simplex but I wouldn't hold me breath, unfortunately Sad
B.


shermans
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Re: Help ! Ethernet wiring signal loss

That, I think, is probably the problem.  The wires are more like old telephone / burglar alarm wires.  They are definitely not twisted around each other, but just run together in the outer white insulation.  So I have learnt something new.  A wasted day from a labour point of view, but not from knowledge !
Any suggestions as to anything to overcome the lack of twisted wires ?
I wonder why on earth then they supply 8 wires, when you only need two for telephone Huh
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Re: Help ! Ethernet wiring signal loss

Sounds as if Mains Networking is the way forward then.
No specific idea why so many pairs are run, however its something I always do so I have some spare if I need them later on.
A few years re-wiring extensions around a large factory site teaches you a few tricks to save time in future.
Superuser
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Re: Help ! Ethernet wiring signal loss

Quote from: shermans

Any suggestions as to anything to overcome the lack of twisted wires ?

Ethernet over mains?  Works well.
Quote
I wonder why on earth then they supply 8 wires, when you only need two for telephone Huh

Multiple telephone lines;  odd extension needs (secretary xfer?)  burglar alarms..........
M
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Re: Help ! Ethernet wiring signal loss

Quote from: shermans
I wonder why on earth then they supply 8 wires, when you only need two for telephone Huh

3 or 4 actually for internal wiring, depending on the type of system (and more for some complex PABX systems).
Standard UK domestic systems need 3 wires and are usually wired with 4 or 6 core cable. With most "modern" domestic handsets though you only need 2 wires.
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Re: Help ! Ethernet wiring signal loss

I know we are straying a little OT here, but you only need two wires for a UK Domestic system, so long as you use the right faceplate.
For most modern phones this is completely irrelevant, since they only use two anyway, and don't rely on a ringwire.
For an older phone, you can still use a single pair of cables, so long as you terminate it with a master socket which has the necessary capacitor for generating the ring signal.
Alternatively you could use a secondary socket without a capacitor built in to terminate the cable, and then use an ADSL filter between the handset and phone, since the filters already contain the necessary caps to generate the ring signal for an older phone.
The ringwire *can* be eliminated from every setup in the country, so long as attention is paid to the components terminating the extensions etc.

shermans
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Re: Help ! Ethernet wiring signal loss

Why didn't I think of mains network before ? Huh  Of course, there are things called Home-Plugs.  But will they achieve the same sort of performance as a convenional hard-wired Ethernet ?  Because the problem I have is that WiFi is not good enough for VOIP due to signal loss through the thick walls, whereas when I connect an Ethernet cable direct between the router and computer, VOIP works fine.
Superuser
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Re: Help ! Ethernet wiring signal loss

Take your pick?  14 / 85 /200 Mbps  e.g. Solwise
M