Swap phone lines for ethernet

My house is wired with phone sockets in many rooms, none of which we use since we have a wireless phone. Could I just change out the telephone cabling and sockets for Cat 6a (assuming the conduit is big enough) and could I then just plug my modem into the nearest socket for a house wide internet access and network? I guess lots of houses have redundant telephone lines these days, has anyone done something similar or am I completely off track in my thinking?

Hum. Not quite sure what you are asking but a coupe of things to note.

In my experience many times the phone socket box is smaller than a standard single gang face plate. If yours are single gang thats great

The cable in for the phone is not ethernet so your next question is can you pull that wire out (with the cat 6 connected to it so the cat6 replaces the old wire

But. As a minimum you really want two (or more) runs of ethernet in there, you will always want more! But two is the minimum

Where is the ethernet going? Lets assume you have 5 sockets in the house and that you are able to pull the ethernet for all of them, that ethernet has to make its way to a switch, which in turn has to make its way to the router. Can you achieve this?

If you have all those bases covered, fill your boots.

But use Cat5e, it smaller does the same job and you will have a better chance because of it.

Oh, and use Excel RJ45 sockets.

Strip out all the unwanted surplus phone ext wires & sockets to reduce noise & improve ADSL performance (that alone is the biggest bang for buck) The phone cable wiring should be standard twisted pair phone specification. If in doubt strip it out & replace. Nothing more will improve your phone line side broadband performance.

If the phone wiring is redundant, you might as well strip it out. If you can use it to pull Ethernet cable through the same conduit, great. I agree that you’ll have a better chance of success with more flexible Cat5e, and it should still work fine. If you have the chance to pull 2 or more cables, great, but one, with a switch on the end to give you as many ports as you need, will be all you need to get things working.

One point that is mentioned in the above pieces of advice, but you might miss, is that there is another significant difference between phone lines and ethernet. With phone lines you just join the conductors together so that all of the phone lines can carry the signals.

But with ethernet you have to plug one end of each cable into an ethernet switch. That can be one switch or it can also be a number of switches that are themselves joined by ethernet. The likelihood is that some of the existing phone line runs will not end up in a place that is convenient for a switch, which incidentally also needs mains power.



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Why as a minimum? Yes, more may be useful, depending on what is wanted with the network now or in the future, but one cable is infinitely better than none!

To answer the OP, fantastic if the cable routing allows you to replace the telephone cables and sockets with ethernet - if in conduit or hanging loose without too many tight angles you might be able to pull Ethernet cable through tied to the phone cable (tue securely, in the least bulging way, and with any cable ends taped up so they can’t snag on anything. You’ll then need a switch (router) at the point where they all meet up, with that wired to your modem.

Appreciate the replies so far.

Phone sockets all have single gang face plates so all good there and all but one has a power outlet next to it so will keep that in mind.

Point noted re. ease of working with Cat5e. I had thought about 6a for less transmission loss as it would reach 3 floors (possibly 4) but if 5e is all that is required, it’s good to keep in mind. I guess I would let the sparkie decide based on how big a job it might be i.e. maybe future proof if feasible with 6a but if it over complicates things, stick with 5e. All wiring is in conduit so that should help.

No ADSL, we have fibre for phone and internet. A wireless phone plugs straight into the modem so the existing telephone cable runs are totally redundant. A wireless router (airport express) also plugs into the modem for household wifi network (with satellite extensions). I guess technically it’s a combined modem/router.

The original telephone socket where it comes into the house is right by the modem so if that socket (which no longer has an incoming phone line) was replaced with an RJ45 and in turn connected to the other sockets via ethernet cable, I was thinking I would then just connect the modem/router (there are 2 more spare ports) to that socket to feed the entire network?

I had assumed I could then connect to any of the connection points on any floor, for fast internet (we have 700mbps but obviously don’t get close to that through wifi), NAS sharing, connecting multimedia devices etc. either directly or via a hub of some sort if more connections are required. Even to eliminate wifi dead spots by setting up each floor with its own wifi network (house is reinforced concrete construction and wifi penetration isn’t great).

I had also assumed I could do all of this with one run and daisy chain between sockets ?

From that it sounds as if at present all the individual cables to different rooms (I’m assuming that is how the phone wires run) join together behind or in the socket by your router/modem, or perhaps daisy-chain. Ethernet cables can’t do that, and they can’t daisy-chain - they all need to run direct into a switch, then one cable from that to the modem/router, unless the latter has enough sockets for all the cables to connect to it. If my understanding of your layout is correct means having multiple RJ45 sockets to bring them out, or have the cables themselves coming out of the wall. You can get double multiple-RJ45 faceplates. I have mine as cables coming out of the wall (the hole well sealed with silicone), but that is at the end of a high shelf on the landing, where all but invisible.

Ethernet cables can’t do that, and they can’t daisy-chain

Ah, that could be the showstopper right there ! Pulling one cable through is one thing, pulling 3 or 4 is another entirely…

Time for a re-think or at least a professional survey to see what might be possible without opening up walls.

Many thanks…

I have three switches around the house, and the data going between my NAS and streamer has to go through all of them. It works perfectly, as I would expect it to. Or do we have a different understanding of what daisy chaining switches means?

OK, whatever it is a good idea to get rid of unused phone extensions, the cable & the open (unused) sockets add the potential for noise & lower performance.
I seen improvements a few times, I used to have extensions all over the house & two phone lines; needed for working from home, phone fax & telex (remember those?) & cordless phones had not been invented. The phone company came in to move the entry point & ripped it all out. Huge improvement, silent line phone calls, better BB line speed & no drop outs.

Exactly as Chris says. I have six switches in my house, all daisy-chained in a multi-branch sense, with streamers all over the house. I plug whatever in to the nearest one and it all just works.


If I was doing 3 floors I’d use a switch per floor if they could be located out the way somewhere.

Less copper to run up & down.

Err, of course you can daisy chain Ethernet links…
Standard phone wiring is pretty similar to Cat5… it all started as the same thing… it all uses similar impedance twisted pair. However in the UK most professionally installed phone cabling is 6 wire (3 pair) where as Ethernet is 8 wire (4 pair).
If you know what you are doing you can use phone cabling to wire up a 100 Mbps duplex Ethernet link… so it won’t support 1Gbps, and won’t be compliant to 100 metres, but should work.
You should keep your actual telephony and xDSL cabling physically separate from your Ethernet wiring… otherwise you will get bad cross talk and impact both xDSL and Ethernet performance.

So not a dead duck yet it seems…

If I was doing 3 floors I’d use a switch per floor if they could be located out the way somewhere.

Making sense to me now…

You should keep your actual telephony and xDSL cabling physically separate from your Ethernet wiring… otherwise you will get bad cross talk and impact both xDSL and Ethernet performance.

I don’t use DSL or the telephony cable, which I why I thought of replacing it with ethernet cable - a little more work but less compromise.

My first thoughts were physically connecting (punching down) two ends of cable at one socket, so I can connect a device at that point but the cabling continues onwards to another socket and so on - that is what I meant by daisy chaining. I am hearing that is not possible but I could install double sockets, each with its own cable, one from the floor below and the other to the floor above. I would use a switch at each floor and simply connect it to one socket and then straight back to the other socket- so daisy chaining the switches rather than the cable itself.

Does that sound about right ?

Yes, just connect via a switch on each floor, and use patch cables to connect individual devices to those switches. Simple.

Perfect ! All I need now is to make sure there is space in the conduit to pull the ethernet through !

Using a switch at each node to effectively daisychain is another matter, but very different from simply bonding the wires at the back of the RJ45 socket, but:

If that is the case, I take back what I said. In the days of coaxial networks (10Base2, e.g. “thin ethernet”), daisychaining was the norm, with the cable “teeing off” at each computer, but I thought that wasn’t possible with 100BaseT or 1000BaseT. Apologies for my misleading earlier post.

It depends what you mean by daisy chaining… if you simply mean joining Ethernet segments together to form a single segment (via connecting patch leads)… then no problem which is what I refer to
If you are sharing many hosts via a hub ( as opposed to a switch), then effectively combining on a single collusion domain… then it is possible but half duplex operation is employed and CSMA/CD is employed to manage data collisions on the segment (similar to Wifi). Half duplex operation is less performant than full duplex and the difference is proportional to the number of active hosts on the segment.

“Perfect ! All I need now is to make sure there is space in the conduit to pull the ethernet through !”

Also run a sturdy cord through, leave it there, if you need to pull any more cables you can use the cord as a pull cord.