Using data and phone in one single wire

Question

Using data and phone in one single wire

nickel052 (Instructor)

(OP)

4 Feb 14 23:05

I have a desktop computer hooked to my network through a wired connection. My router is in my basement by the panel. There was a phone plug behind the computer that I turned into an ethernet plug since I never used phone there. The wire was not part of the main phone loop wire for the house; it went directly to the basement panel. I disconnected it from the phone panel and put an RJ45 data plug on it to plug it into the router. My house was built in 2000 and was not wired with cat5 (expect the main house loop). The individual wires that go to the panel are cat3 wire with 3 twisted pairs (6 wires in total). For the cat3 wire for the computer, I am only using 4 wires (2 twisted pairs) and it works flawlessly at 100 mbps. There is one twisted pair remaining unused in the wire. I have decided that I may actually need a phone there and may need to use that phone plug. I was hoping to hear some feedback on whether it is ok or not to use the remaining twisted pair in the cat3 wire as phone. To clarify, 4 wires would continue to be used for the computer's data connection and the remaining 2 would be hooked up to the home phone panel. I know it is not the best idea and I may encounter some interference but I wanted to hear some more opinions.

Thanks a lot.

misseditbythatmuch (TechnicalUser) · Answer 1 · 2014-02-05 02:18:09

This kind of improvised cabling is done with good results fairly often. Fair to say that this breaks most of the rules for structured wiring and leaves a mess for the next person who needs to service the cabling. However, in most single family sized homes, the homerun cable runs are short enough that cat3, run properly, will service 10/100 Ethernet with tolerable packet failure. The added phone line pair use will degrade your network performance, but little enough that a desktop computer will generally not exhibit adverse performance to the casual eye. Your biggest challenges will come when the phone is ringing (ac signal) at the same time you stream high quality video or similar high content data streams. The degree of challenge is also the result of the NIC and router and whether the router has QoS support. Your voice path will work fine and you will not notice any quality issues (assuming a POTS line). I do suggest that you make sure your phone demarc is properly lightening protected, because an unprotected shot will probably take out your phone and network hardware as that cat3 cable has a low arc threshold for crossover voltages.

nickel052 (Instructor) · Answer 2 · 2014-02-06 13:45:23

Hi missedit. I thought it would be ok to do so. The cat3 runs are not long at all. And I have actually yet to have any packet failure luckily. The router does have QoS support as well. I noticed even before when I had wireless N adapters on my computers, when the phone rang, the cordless phones took out all the wifi-N signals; but the wireless-g computers were fine. And yes the phone line is properly protected and so is the router. I will probably give this a shot this weekend sometime. Thanks a lot for the feedback.

Yorkie9 (TechnicalUser) · Answer 3 · 2014-02-08 03:55:56

sounds like you want something like a RJ45 cable economiser?

they come in three flavours,

data- data

data - voice

Voice - voice

just look on the web for whichever type you want, they are in pairs (one at each end)

1a22ip (TechnicalUser) · Answer 4 · 2014-02-08 10:52:57

I have successfully "split" off the brown pair and used it to connect telephones. I wire the Blue-Orange-Green as standard. I then take the brown pair to a separate Port on a 2 port jack or tap a second single port jack wiring the Brown pair to the blue pair terminals. On the other end of the cable I wire the Blue-Orange-Green as standard and route the brown to the Tip and Ring for the telephone. Been doing it for years. Please note the above will NOT work if your data connections are using POE. Power over Ethernet.

Hope this makes sense
ED

1a2 to ip I seen it all

nickel052 (Instructor) · Answer 5 · 2014-03-03 19:56:38

Sorry for the late reply. Been busy with school. Anyways I did try this and it worked (and continues to work) perfectly fine. No problems at all, no interruptions, no noticeably reduced network speeds. Its perfect. Yorkie9 I actually did not need an economizer. I just used the female RJ45 and RJ11 connectors and put them right on the wires inside the wall with a punch tool. Then I mounted the connectors on a faceplate and screwed it all back into the wall. As for the end in the basement panel, I used the green pair for phone and screwed the two wires right into the phone box. The remaining two pairs (orange and blue) I used for internet and put an RJ45 male connector on it and used only pins 1,2,3,6. I also made an error in my last post. The cat 3 wires in my house are in fact untwisted pair, although this has not hindered the performance of the internet. 1a22ip, no POE connections in the house, strictly data. I think my cat3 wire may actually be cheaper than the standard. Only a couple of the cat3 runs in my house have 3 pairs. The rest of the cat3 runs have 2 pairs leaving only 4 wires to work with (which means I would have to pick between wired internet and phone if I ever have a computer at that outlet).
Thanks all for the help!

misseditbythatmuch (TechnicalUser) · Answer 6 · 2014-03-03 22:02:44

While I am not a fan of these, I have used them in a pinch a couple of times with satisfactory results: NETGEAR Powerline 200Mbps Nano Adapter - Starter Kit (XAVB2101)
Just a thought if you are fully out of pairs and do not want exposed cables festooned about your rooms.

jrgood0852 (TechnicalUser) · Answer 7 · 2014-03-04 08:06:20

If the cables are cat 3, I am shocked that you are getting 100 meg rather than 10 meg, but must be goor twists, short runs and near perfect terminations. Good for you.

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Using data and phone in one single wire