How can I get phone and DSL to a 2nd building?

Posted on 2011-02-10
Last Modified: 2012-05-11
I have Centurylink DSL & Phone service.  I have a DSL modem in my office in my house which I connect a single computer to.

I have a separate building which has a single CAT5E cable run underground to it.  Is it possible for me to use this cable to pipe both my internet connection and a regular phone line to this building?

If so please explain how I would go about setting this all up.

I do not want to do a wireless connection, I want to use the CAT5E cable if possible.
Question by:redrider02

Expert Comment

by:Greg Jacknow
ID: 34864284
It is really easy to run _either_ the phone or data over a single Cat5 line.

And as the Data nor phone do not use all the pairs in a CAT5 cable you can do a hack like this one:

Or you could just run data over there and use some VOIP phone service or skype.
LVL 32

Accepted Solution

aleghart earned 500 total points
ID: 34864346
Cat5 (4-pairs) can be split into the following:

2x FastEthernet (using two pairs each)
1x FastEthernet (using two pairs) plus 2x phone lines (using one pair each)

Splitting a network jack is not often recommended, as you're running different signals along the same cable.  There is a possiblity of interference between the connection, but in real-world experience, it does work in many cases.

You'll need to do the wiring by hand.  There are a couple of RJ45 adapter that some people recommend without having used them.  One is a splitter that gives 2x FastEthernet...but you can't use the second jack for a phone line.   The other is a pair splitter that give you 4 pairs broken out for 4x phone can re-combine the pairs for a network connection.

Punch down 1-2-3-6 to 1-2-3-6
Punch down 4-5 to 4-5
Punch down 7-8 to 6-3

Your phone connections should look like: Bl-R-G-Y in positions 3-4-5-6 of the finished RJ45 jack.

Hope that helps.

Since this is running to another building, did you already take care of grounding requirements?  Stray voltage can move from one building to the other over that cable, causing damage to person and property.  There should be a large gauge grounding wire bonding the electrical panels together.
LVL 32

Expert Comment

ID: 34864393
Soldering wires like this is completely unnecessary, and dangerous.  With those Leviton RJ45 jacks, you can pop the cover off, pull the wires, strip the sheath back another 3-4 inches, clip the bend ends off clean, then re-terminate all the wires into two new jack.  Either 2x RJ45 or RJ45+RJ11.

Lke I said...people who haven't done this in the real world will give you weird advice.

You can get "tool-less" jacks that include a tiny plastic pusher, or buy your own punchdown tool.  If you ever have to do wiring like this, a punchdown tool is worth the price, as you can work on other phone and netowork wiring in residential or commercial panels.
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Expert Comment

ID: 34864441
That instructables hack sounds like a really great way to destroy your only CAT5 connection between the two buildings...

While this is theoretically possible, it's unlikely that you'll get 1000 base T speeds on your network if you disassemble that much of your sheilding - Depending on the distance between the two buildings there's a good chance of reducing it to 10 base T or killing it altogether, especially without a proper punchdown tool, and given the amount of current used by PSTN lines.

The article itself says the guy didn't test for crosstalk - If you're going to try this, at least do a dry run using new cable and test for continuity and signal quality - I suspect you will be dissapointed.

Do yourself a favour and use the CAT5 for Data, and get the telco to extend the phone line to a separate demark in your second building.

I know it's not the answer you want, and a bit more costly, but you shouldn't compromise on infrastructure - If it's done right it only needs to be done once.

Author Comment

ID: 34864795
Right now the cat5 cable is not hooked up at either end.  So I will be able to wire it up manually however I need to.

To confirm what I think i am reading, I can use wires 1-2-3-6 as my RJ45 (data) and either 4-5 or 7-8 as RJ11 (phone)?  I am a big novice on doing my own cables so the more detail the better.

In reference to the grounding comment, your suggesting the electric panel in my house be grounded against the electric panel in this 2nd building?  If the voltage travels through the CAT5 cable and it doesn't pass through the electrical panel at all, how will grounding the panels do any good?
LVL 32

Expert Comment

ID: 34865001
Yes. 1-2-3-6 are for data, FastEthernet or 100BASE-T or whatever you want to call it.  The other pairs are for phone use.  Some older phones require the Black-Yelo pair for additional power provided by an AC/DC transformer (wall wart)...think older Princess phones with lighted buttons.

Your Cat5 cable is calle "non current-carrying conductor"...meaning it was not designed to carry live electrical loads, but is capable of conducting electricity.

If the grounding systems in both buildings are not bonded, then there may exist a difference in grounding potential.  Stray voltage will take the path of least resistance.  So, if Building2 has some sort of stray voltage, short, induced current, static, etc, but the grounding is better in Building1, the voltage may take a path over your Cat5 cable.

Static may knock out your network equipment as it will pass through on its way to ground.

Higher voltage electricity may burn up the wire or shock you.

That's one of the many reasons that fiber optic cable is run between buildings.  A properly permitted and inspected installation never should have passed like that.  (Depending on your where you are...some places don't have many regulations or enforcement.)

I have a detached garage.  A large guage ground wire connects the sub-panel to the main panel, and the neutral in the sub-panel leads back to the main panel.  That's simple when you are providing service to the second building.

For buildings that are on different lots, or have different electrical service, it's not so easy.

Author Comment

ID: 34865738

Thanks for all your info and feedback.  The breakdown of the Cat5 cables and how I need to wire it up manually is what helped me the most so I am crediting you with the solution.
LVL 32

Expert Comment

ID: 34865876
Glad to help.

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