Telecom Tips - Wiring Your Home For VoIP Service

by Brian McConnell

Broadband telephone service enables you to consolidate all of your voice and data service to run over a single fast Internet connection. The problem is that home telephone wiring was not designed with broadband in mind. Here's how you can fix this.

Connect A Cordless Phone System To The VoIP Adapter

This is the easiest thing to do. Find a good multi-handset cordless phone system. These systems allow multiple cordless handsets to share a single phone line, to transfer calls from handset to handset, and in general act like a small intercom system. You can buy these through numerous home electronics vendors, as well as telecom retailers such as Hello Direct.

Connect Ethernet Phones To Your Home Network

If your VoIP service directly supports third-party VoIP phones (some do, some don't), you can directly connect compatible telephones to your household LAN wiring or to your wireless LAN. Most VoIP providers support the SIP (session initiation protocol) standard, which is supported by most VoIP telephone handsets.

NOTE: although SIP is the leading VoIP standard, some VoIP carriers do not interoperate with all SIP devices. Vonage, one of the best known broadband phone companies only supports Vonage branded terminal adapters. VoicePulse, on the other hand, advertises support for all SIP compliant devices. Generally speaking, I recommend carriers that support open standards, otherwise you get locked in with proprietary hardware.

You can find SIP phones through telecom retailers including Hello Direct and VoIP Supply. Be sure to verify that the equipment is compatible with your broadband provider. VoIP is still bleeding edge, and not everybody's hardware plays nice with each other.

SIP phones generally provide better control over calls (e.g. access to better call transfer and conference calling features, message waiting indication, etc). This approach also eliminates the need to have a VoIP adapter in some cases, as the phones can be directly connected to your LAN/WLAN without any intermediate hardware.

The problem with SIP phones is that they are expensive. It's not uncommon for good net phones to cost over $300, which is a bit much for household telephones, or even most office phones.

Rewire Line 2 To Your VoIP Adapter

NOTE: Only do this if you are not using DSL service on a separate telephone line, and know what you are doing with telephone/data wiring. If not, hire a contractor to do this for you. If not done correctly, you can damage your equipment.

Most homes are wired for two incoming telephone lines. Your telephone service enters the house through a single connection called a point of entry. This is a four wire terminal, two wires for each telephone line. There should be four color-coded wires (red and green for line 1, yellow and black for line two).

RJ14 (Two-Line) Telephone Wiring


What you need to do is to disconnect the yellow and black wires between the point of entry and your inside wiring so that line 2 (yellow+black) inside wiring is not connected to the public telephone network. Leave line 1 (red+green) connected as is.

IMPORTANT: you must be certain that you have disconnected line 2 inside wiring (yellow+black) from the outside telephone network, otherwise you can damage your equipment.

Next, you will connect the yellow and black leads that were connected to the telco point of entry to line 1 on the VoIP terminal adapter. The easiest way to do this is to buy a modular jack from a local electronics store. Wire the jack as follows:

inside wiring black --> green terminal on modular jack

inside wiring yellow --> red terminal on modular jack

Then connect a standard phone cord from the modular jack to the VoIP terminal adapter.

Wiring Diagram For VoIP On Line 2 House Wiring


Telephones connected to line 2 will now see the VoIP adapter as they would the public telephone network.

Potential Pitfalls

Wiring line 2 to your VoIP adapter will enable you to receive and place VoIP calls from any telephone, even old rotary dial telephones. This is cool, and enables you to use VoIP just like your regular primary line.

The main risk in rewiring your house is the potential whoops factor if you wire the system up wrong. It's unlikely you'll damage the telephone network (it's designed to take a beating), but you can easily nuke delicate terminal equipment.

Another issue to be aware of is that older telephones with electromechanical ringers draw a lot of current to ring their bells. Terminal adapters are generally designed to be used with newer self-powered phones that do not use current from the telephone line to power the ringer. Don't connect a lot of vintage rotary dial telephones to line 2, they'll overwhelm the terminal adapter. At best this will cause the phones not to ring. At worst it could damage the terminal adapter.

Again, if you have any doubts about this, hire a local phone/LAN wiring guy to do this. It'll take a half hour or less.

Further Reading

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2005-04-25 23:54:37
Home Structured Wiring Considerations
One advantage of a new home is the structured wiring package that usually comes with it. In my system, the plain-old telephone service (POTS) telco interface goes through a patch panel with RJ-45 connectors.

Connectors like this USOC Splitter, 8x8 Plug / 4 (8x2) Jacks from L-com are quite useful in splitting out a RJ-45 with 4 twisted pairs to 4 RJ-11 jacks. This enables running POTS side-by-side with VOIP (as I did for a while), or two VOIP services. For example, I will keep Vonage for my business line because I can run a fax over it. But BroadVoice has a good international plan.

2005-04-26 00:39:36
Home Structured Wiring Considerations
Unfortunately, my house was built in the 1930s, so the wiring is a bit old.

I also recently decided to banish post WWII-era telephones from my house. I've grown tired of replacing overpriced defective intercom phones every year or so (and generally think today's telephones are ugly and badly designed). My old rotary dial phones are built like tanks and have outlived many of my relatives.

There's something to be said for these older phones. They sound great, and they don't fall apart like the cheap made-in-a-Chinese-prison stuff that's standard fare at the consumer electronics stores these days.

However, it's a bit of a trick to get 70 year old technology to work with the latest toys. It does work though. People like to villify the phone company, but somehow I doubt programs written for Windows 2000 will work on Windows 2070 (which probably won't even exist). My circa 1940 rotary phone worked on the first try. Pretty amazing when you think about that from a backward compatability standpoint.