Resources for Michigan Telephone Users
How to Distribute VoIP Throughout a Home
(This also works for a CellSocket or similar device)
One obstacle to replacing traditional phone service with Voice over IP is that for your existing home phone jacks to work, it's necessary to make a change to your inside telephone wiring.
Fortunately, this change is very easy to make. In some cases it's as simple as removing a plug from a jack. Still, a basic understanding of how telephone wiring works is useful before attempting to make such a switch.
A basic wiring primer
Traditional telephone service is provided over a pair of wires. Virtually all telephone wiring installed in the past 50 years or so contains at least two pairs of wires, but that does not mean that all phone wiring is suitable for carrying two phone lines. In today's telephone wiring, each phone line is put on a pair that consists of a solid colored wire (such as solid blue) twisted together with a white wire. Usually this white wire will have a stripe of the same color as the solid wire of the pair (so you would have a blue wire paired with a white wire with a blue stripe), so that you don't get the white wires mixed up. Occasionally you'll see variations on this (for example, the mostly "solid" wire will have a white stripe in it) but you can usually tell what the pairs are, in part because the wires in each pair are twisted together inside the cable.
In newer homes Cat 5 wire is almost always used for communications wiring if not it will probably be at least Cat 3, which uses the same color coding ("Cat" is short for "category", by the way). Cat 5 wire generally has four pairs, while Cat 3 may have a different number of pairs, generally anywhere from three to six.
The primary pair, or "Line 1", is usually the blue and white (with blue stripe) pair. If there is a "Line 2", it is usually placed on the orange and white (with orange stripe) pair. Line three is on the green pair, and line four on the brown pair (if there is a fifth pair, it will be grey, or to use correct telephone company terminology, "slate"). This color coding scheme for multi-line telephone wiring has been used for years.
The outer jacket of this wiring may be blue, green, grey, beige, white, or occasionally some other color (blue is apparently the most popular outer jacket color for Cat 5 wire these days). The same colors are used for 10/100BaseT computer network cables, although the pairs are utilized differently in that situation. With telephone wiring, particularly if Cat 3 wire was used, the actual number of pairs in a cable may vary, but if standards were followed during the installation, the blue and white (with blue stripe) pair is always the primary phone line.
In older homes, you may find a whole different scheme, called "quad" wiring, which containes four wires colored red, green, yellow, and black. The primary phone line is normally the red and green wires. Sometimes you will find a second line on the yellow and black wires, but this is not good practice because, in quad cable, the wire pairs are not twisted together, which can result in "crosstalk" between the two lines. That is the main reason why "quad" wire is rarely seen in homes newer than a decade or so (in fact, it is a violation of a Federal Communications Commission rule to use any wiring that does not meet at least Cat 3 specifications for new and retrofit telephone wire installations made after July 8, 2000).
One other drawback to "quad" wire is that, because the pairs are not twisted, it is much more susceptible to picking up radio-frequency interference (RFI) from nearby transmitters. If you live near a radio station, or even a busy highway where vehicles travel with high-powered transmitters, you may hear interference from these transmitters in your phones. If this is the case, you should definitely consider replacing any "quad" wire with Cat 5 wire (not just Cat 3 Cat 5 has tighter twists and resists RFI much better, and costs only a bit more).
To recap, if you only have one phone line in your home, it is probably on the blue and white (with blue stripe) pair, or if you have older wiring, the red and green wires. This assumes that whoever did the telephone wiring in your home followed the standard color codes. It's possible that in your home you find something different (particularly if the previous homeowner did the wiring), including things that will make you shudder, like seeing wires from completely different pairs used to form a circuit. If this is the case, and you don't know how to fix it yourself, you may require professional assistance to fix things up first.
If you are replacing your traditional phone service with VoIP (or with cellular service using a device such as a CellSocket), you will need to disconnect your inside wiring from the telephone company's outside cables, and then connect your VoIP adapter (or cell service adapter device) to your inside wiring. This page attempts to explain how to do that safely. When we use the term "adapter" or "VoIP adapter", we mean the device that you purchase or that your VoIP provider sends you, that usually has one or two phone jacks on it as well as a way to connect it to your broadband Internet connection. Typical adapters are made by Sipura, Motorola, Cisco, and 8x8, and perhaps a few other manufacturers. You can mentally replace "adapter" with "cell service adapter device" or "CellSocket" in the text below, if that is what you are connecting.
Please note that the following text only covers the "how-to" of replacing your traditional phone service with VoIP service. On this page, we will not deal with the pros and cons of whether you should replace your traditional phone service. We assume that if you're reading this page, you've already made your decision, and may already be a customer of a VoIP company. Also, before we get started, we unfortunately need to say this.....
There is NO WARRANTY on the instructions given on this page. We've tried to make them as clear as possible, but you follow them AT YOUR OWN RISK. In other words, if you follow these instructions and somehow manage to damage your equipment, burn your house down, or cause a blackout affecting half of the United States, WE WILL NOT PAY FOR IT. YOU and YOU ALONE assume all the risk! If you do not agree with this, or even if you are simply uncomfortable with this, you may NOT use the following information. BY USING THE INFORMATION ON THIS PAGE, YOU AGREE NOT TO HOLD THE SITE CREATOR LIABLE IF SOMETHING SHOULD GO WRONG. So, if you are the least bit nervous about this, do yourself a favor and hire a competent telephone technician to do the work.
Also, please note that various adapters or products may carry their own warnings. For example, the Cisco ATA-186 installation manual warns, "Do not connect the Cisco ATA-186 PHONE input ports to the telephone wall jack. To prevent damage to the device or building telephone wiring, connect each Cisco ATA-186 PHONE port to a telephone only, never to a telephone wall jack."
If you choose to ignore any such warnings, you do so at your own risk. Cisco in particular warns, "To reduce the risk of fire, use only No. 26 AWG or larger telecommunication line cord." It may well be that one reason for the warning against using existing telephone wiring is that it may not be possible for the average user to tell if the gauge of the wiring is sufficient. In any case, if you ignore the manufacturer's warning you do so at your own risk.
Note that the Federal Communication Commission's current rules require that copper inside wiring "shall be, at a minimum, solid, 24 gauge or thicker, twisted pairs, marked to indicate compliance with the electrical specifications for Category 3, as defined in the ANSI/EIA/TIA Building Wiring Standards" (The FCC order also states, "Inside wiring material exceeding the minimum requirements specified in section 68.213(c) as amended by this Order may be used and should be marked to indicate those characteristics." And in case you didn't know, the lower the gauge number, the thicker the wire 24 gauge is thicker than 26 gauge).
Of course, we all know that every manufacturer must take great care to cover themselves legally with disclaimers and warnings. If, for example, Cisco didn't issue these warnings and someone hooked up their device to some old, decrepit phone wiring that was three sizes too small, and the house caught fire, the lawyers would be circling like buzzards. Even if it wasn't the fault of their device, but it just looked like the fire started somewhere near the phone wiring, an overzealous lawyer could cause a lot of trouble. So, manufacturers feel compelled to issue such warnings, and we must advise you to follow such warnings. Unless you are willing to personally assume any and all risks associated with not following the warnings, you should indeed follow them explicitly.
So... the following information is given for educational purposes only. We do NOT recommend that you actually do anything mentioned below, but if you choose to do it anyway, you do so at your own risk, period! We also urge you to have a qualified telephone technician or licensed electrician (as appropriate) do any work involving telephone or electrical wiring of any kind. Be sure to follow all fire safety and electrical codes, and observe all warnings in the device manufacturer's printed materials.
And one other thing if your home has the older style "quad" wiring (or worse yet, the really old stuff with individual wires twisted together with no outer jacket), we urge you in the strongest possible way to have it replaced with modern Cat 5 wiring by a competent technician or electrician, in order to avoid any possible risk of fire or personal injury that may be caused by putting excessive current through insufficient wiring! Now, back to our educational material...
Please note that as written, the following instructions ONLY apply to single-family homes with a single phone line. These instructions are NOT intended for use in multi-family dwellings, shared tenant arrangements, or any place where phone lines belonging to more than one customer may enter the building! Also, if you have a home alarm system, please read the section on alarm system telephone wiring before making any changes to your inside wiring.
Now we get started
If your intent is to totally disconnect from your local phone company, you need to isolate your inside wiring from the lines feeding your home, that come from the telephone company central office. You need to do this even if the line seems to be dead, because at some point the phone company could place voltage across that line for one reason or another, and that could damage your equipment, and even possibly start a fire! So here is how to isolate your inside wiring from the telephone company's lines.
On the outside of your home, you should find a telephone company Network Interface Unit. This is the demarcation point between your wiring and the telephone company's wiring. It may not look exactly like the one in the picture at the right, but you will know it because the telephone cable coming to your home from the street, as well as one or more lines from inside your home will go into it. When you open it (usually by undoing a single common screw), you will be able to access the wires going into your home, but not the ones coming from the street. This is by design. There should also be a ground wire coming out of the telephone company's side of the box. It is important to leave the ground wire connected, since it can help guard against lightning damage to your home (in the event that lightning strikes a nearby phone cable).
Once inside the Network Interface Box, you should see one or more sets of screw terminals (two or four screw terminals per line) and short stubs of wire with a standard telephone plug on the end, plugged into a matching jack as shown here. If there is only one line coming into your home, there will probably only be one plug and set of screw terminals. Now, assuming that you are the sole occupant of your home, it should be sufficient to simply unplug all the plugs. Unfortunately, that leaves too much opportunity for Murphy's Law ("anything that can go wrong, will") to come into play. In this case, what can go wrong is a telephone company employee going to the wrong home (yours), finding the plug unplugged, and plugging it back in.
Warning the phone company
You don't want to remove the interface because someday you might sell your home, and the next person to come along may want phone service. So, here is what we suggest:
First, unplug all the plugs and take some black plastic electrical tape (or any other vinyl tape you may have) and wrap the ends of the plugs, so that they cannot be plugged back in without removing the tape. Then, take a stiff piece of cardboard (preferably white) and cut it so it will just fit inside the box when you close the lid. In waterproof ink (some felt-tip ink and most bubble-jet printer ink is NOT waterproof), write something like this in bold letters on the cardboard: "ATTENTION TELEPHONE COMPANY: DO NOT RECONNECT THESE CIRCUITS WILL DAMAGE EQUIPMENT INSIDE!" Shut the lid on the box and screw it down. Then take a label and write the same message and tape it to the outside of the lid using clear waterproof tape. Why? Well, in case you hadn't noticed, these are "trick" boxes. The phone company can open their side AND your side in such a way that the cardboard might stay in the lid. So by putting the message both inside and outside the box, you reduce the chance that it won't be seen.
An even better idea is to use a small hang tag with string (like the tags that some auto repair shops attach to your keys while you have your car in for service). You can write your message on one of those and tie it right to the plug.
Another thing you can do, although you shouldn't need to if you have taped the plugs and left a message inside the box, is to physically disconnect the wires from underneath the screw terminals. But if you do that, you need to tape the ends of the wires so they cannot short out against each other or anything else inside the box. One other thing you can do is to wrap a long nylon tie-wrap completely around the box so that the box cannot be opened without cutting the tie-wrap. In other words, anything you can do to give a phone company employee second thoughts about opening the box and/or reconnecting the plug can't hurt.
If you ever sell your home, please remember to reverse what you have done, so the new owner doesn't have to pay the phone company some outrageous sum to come out and take the tape off of your plug (note that if the tape has left sticky residue on the plug, you might want to clean the plug with a little WD-40 on a rag to remove the adhesive, followed by denatured alcohol to remove the WD-40! And, for goodness sake, LET THE ALCOHOL DRY COMPLETELY before you plug the plug back into the jack alcohol and sparks are an explosive combination!).
Anyway, once you have disconnected all the lines inside the network interface box, pick up a phone inside the home (that is plugged into a previously working jack) and you should hear nothing the line should be totally dead. If it isn't, something is very wrong and you should stop right there and get a telephone technician out to check the inside wiring in your home (assuming you can't figure out the source of the problem yourself).
Plugging VoIP in
Now that you know the line is dead, plug your VoIP telephone adapter into any one of the telephone jacks in your home (using a standard telephone line cord). Connect standard telephones into the other jacks in your home and your whole house is now wired for VoIP.
There is a common misconception that you have to run a wire from the adapter out to the network interface box and connect to the telephone wiring there. Generally speaking, that is not true telephone jacks are wired in parallel, so you should be able to plug the adapter into any working phone jack, and that will feed the signal to the other jacks in your home.
An alarming exception
There is one notable exception, where you cannot just plug your VoIP adapter into any jack, and that is if you have a home alarm system that connects to the telephone line. In that case, you will almost certainly need to connect your adapter to the phone wiring before it reaches the alarm, otherwise the alarm may not work properly (your inside phone jacks will work, but your alarm system will be unable to dial out).
Many home alarms are wired using a RJ31X jack (an 8-pin modular jack, usually located close to one of the alarm's components), and there is a single pair of wires that connects the RJ31X jack to the Network Interface Box outside. If that is your situation, you could disconnect that wire pair coming from the Network Interface Box at the RJ31X jack, and substitute a connection to your VoIP adapter, as shown in the graphic (note that RJ31X jacks may vary in design by manufacturer, so it's remotely possible that the proper screw terminals may not be in the same position as shown on the graphic). If the screw terminals or punch-down connections in the RJ31X jack are numbered, the pair in question is usually on connectors 4 and 5. For additional information on RJ31X jack wiring, including an explanation of how the RJ31X works and why it is used, we suggest you visit the page at HomeTech Solutions entitled How Do I ... Wire an RJ31X Jack?
This assumes that your alarm will work over a VoIP circuit most will, but a few won't, and you probably won't know until you try. Depending on the dialing requirements of your VoIP provider, you may need to have the alarm reprogrammed to dial a "1" plus area code in front of the number it dials, and you want to make sure the unit is dialing out using touch tones rather than dial pulses (many VoIP adapters don't recognize dial pulses, as produced by older rotary dial phones).
If you have a home alarm system and are switching from traditional telephone service to VoIP, we urge you to contact your alarm company for advice and assistance. And be sure to test your alarm system to make sure it's working properly after making any changes to the wiring. It's also worth noting that a few newer alarm systems have the ability to use an Internet connection to "phone home", so your alarm company might be able to bypass the use of your phone line altogether.
Avoid too many ringers
Keep in mind that there may be a limitation on the number of telephone ringers that can be powered by any given VoIP adapter, so turn off the ringers on as many phones as you can to begin with. You can then have someone call you and while the phone is ringing, turn ringers you need on one at a time and see if it causes the volume of the other ringers to decrease. If you switch on a ringer and all the other phones stop ringing, that ringer probably draws too much current (or else you have simply exceeded the number of ringers the adapter can handle) and you should avoid leaving it switched on.
Every modern telephone has a "ringer equivalency number" (REN) that can be found on a label somewhere on the phone. If you have an older phone with a mechanical bell, it is assumed to have a REN of 1.0. In theory, a telephone company line can only support a REN of 5 (five standard ringers on a line), but some folks have connected six or seven without any problem. That doesn't necessarily mean you can do that with one of these adapters, though. The Cisco ATA-186 unit (that has been supplied in the past by VoicePulse and Vonage) also supports up to 5 REN per port, "depending on loop length", which simply means that in a normal home situation you should be able to have five telephone ringers connected with no problem. The Sipura SPA-2000 (currently used by VoicePulse) technical specifications sheet states that the maximum ringer load is 3 REN. We expect that most of the newer adapters currently being shipped to customers would have similar specifications, but it may take some trial-and-error to determine how many ringers the adapter you are using will support.
If you want a phone at the same location where you plug your VoIP adapter into a jack, simply plug a phone line duplex adapter (two jacks to one plug) into the VoIP adapter, or into the phone jack, whichever is more convenient.
All of the above assumes that you are the sole homeowner in your home. If you have more than one line coming into your home, or if you are in some sort of shared living situation, there is one cardinal rule to remember: If your VoIP adapter ever gets crossed with a line carrying live voltage from the phone company, you could destroy it (and possibly cause a fire in the process). So, do whatever you need to (including running totally new wiring, or using only cordless phones with the base unit plugged directly into the adapter) to avoid letting your adapter get crossed with a live telephone company line.
Using VoIP as line 2
It is possible to keep your original telephone service and use VoIP as a second line. In a way you are tempting fate, because you will have the phone company's circuits and your circuits running in the same cable, increasing the risk of getting telephone company line voltage crossed with your VoIP adapter. Be sure you have read the legal disclaimer above before you proceed!
Also, be especially careful of using a two line phone unless you know that it keeps the two phone lines electrically isolated at all times. It should do that, but there's no guarantee that there isn't a cheap, poorly-designed phone out there somewhere that doesn't prevent voltage from leaking from one line to the other, especially if the conferencing feature is used.
With these warnings in mind, connecting a second line is simply a matter of finding an unused pair (normal telephone company usage is that the orange and white with orange stripe wires are line two) and making sure that they are connected to line two at all your phone jacks (if the jack has four wires color coded red, green, yellow, and black, then the orange wire of the cable pair would connect to the yellow wire at the jack, and the white wire with the orange stripe would connect to the black wire in the jack).
Note that in some homes the second pair may not have been connected at all phone jacks, nor for that matter may all of the "line two" pairs be connected together at the point where the home's phone cables come together.
You'll still have to check the Network Interface box outside your home. What you don't want to see is shown at the right the orange pair actually connected. If it is, then unplug and tape the plug associated with that pair, similar to what we told you to do for all the plugs if you were going to totally disconnect from the phone company. You'll have to modify the note you put in the box and on the outside of the box, to basically say not to mess with line two (the orange pair). It might be safer to physically disconnect the orange pair from the screw terminals, but if you do, please don't forget to tape the ends so they can't short against each other, or come in contact with line one!
One pitfall about putting your VoIP adapter on line two is that you absolutely cannot plug your adapter into a phone jack using a standard phone cord unless you have specially wired a jack to reverse lines one and two (if you don't do this, you'll be connecting your adapter to the "live" phone line!). If you go that route, always plug a phone in first to make sure you don't hear a dial tone (or anything else!) before you plug your adapter in.
Don't feel like rewiring a jack? Well, if you happen to have a modular plug crimper and some plugs and flat cable, you could make a "pair swap" cable, by reversing the positions of the red and black wires, and also reversing the positions of the green and yellow wires at one end of the cable only (so that yellow and black are on the two center pins, and red and green on the two outer pins. Again, this is done at only one end of the cable, while the other end is attached to the plug in the normal manner.
What this does is reverse lines one and two that is, line one at one end of the cable will be line two at the other, and vise versa. But if you do that, you have to make sure that no one in your home will get the bright idea to exchange the pair swap cable with a regular one. Also, DON'T DO THIS WITH AN ADAPTER THAT SUPPORTS TWO LINES, if lines one and two both appear on the same jack (we don't know of an adapter that does this, but that doesn't mean there isn't one out there somewhere).
Again, DO NOT USE THE ABOVE CABLE WITH A TWO-LINE ADAPTER that puts both lines on the same jack if you do, the "live" line one will blow out the second line on the adapter! Instead, you could make a cable that only uses one pair, BUT you will have to be careful about which end is plugged into where:
And, there is a third way that's easier yet, but we're not going to mention it because it makes it FAR too easy to plug into the wrong line and blow out your adapter. Doing it that way is a disaster waiting to happen. We think that rewiring the jack nearest the adapter to reverse line one and two is the safest way, because it's not likely anyone will move the adapter to another jack, but people do unplug and replug cords, or sometimes swap cords around to get a longer or shorter one on a particular phone. Whatever solution you devise, ask yourself whether someone else in your home could plug in the wrong cord (or plug it into the wrong jack) and cause problems.
Please remember the number one rule: Before connecting your VoIP adapter to any wall jack, plug a phone in first and LISTEN to make sure the line is dead!
What to do in an apartment or condo
Your ability to retrofit the wiring in a multi-unit dwelling depends on how much you know about telephone wiring, how much access you have to your telephone wiring, and in particular, whether you can break the connection to the telephone company's network in such a way that it cannot be reconnected without your knowledge and approval.
Obviously, if you own the unit you live in, you're in a much better position to control the wiring that is physically within your living unit, whereas in a rented apartment you're basically gambling that no one will reconnect the wiring without getting your consent first. In any case, isolating the wiring in these kinds of units basically consists of finding out where the wires from the outside world come into the apartment, and breaking the connection there (in such a way that you can easily reconnect it when you move out).
In this, you're pretty much on your own. Our advice is to get a cordless phone (one that supports multiple handsets if you need "extensions" businesses use these, so you can find them at any major office supply chain store) and plug it directly into the adapter, so you don't have to mess with apartment wiring. But, if you DO try to isolate the wiring in your apartment anyway, the earlier advice about plugging in a regular phone to check the line for noise or dial tone BEFORE connecting your equipment applies even moreso here. And remember, you ARE gambling that no one will reconnect the line without your knowledge or consent.
Special considerations for business customers
Because some VoIP companies offer a business class service, there are going to be companies that want to hook their VoIP service into a business phone system or a PBX. There are two common problems, and both have workarounds.
The basic problem appears to be that certain VoIP adapters do not generate what is known as the CPC signal. Without getting into a long technical dissertation, this is a momentary drop in power on the line (as if the line were completely disconnected for a few moments), or a polarity reversal on the line. Either of these signals can be used to cause telephone hold circuits to release automatically. The CPC signal can also be useful with some consumer grade equipment, including telephones with "hold" buttons and some types of answering machines. However, most residential customers won't notice much of an impact from the lack of the CPC signal.
On a "normal" telephone line, this voltage drop or polarity reversal usually occurs if you hold the line open after the other party has hung up (to a person listening on the line, it sounds like either just a single click, or a click, a VERY short pause of "dead air", and another click. But in either case, it happens very quickly so if you're not paying close attention you could easily miss it!).
As mentioned, the purpose of this signal is to release a line inadvertently left on "hold." So, when connecting a small business phone system that is designed to work with regular business phone lines to a VoIP adapter that does not supply the CPC signal, the problem appears to be that if a call is accidentally left on hold, the line will never release. In some slightly more expensive systems, it's possible to "park" a call while waiting for another extension to pick it up, and a "parked" call might never be released without manual intervention. Thus, probably with distressing regularity, the line gets held open because someone put a call on hold and forgot about it, and with no CPC signal the line was never released.
If you think you have this problem, contact your VoIP provider they may be able to enable CPC on your adapter. Failing that, we can point you to a place where you can probably find a solution to this problem, but please be aware that we've not personally tested any of this equipment. Reports from actual users of this equipment would be welcome.
Go to Mike Sandman's "Wizard's Tool Box" page and scroll about � of the way down the page search for the items entitled "CPC GENERATOR", "MAKE A SILENCE DETECTOR, TO CREATE A CPC SIGNAL", and "CallSaver: Disconnects a Phone Line that's Left Off Hook!" ONE of these devices will probably solve your problem, depending on the VoIP adapter in use and how it actually reacts when a phone is left off-hook after the call is ended (for example, VoicePulse returns a fast busy signal when the other end disconnects, and Vonage sometimes does this as well, so from the descriptions given it is likely that the "CPC GENERATOR", which detects a dial tone or a busy signal, would be the device to use to create the CPC signal).
We cannot guarantee that any of these devices will work, nor give you any technical assistance on these devices. Mike also offers a CPC Technical Bulletin on his site, that explains what CPC is and that may help you decide which product you need. A similar device that may be more suitable in a multi-line installation is the Max Terminator Disconnect Unit by Electronic Tele-Communications.
There is one other possible reason a business might run into problems. If you have a really fancy PBX, it might not use regular phone lines it might instead use "trunks" (if, indeed, it uses analog circuits at all). What comes out of a VoIP adapter unit is a telephone "line", not a "trunk" it does not have the "wink start" signal needed by some types of PBX equipment. On some PBX's you simply need to connect the line from the VoIP adapter to an analog port, while on others, the secret to getting around this is to configure the PBX to treat the connection to the VoIP adapter as though it were a two-way Foreign Exchange (FX) line (one on which both outgoing calls may be placed, and incoming ones received). Most PBX's can handle this, and some can even compensate for the lack of CPC on an FX line. For those that cannot, see the previous paragraph you may still need to insert a piece of equipment that generates the CPC signal.
One person who posted a message in an online forum stated that he had no problem getting a VoIP adapter to work with Avaya/Lucent partner systems and Nortel Mics/cics sytems. He stated that these systems treated the adapter lines just like 1FB'S. He did note, however, that the aforemented "missing CPC" problem existed.
Thanks to Marcelo Rodriguez of Voxilla.com for his help with some of the text on this page. Specifically, I gave him permission to copy the text from an earlier version of this page to his site, and to edit it for clarity. During a subsequent update of this page, I incorporated some (but not all) of his edits into my revised text.
If you have a suggested correction or addition to this page, please send an e-mail to the following address:
I'm sorry that you can't cut and paste this address, or click on it to send e-mail, but this is done in an attempt to foil automated spam e-mail address harvesters.
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