Re: PBX For Home

I want to install a PBX system (landline) in my home. I've heard,
> from sellers/installers, that you must have an individual wire from > each jack going to where the phone line comes in (i.e. a different > wire from each jack to one central location -- where the PBX would > plug in). Before I order a system, I want to make sure that I have > the proper wiring. I do not want to re-wire my home.

I'm not exactly sure of what you're saying, but first let's keep our defintions clear: A "trunk" is the line(s) between your home and the central office. An "extension" is one of the telephone sets in your house. Sometimes extensions are referred to as lines, but I'd rather use "extension" to be clear.

Anyway, historically a PBX does three functions:

1) Connects incoming trunk calls to an extension phone. 2) Connects outgoing calls from an extension to an outside line (trunk). 3) Connects extension to an extension.

To do this, all wiring, both trunks and extensions, must come to a central place to be connected to the PBX. All extensions must have their own wire to the PBX to be rung uniquely.

Your trunk line(s) probably all terminate in the same place in a junction box in the basement, after coming in from the demarc box outside.

However, your extension lines may or may not be unique. Some wires may go out individually to each extension (good for your purposes), but others may be extended from one extension to another (bad for your purposes).

1) How do I check if I have this wiring in my home?

You need to physically trace each extension and trunk wire. You must know everything (where it's going and what it's connected to) about any wire you connect to your PBX, regardless of whatever PBX you get. In our old house, one pair of phone wires (yellow-black) contained electric power for old dial lights--you sure don't want to hook up a legacy set up like that to a PBX! You must be sure there's no legancy connections on your wiring.

2) Most sellers say that if I do have this wiring, the Merlin Legend > or Magix system is the only way to go. Are there any other Avaya/ > Lucent/even Nortel systems that would work?

There may be some PBXs in which the phone is addressed digitally instead of physically. In that case you may get away with common wiring. However, the PBX and telephone sets will be more costly.

I have no idea of modering PBX offerings. In the past, the Bell System and others had systems designed especially for home use. For home use a key system may be a better deal. If you plan to have fancy phones at each extension you might be better off with a key system. Anyway, I suspect there are vendors who produce economical modest sized systems that might meet your needs.

Indeed, the real answer to your question is not about the wiring, but what is it that you expect your telephone system to accomplish?

One problem I forsee in a home is that if an outside caller requests a particular extension -- say daughter's bedroom -- and daughter is not in her room, the bedroom phone will ring and not be answered. You need to work out who will be answering incoming calls in your family and what switching will be done in response. Unless your house is extremely large or you are talking about a large property with out buildings, people will tend to just yell for another family member than pick up a phone and dial an extension in which someone may or may not be there to answer. (Kid in bedroom wants parent, does the kid call the basement, dining room, living room, or kitchen? Easier to yell than make 3 calls.)

Another issue is that callers may not be patient enough to work through your PBX procedures.

One historical function of a PBX was to switch outgoing calls to the proper trunk to save money -- perhaps a city line, suburban line, or WATS line. But home WATS is cheap now, plus there are cell phones.