sundance-communications.com/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring jacks and plugs help

What are the companion/mating plugs called that go into RJ11 and RJ14 jacks?

Or is it one of those deals where an RJ11 or RJ14 can be either a plug or a jack?

Is a four contact jack an RJ11, and a six conact jack an RJ14?

The devices that use RJ11 and RJ14 jacks can be found with either two, four, or six contacts.

The phone cords I've seen with the modular plugs have either four or six conductors in the cord. If you use two, four, or six conductor cords, are they compatible with the different number of contacts on the RJ11 and RJ14 jacks? That is, do the devices simply use what's delivered to them, and ignore missing wires? For example, if we use a phone with a six contact jack, and hook a four conductor phone line to it, will the phone still work in some capacity? If you run a six conductor cord to a 2 or 4 contact jack, does it still work OK?

rb,
These 2 links should help you...check here , to help clarify some of the "naming confusion", and also here. ..to help clarify some of the "application confusion".

WOW! Good info. Thanks. If I read and digested everything correctly, it seems that:

A. RJ11 and RJ14 jacks are physically the same.

B. The RJ11 jacks can have two or four contacts.

C. The RJ14 jacks can have two, four, or six contacts.

D. A four or six conductor cord can be used with either of the jacks.

I'm glad we could assist you in clarifying some of the "RJ" naming and application confusion.

In follow-up to your original post, I think you'll find reviewing this thread very interesting and informative.

>> RJ11 and RJ14 jacks are physically the same.

No. An RJ11 is a single line jack, a 6p2c. A 6p4c or 6p6c jack may be wired as an RJ11.

An RJ14 is a two line jack, a 6p4c. A 6p6c jack may be wired as an RJ14. A 6p2c jack cannot be wired as an RJ14 as it is missing the connections for the second line.

>> The RJ11 jacks can have two or four contacts.

Or even six contacts.

>> The RJ14 jacks can have two, four, or six contacts.

No. A RJ14 requires at least four contacts, If there are only two contacts you lose the second line and it is an RJ11, not an RJ14.

>> A four or six conductor cord can be used with either of the jacks.

Correct. But a two conductor cord (quite common) can only handle a single line. You *can* use it in an RJ14, but you'll have no dial tone on the second line and the client *will* complain.

Thank you. Very good explanation.

As you no doubt realize, there's a lot of misinformation and ambiguity surrounding what could be a somewhat simple topic. Lots of mislabelling and identifying of parts and components.

I'm a total beginner in the telephone wiring area. What I was doing was trying to use my two phone wall mount jacks (line 1 on one, line 2 on the other) to go to a FAX on one line, and my DSL pc on the other, with a single line phone switched between them.

I found a nice Lucent Technolies switch for bringing two lines in (L1+L2)and switching between them.

I started out at the junction box outside the house, and verified wire colors in the cable going into the house.

THen I popped the wall mount jack cover and took a look at how the jacks were wired. Once I was comfortable that convention had been followed to that point, the rest was relatively simple.

I just went to Rat Shack and got some 3 way combiner jacks and a splitter that has two jacks for a L1 and L2 cord in, and L1+L2 out to the switchbox, and a few extra cords. Works good.

I've copied all the good stuff you guys have told me to a nice WordPad file for permanent storage and use in case I ever need to do anything else of this sort.

rb,

Glad the board could help you.

Just remember, the RJ designations are used for a wiring methodology, not a piece of hardware. Many different pieces of hardware can be wired to conform to a different RJ designation.

Have a wonderful and prosperous New Year.

I am happy in being able to share what comes as so quickly to me with someone who benefits. RB, please feel free to come back anytime for assistance. Whether it be phones, wiring, cell phones, computers or even security/audio, there are a bunch of folks here who can help.

Many visitors or new members have a matter at hand that might seem complex at the time, but in reality can be easily resolved in a few minutes. That is the whole purpose of this forum. Your reply and comments are greatly appreciated.