CAT-3 Has 8 Wires? And Phone Cable Has 12 Wires?

[jaykchan@hotmail.com]

I am examining the phone wiring in my house, and I have found two phone
cables that I don't quite understand:

- There is a phone cable that connects a phone outlet to the phone
distribution block. It is clearly marked as CAT-3 cable; but it has 8
wires (yes, I have counted them individually). According to a picture
in a home networking book, a CAT-3 cable should only have 6 wires.
Strangely, the CAT-3 cable that I bought from HomeDepot has 4 wires.
Now, I am really confused.

- There is a phone cable coming from the phone company. This cable has
12 wires. What's it? Where can I find it in stores? I am trying to
extend this line by 5 feet. Therefore, I am looking for a matching
phone cable.

Thanks in advance for any info.

Jay Chan

[John Hines]

jaykchan@hotmail.com wrote:

>- There is a phone cable that connects a phone outlet to the phone
>distribution block. It is clearly marked as CAT-3 cable; but it has 8
>wires (yes, I have counted them individually). According to a picture
>in a home networking book, a CAT-3 cable should only have 6 wires.
>Strangely, the CAT-3 cable that I bought from HomeDepot has 4 wires.
>Now, I am really confused.

4 pair wire. I've not heard that cat-3 only had 3 pairs, only 3 pairs
were actually used in most networking uses, as the original design
allowed for a phone line along with the network lines, however in real
life, this is rarely used.

>- There is a phone cable coming from the phone company. This cable has
>12 wires. What's it? Where can I find it in stores? I am trying to
>extend this line by 5 feet. Therefore, I am looking for a matching
>phone cable.

6 pair wire

Yep, the phone company is the primary user of this. Use multiple pieces
of cat-x wire to extend it.

AFAIK, all cat-3+ wire has 4 pairs, the biggest difference is how
tightly the twists are in the wire, the tighter twists allow a higher
frequency, and thus a higher data rate.

For plain ol' telephone service, simple wire is enough (sometimes called
cat-1), but using higher grades of wire is not a problem. So use cat-3
or cat-5 and as many cables and pairs as you have phone lines.

[BruceR]

Cat3 is 8 conductor (4 pair) and the main difference between it and Cat
5 is the twists per foot - not a concern for phone wiring. The 6 pair
cable the phone company installed is designed to handle up to 6 phone
lines (one pair per line). To extend a single phone line you only need
one pair so use whatever you have on hand to extend the phone line and
leave the unused pairs alone.

From:jaykchan@hotmail.com
jaykchan@hotmail.com

> I am examining the phone wiring in my house, and I have found two
> phone cables that I don't quite understand:
>
> - There is a phone cable that connects a phone outlet to the phone
> distribution block. It is clearly marked as CAT-3 cable; but it has 8
> wires (yes, I have counted them individually). According to a picture
> in a home networking book, a CAT-3 cable should only have 6 wires.
> Strangely, the CAT-3 cable that I bought from HomeDepot has 4 wires.
> Now, I am really confused.
>
> - There is a phone cable coming from the phone company. This cable
> has 12 wires. What's it? Where can I find it in stores? I am trying to
> extend this line by 5 feet. Therefore, I am looking for a matching
> phone cable.
>
> Thanks in advance for any info.
>
> Jay Chan

[jaykchan@hotmail.com]

> 4 pair wire. I've not heard that cat-3 only had 3 pairs, only 3 pairs
> were actually used in most networking uses, as the original design
> allowed for a phone line along with the network lines, however in
real
> life, this is rarely used.

I see. This means the cat-3 that is in my house is normal. The book
clearly shows a cat-3 cable that has 6 wires (the book is called "Home
Networking" from Sunset). May be the author has already cut out one
pair from the cat-3 cable before taking the picture.

Still, I don't understand why the cat-3 cable that I have bought from
HomeDepot only has 4 wires. May be this is cheaper to manufacture this
way. And may be they still can call it a cat-3 cable if they maintain
the correct tight twists on the wire regardless the fact that it only
has 4 wires (2 pairs).

> Yep, the phone company is the primary user of this. Use
> multiple pieces of cat-x wire to extend it.
Good to know this. Thanks.

Jay Chan

[jaykchan@hotmail.com]

> The 6 pair cable the phone company installed is designed to handle
> up to 6 phone lines (one pair per line).

Thanks for the info. This means I don't really need to match the phone
line exactly when I extend the phone line from the phone company
because I don't expect to subscribe more than one phone line.

Jay Chan