Network Wiring
Unshielded twisted pair (UTP) cabling
is, in essence, straightforward to install. However, it can be the source of
many problems and conflicts. The way to avoid such problems is to agree on a
standard to adopt for a particular organization or building. The basis
behind this information is simply to provide a standard which will be used
to cable the ING networks.
The
Cabling Category
There are many cabling categories available, most of which have been
designed for specific tasks. The majority of networks tend to use UTP of one
category or another and thus this can be considered to be an industry
standard.
Within the ING we will use a minimum of UTP Category 5 cable because this
is the simplest category which supports up to 100 Mbps.
UTP Category 5 cable consists of four pairs of cable.
The Pairs
The pairs of wires in UTP cable are color coded so that the same wire may
be identified at each end of the cable. In addition, they are grouped into
pairs so that the pairs can also be identified at each end. The UTP Category
5 cable that we use on site contains 4 pairs of wires colored thus :
(1) a solid color (e.g. blue, orange, green or brown) with the other one
of the pair being solid white or
(2) a solid color (e.g. blue, orange, green or brown) with the other one of
the pair being the same solid color striped onto a white background.
There are different color schemes available but we use the scheme that
corresponds to the Electronic Industry Association/Telecommunications
Industry Association’s Standard 568B. This scheme is shown below :
Wire pair 1: White with Blue stripes
and Blue
Wire pair 2: White with Orange
stripes and Orange
Wire pair 3: White with Green stripes
and Green
Wire pair 4: White with Brown stripes
and Brown
The Cable
Connectors
The cable jacks that are to be used are the Registered Jack 45 (RJ-45)
with the associated pin numbering scheme.
For 10BaseT cabling the IEEE specification states that two twisted pairs
are required. These pairs should be connected to pins 1 and 2 and to pins 3
and 6. Thus, only 4 of the 8 pins are used.
The Wiring Schemes
The wiring schemes that will be used within the ING are
(1) The EIA/TIA-568A RJ-45 Wiring Scheme and
WG|G|WO|Bl|WBl|O|WBr|BR
(2) The EIA/TIA-568B RJ-45 Wiring Scheme.
WO|O|WG|Bl|WBl|G|WBr|BR
| 568-B
Wiring (RJ-45) |
. |
568-A
Wiring (RJ-45)
|
|
<RJ-45 Pins 1-8
Facing Up>
|
| 1 |
2 |
|
3 |
|
4 |
5 |
|
6 |
|
7 |
8 |
| . |
. |
|
. |
|
. |
. |
|
. |
|
. |
. |
| . |
|
. |
|
. |
|
|
. |
| . |
|
. |
|
. |
|
|
. |
| . |
|
. |
|
. |
|
|
. |
| . |
|
. |
|
. |
|
|
. |
| Orange
pair 2 |
|
. |
|
Blue
pair 1 |
|
|
Brown
pair 4 |
|
|
|
<Green
Pair 3> |
|
|
|
|
| Pair
# |
Wire |
Pin
# |
| 1
- White/Blue |
White/Blue |
5 |
| Blue/White |
4 |
| 2
- White/Orange |
White/Orange |
1 |
| Orange
White |
2 |
| 3
- White/Green |
White/Green |
3 |
| Green/White |
6 |
| 4
- White/Brown |
White/Brown |
7 |
| Brown/White |
8 |
|
568
B Diagram
|
|
|
<RJ-45 Pins 1-8
Facing Up>
|
| 1 |
2 |
|
3 |
|
4 |
5 |
|
6 |
|
7 |
8 |
| . |
. |
|
. |
|
. |
. |
|
. |
|
. |
. |
| . |
|
. |
|
. |
|
|
. |
| . |
|
. |
|
. |
|
|
. |
| . |
|
. |
|
. |
|
|
. |
| . |
|
. |
|
. |
|
|
. |
| Green
pair 2 |
|
. |
|
Blue
pair 1 |
|
|
Brown
pair 4 |
|
|
|
<Orange
Pair 3> |
|
|
|
|
| Pair
# |
Wire |
Pin
# |
| 1
- White/Blue |
White/Blue |
5 |
| Blue/White |
4 |
| 2
- White/Green |
White/Green |
1 |
| Green/White |
2 |
| 3
- White/Orange |
White/Orange |
3 |
| Orange/White |
6 |
| 4
- White/Brown |
White/Brown |
7 |
| Brown/White |
8 |
|
568
A Diagram
|
|
|
Notes for wiring diagrams above:
1. For patch cables,
568-B wiring is by far, the most common method.
2. There is no difference
in connectivity between 568B and 568A cables. Either wiring should
work fine on any system*. (*see notes below)
3. For a straight through cable, wire
both ends identical.
4. For a crossover
cable, wire one end 568A and the other end 568B.
5. Do not confuse pair numbers
with pin numbers. A pair number is used for reference
only (eg: 10BaseT Ethernet uses pairs 2 & 3). The pin numbers
indicate actual physical locations on the plug and jack.
|
Normal drop cable
For a normal "straight through" drop cable, the EIA/TIA-568B
RJ-45 Wiring Scheme will be used at both ends.
Cross-over drop cable
For a cross-over drop cable, the EIA/TIA-568B RJ-45 Wiring Scheme
will be used at one end and the EIA/TIA-568A RJ-45 at the other end.
Furthermore, these cables will only made using RED
UTP Category 5 cable.
Cabling between wall outlets and patch panels will be done using the EIA/TIA-568B
RJ-45 wiring scheme at both ends.
