Wiring - Technical References


Western Electric:

This standard defines the colour combinations for the 25-pair voice cables on the back of a BIX block.

There is a primary colour and a secondary colour. The colours are:

Primaries Secondaries
white
red
black
yellow
purple
blue
orange
green
brown
grey

They are mixed by matching each of the secondaries with the primaries in order. i.e. white/blue, white/orange, white/green, white/brown, white/grey, red/blue, red/orange, etc.


RJ-45:

8-wire RJ-45's (as used in 10baseT ethernet, ISDN installs in Toronto (and presumable other places), etc. has a specific order for the colours available in most category 5 cable (also called UDP 5 cable). The order of pairs is:

Colour pairs Pair number Pin numbers
white/blue
white/orange
white/green
white/brown
pair 1
pair 2
pair 3
pair 4
pins 4,5
pins 3,6
pins 1,2
pins 7,8

The pairs are installed as follows (viewed with cable facing away):

   ___                              
  |\   \                            
_ |  \ __\_                         
_\|   | 8 |--.____Pair 4            
_\|.  | 7 |--'                      
 \||\ | 6 |----------------.        
  || || 5 |--.____Pair 1   |__Pair 2
  | \|| 4 |--'             |        
  |   | 3 |----------------'        
   \  | 2 |--.____Pair 3            
     \| 1 |--'                      
       ~~~~                          


T1 Routers and Interface Cables:

Routers get connected to T1s like this:


       .-- Telco-installed cable        V.35 serial cable       Ethernet
       |                                          |                |
       v    +---------------+       +---------+   v   +--------+   `->|
    /\/\,---| DS1 Interface |-------| CSU/DSU |-------| Router |------|
            +---------------+   ^   +---------+       +--------+  ^   |
                                |                                 |
           T1 Interface Cable --'                Ethernet cable --'

Pinout for the T1 Interface Cable:

Colour DB15 RJ-45
(RJ-48)
White/Orange
Gnd (Orange)
White/Blue
Gnd (Blue)
Orange/White
Blue/White
1
2
3
4
9
11
5
8
1
7
4
2

Manufacturers of Parts:



Paul Chvostek <[email protected]>
1998?