8P8C
See modular connector for numbering of the pins in these 8P8C modular connectors.
The assignments of wire pairs to plug and jack pins are as follows:
| Pin | T568A Pair | T568B Pair | Wire | T568A Color | T568B Color | Pins on plug face (jack is reversed) |
|---|---|---|---|---|---|---|
| 1 | 3 | 2 | tip |  white/green stripe |  white/orange stripe |  |
| 2 | 3 | 2 | ring |  green solid |  orange solid | |
| 3 | 2 | 3 | tip | white/orange stripe | white/green stripe | |
| 4 | 1 | 1 | ring |  blue solid | blue solid | |
| 5 | 1 | 1 | tip |  white/blue stripe | white/blue stripe | |
| 6 | 2 | 3 | ring | orange solid | green solid | |
| 7 | 4 | 4 | tip |  white/brown stripe | white/brown stripe | |
| 8 | 4 | 4 | ring |  brown solid | brown solid |
Note that the only difference between T568A and T568B is that pairs 2 and 3 (orange and green) are swapped. Both standards wire the pins "straight through", i.e., pins 1 through 8 on one end are connected to pins 1 through 8 on the other end. Also, the same sets of pins are paired in both standards: pins 1 and 2 form a pair, as do 3 and 6, 4 and 5 and 7 and 8. The different pairs in an ethernet wire have different impedances, so an orange pair can not be connected directly to a green pair. In order to connect two different pairs together, a hub or switch or higher level piece of equipment like a router must be placed between the two. Splicing two cables together will result in improper termination and reflections will occur in the line. These reflections will cause errors and lower the available throughput in the wire.
UTP cables terminated according to T568A on one end and T568B on the other end are known as Ethernet crossover cables.
6P6C
Holding the connector in your hand tab side down with the cable opening toward you, the pins are numbered 1–6, left to right.
| Position | Pair | T/R | ± | RJ11 | RJ14 | RJ25 | Twisted pair colors | 25-pair colors | Old colors[a] | German colors[b] | Australian colors |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 3 | T | + | T3 | white/green | white/green |  white |  pink | orange | ||
| 2 | 2 | T | + | T2 | T2 | white/orange | white/orange |  black | green |  red | |
| 3 | 1 | R | - | R1 | R1 | R1 | blue |  blue/white | red | white | blue |
| 4 | 1 | T | + | T1 | T1 | T1 | white/blue | white/blue | green | brown | white |
| 5 | 2 | R | - | R2 | R2 | orange |  orange/white |  yellow | yellow | black | |
| 6 | 3 | R | - | R3 | green |  green/white | blue |  gray | green |
- ^[a] While the old solid color code was well established for pair 1 and usually pair 2, there are several conflicting conventions for pair 3 (and sometimes even pair 2). The colors shown above were taken from a vendor of "silver satin" flat 8-conductor phone cable that claims to be standard. 6-pair solid (old) bellwire cables previously used by the Bell System use white for pair 3 tip but some vendor's cable may substitute orange for white. At least one other vendor of flat 8-conductor cable uses the sequence blue, orange, black, red, green, yellow, brown and white/slate.
- ^[b] This color scheme originates in the (withdrawn) national standard DIN 47100. The scheme shown here is the correct color code for interfacing with the RJ connector standards.
--Reverend Loki (talk) 21:20, 17 August 2011 (UTC)