23rd February, 2026



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Standards for terminating of RJ45 connectors.

When network devices have being connected some cables are used terminated by RJ 45 connectors. All cables used in building  of Structured Cabling Systems no matter of construction or category have four twisted pair colored in different way.

1 pair white/blue-blue;

2 pair white/orange-orange;

3 pair white/green-green;

4 pair white/brown-brown;

So to connect two network devices by cable first  it have to be terminated in both ends by RJ45 connectors. There are two types of connectors – Male RJ45 connector(plug) and Female RJ45 socket(jack):

Male RJ45 connector          Female RJ45 socket

Male RJ45 connectors  most recently are used in patch cables and Female RJ45 sockets are used in telecommunication outlets and in patch panels. According to Structured Cabling standards EIA/TIA  568, ISO/IEC 11801 or EN 50173 both ends of the cabling must be terminated on the same pins. To this end, the pairs, pins and their colours are standardised. There are two permitted versions:  EIA/TIA 568A and EIA/TIA 568B, these are only different in the pair termination layout. (green and orange [Pairs 2 and 3] being reversed).

 

STANDARD 568A

 

STANDARD 568B

There is no relevant technical grounds to recommend one or the other version, the reason for the differences is purely historical.Of course, it is in the interest of the customer to have all installations using the same version.
Important: The both ends of the cable are connected as either 568A or 568B. A mixing of versions will show a measurement failure in the Wire-map tests.So to check wiring we take both  cables ends as shown  below and coloring must be equal on both sides.
Note: When making Hub-to-Hub connections or PC to PC, in order to connect the transmit to receive pairs, one end should be terminated as 568A and the other as 568B. This cable is known as “crossed cable“. Modern hubs have an “X” port that allows “straight” patch cords to be used.

Incoming search terms:

T586brj45 standard b, .

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