what is the difference between T568A and T568B

RJ45 connector and twisted pair have two connection methods: T568A or T568B. These are two international standard wiring sequences for CAT5E network cables using twisted pairs in order to achieve performance indicators and unified wiring specifications.

So, what is the difference between T568A and T568B?

1. Different standard

Network cable T568A: white-green, green, white-orange, blue, white-blue, orange, white-brown, and brown.

Network cable T568B: white-orange, orange, white-green, blue, white-blue, green, white-brown, and brown.

The meanings of the pins are as follows:

Output data (+)                 (white-orange)
Output data (-)                  (orange)
Input data (+)                    (white-green)
Reserved for phone use   (blue)
Reserved for phone use   (white-blue)
Input data (-)   (green)
Reserved for phone use   (white-brown)
Reserved for phone use   (brown)

Factors affecting data transmission rate: Number of cores used, and the Type of cables
 If it is a network cable with a transmission rate of 10M and 100M, only use the core wires numbered 1, 2, 3, and 6. Among them, 1, 2 are used for sending, 3 and 6 are used for receiving; if the transmission rate reaches 1000M, the network cable needs to use 4 pairs of wires, that is, all 8 core wires are used to send and receive data.
CAT4: 10M/100M, CAT5: 100M, CAT5E: 1000M, CAT6: 10000M.

2. Different uses

Network cable T568A: used for dual-computer interconnection.
Network cable T568B: used to connect to switches or HUB and other equipment.

3. Different compatibility

Network cable T568A: Not backward compatible.
Network cable T568B: Backward compatibility.

4. The use status of T568A and T568B

the same type of equipment is connected by cross
wires, and different types of equipment are connected by parallel wires; routers and PCs belong to DTE type equipment, and switches and HUB belong to DCE type equipment. Now the wiring sequence is basically based on T568B, most of the devices are adaptive, and few devices use the 568A wiring sequence.