T568A and T568B

[chandra_rc16]

Hi All,

I know that these two are the wiring shemes for the utp cables for connecting to rj45 connector.

Actually if we connect both the ends in either T568A OR T568B, then it is called as a straight through cable.

And if we connect one end as T568A and other end asT568B, then it is called as a crossover cable.

My questions:

1. Even though we don't follow the schemes mentioned in above standards, we can create the straight through and crossover cables, then what is the acutal purpose of defining the pin/pair assignments?

2. I don't see any big difference between A and B, we just swap the pair2 and 3. What is the real intention for inventing the T568B standard though we had T568A.

Can someone please explain me in detail?

Or a appropriate doc or link is fine.

Thanks in advance.

Regards,
Chandu       

[acampbell]

Chandu,

Have a look here:-

http://en.wikipedia.org/wiki/TIA/EIA-568-B

There are many other links from that page too

It is very important that you keep to the TIA/EIA standards.

If you do not you will encounter issues caused by induction/overhearing between the

required pairs

Regards,
Alex.
Please rate useful posts.

[chandra_rc16]

Hi Alex,

I already gone through the link but i didn't found the exact explanation for thisquestion

2.  I don't see any big difference between A and B, we just swap the pair2  and 3. What is the real intention for inventing the T568B standard  though we had T568A.

Regards,
Chandu

[dominic.caron]

Some people were still using the old AT&T standard, T568B only make it an official standard.