I too think that the arguments over whether the 568A or 568B wiring configuration is better are quite pointless. If
the tighter twist patterns were going to make that much of a difference, we'd also better change the existing pin 3/6 pair over to pins 7/8 or something similar.
While we're around the twist.....
The people who say it is electrically different in terms of transmision say that because the orange pair (Which is twisted more than the others)
I've just examined the pairs on a length of Enhanced CAT5 UTP currently in my supplies and come up with the following figures for twists-per-foot:
White/blue = 32
White/orange = 19.5
White/green = 25.5
White/brown = 18
So on this cable the green pair is more tightly twisted than the orange anyhow.
As Ed says, even if this was a significant factor, swapping the positions of the W/O and W/G pairs is only going to swap the characteristics of the receive and transmit data paths anyway.
The reason for having different twist rates is to minimize crosstalk. If each pair had exactly the same twist, then where the pairs lie together in the cable you'd get places where tip of one pair is repeatedly next to tip of another pair, ring of one pair repeatedly next to ring of another pair and so on. The different twists mean that over any reasonable length of cable the coupling between any two individual conductors of different pairs in minimized.
If you are adding to an existing installation I think the most important thing is to be consistent and follow whatever method is already in use to avoid confusion. If starting from scratch, it really doesn't matter which you adopt, although personally I stick with 568B.
You will likely never see a true "RJ45" jack
I'd bet that there has never
been a true RJ45 installed in this country! And isn't RJ45 a keyed
8-position connector anyway, not the "RJ45" of present-day network connections?
The RJ numbers are probably misused even more on this side of the Atlantic, since nobody has ever heard of USOC and certainly doesn't realize that they refer to the wiring configuration, not just the physical plug/jack style.
I had a query from somebody (non technical) the other day about hooking up a laptop in European hotel rooms. She said that several places she'd contacted had told her that they provided an RJ25 jack for visitors to plug in their modems. She'd never heard of RJ25.
I'd be willing to bet that the jack is really just RJ11, but somebody in the hotel(s) concerned did a quick internet search and decided that because that "weird-looking American jack" is 6 position that it must be RJ25.