T568A or B?

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Getting ready to wire my house with ethernet. I'm a little confused about how to terminate the cables. Does it matter as long as it's the same on each end? Should it be the same for all connections (router, switch, PoE switch, computer, cameras, etc...)?

Thanks!
 

tigerwillow1

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All that matters from a technical aspect is that both ends of a cable or cable run are the same (either 568A or 568B). Based on Internet reading, it sounds like 568B is more widely used. When I've looked, every commercial patch cable I've seen uses 568B. I got started with 568A and have continued it just to keep everything the same. If you're starting from scratch, 568B sounds like the preferred way to go.
(edited to reduce ambiguity)
 
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bp2008

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All that matters from a technical aspect is that both ends of a cable or cable run are the same (either A or B).
Not quite. The twisting of the 4 pairs has a significant effect on performance. It is important that pairs be connected to pins 1&2, 3&6, 4&5, 7&8. If you were to randomly assign wires to the pins without considering where the partner wire in each pair was connected, the cable would underperform or even fail to maintain a solid link depending on the distance.

Based on Internet reading, it sounds like 568B is more widely used.
Yes, it is by far the most common ethernet wiring standard.
 

TonyR

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Not quite. The twisting of the 4 pairs has a significant effect on performance. It is important that pairs be connected to pins 1&2, 3&6, 4&5, 7&8. If you were to randomly assign wires to the pins without considering where the partner wire in each pair was connected, the cable would underperform or even fail to maintain a solid link depending on the distance.
I think that @tigerwillow1 is agreeing that it DOES matter, in a not-so-obvious way when he stated that "All that matters from a technical aspect is that both ends of a cable or cable run are the same (either A or B)"; Meaning (to me) ".......both ends T568A or both ends T568B".

Me? I'm T568B all the way.
 

bp2008

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I think that @tigerwillow1 is agreeing that it DOES matter, in a not-so-obvious way when he stated that "All that matters from a technical aspect is that both ends of a cable or cable run are the same (either A or B)"; Meaning (to me) ".......both ends T568A or both ends T568B".
True!
 

tigerwillow1

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I changed post #3 to state the wiring choices more explicitly. I'm don't want add even more confusion to the world!

I've read all sorts of bogus info on various web pages, like commercial installations should use 568A and residential 568B, then just the opposite somewhere else, that 568A is more compatible with other standards, and that 568B is more compatible with other standards. The best one was that once a signal is on one color of wire it won't work on a different color wire. There are some claims that if you mix 568A and 568B segments on the same run there will be signal degradation. Intuitively, I'm skeptical, but have no means to prove or disprove it.
 

copex

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The final answer is to stick with the 568B standard on all ethernet cables you make.
now i would say it makes no difference as long as both sides are the same :)

Which for the most part, has gone the way of the dodo bird.
yes most network cards / switches support Auto-MDIX / autosencing, but not all so the dodo bird is not dead yet LOL
 

Dave88LX

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I started making Ethernet cables in 1999. I've done it for various gov't facilities, military bases, and commercial companies. I've never seen any location or person using the 568A standard.

I've heard something along the lines of 568A was compatible with older USOC wiring, and 568B was the "new" (at the time) AT&T standard, and what everyone was using.

In short: Nobody uses 568A. Use 568B.
 

tigerwillow1

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I started making Ethernet cables in 1999. I've done it for various gov't facilities, military bases, and commercial companies. I've never seen any location or person using the 568A standard.
Wow, that means there is a lot of false information on the Internet. There are a lot of sites that say 568A is required for any work done under a federal contract. Here are 3 of many examples:
The Difference Between the TIA/EIA T568A and T568B Wiring Standards
TIA standards, testing Category 5, T568A versus T568B
What is the difference between T568A & T568B?
 

anijet

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Dave88LX

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Wow, that means there is a lot of false information on the Internet. There are a lot of sites that say 568A is required for any work done under a federal contract. Here are 3 of many examples:
The Difference Between the TIA/EIA T568A and T568B Wiring Standards
TIA standards, testing Category 5, T568A versus T568B
What is the difference between T568A & T568B?
Federal contracts are written by people who have no flippin' clue what they are talking about.:smash: (OK that might be an over-generalization, but just my personal bias and experience talking).

I have seen while searching the same thing, that "it says to use 568A for federal contract work", but, I personally have not seen it executed (not to say it doesn't exist, it's a very very big fed).

I just had to piece together parts for a "standalone/shielded" network installation because "they" worded the contract wrong, and that portion of the network project was never installed. Half the parts I was given were not correct either. Unshielded patch panel for a shielded network. Wall boxes not deep enough or large enough to accept the Keystone jacks, crappy connectors etc.

"Just make it work if you can make it work, I will accept responsibility" is what I was told by the project mgmt. Keystone jacks are smashed up against the back of the wall boxes, bent up at 90* angles. Barely holding onto the edges of the faceplates, trying to keep from popping out. The one thing I would not budge on is terminating it down to the unshielded patch panel. "Good enough for government work" is not just a saying unfortunately. :(

All that to say just use 568B. Dang near anything you run across is going to be wired 568B, to include any pre-terminated cables you buy (yes you can run A-A with B-B, but still).
 
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