Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer
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I always use Standard B since started in this field.
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@melvinsilva said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
I always use Standard B since started in this field.
We use Standard A when we have done our own wiring. It actually has just the tiniest bit better signaling. B was designed to be slightly easier to deal with. They are essentially interchangeable, but there is a reason that A was designed to be the standard first.
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@scottalanmiller said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
It actually has just the tiniest bit better signaling.
Bullshit. A twisted pair is a twisted pair.
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@scottalanmiller said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
They are essentially interchangeable,
They are 100% interchangeable.
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@scottalanmiller said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
but there is a reason that A was designed to be the standard first
The TIA T568B standard is the most widely used standard, and is also backwards compatible, for 2 pairs, with the older AT&T 568A standard.
The US government mandates the T568A standard in all government contracts. That is the only location I know of to use A as the standard.
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@JaredBusch said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
@scottalanmiller said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
It actually has just the tiniest bit better signaling.
Bullshit. A twisted pair is a twisted pair.
Not exactly. The number of twist per length is different on different pairs in the same cable. It's made so on purpose. Tighter twists are better and depending on the wiring standard you use and the cable, you are using different pairs for different signals. So there is a difference. That said, I'm sure it doesn't make any difference in the real world as cables have to fulfill standards to be used.
According to the standard (latest being ANSI/TIA-568-D.2), T568A is the standard and T568B is called the optional wiring to be used "if necessary to accommodate certain cabling systems". As you said T586B was made to be compatible with AT&T telephone wiring. And that is the only reason it exists.
So if one follows the standard to the letter (as the government does) one should use T568A.
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@Pete-S said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
The number of twist per length is different on different pairs in the same cable.
Unless you are choosing to be @scottalanmiller now, it does not matter.
The exact TPI difference between pairs is super fractional. It varies to prevent crosstalk. If not for that, they would all be twisted as much as possible for the best throughput.
Additionally, 1000base-t sends data out all 4 pairs simultaneously. SO it is imposible to have a single pair be "faster" than the others. Yes, the pair with more twists will deliver the 2 bits slightly ahead of the other 3 pairs. but it does not matter as nothing will be done until all 8 bits have arrived.
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@JaredBusch said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
@scottalanmiller said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
but there is a reason that A was designed to be the standard first
The TIA T568B standard is the most widely used standard, and is also backwards compatible, for 2 pairs, with the older AT&T 568A standard.
The US government mandates the T568A standard in all government contracts. That is the only location I know of to use A as the standard.
Yes, B is by far the most commonly used. But A came first and was designed as such for the absolute best performance. The question should not matter as to which is more common, only "why would you ever choose the less ideal option if there is no benefit?" In most of the world, backwards compatibility with pre-data telephone lines is something we've not had to consider for literally decades.
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@scottalanmiller said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
designed as such for the absolute best performance.
This is not true, no matter how many times you say it.
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@JaredBusch said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
@scottalanmiller said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
designed as such for the absolute best performance.
This is not true, no matter how many times you say it.
Actually it is true, we just both have it backwards. A is the backwards compatible one, B has the superior signaling.
https://www.doitforme.solutions/blog/ethernet-wiring-t568a-versus-t568b/
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@scottalanmiller Thats why since I started working in Network, used Standard B.
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@scottalanmiller said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
@JaredBusch said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
@scottalanmiller said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
designed as such for the absolute best performance.
This is not true, no matter how many times you say it.
Actually it is true, we just both have it backwards. A is the backwards compatible one, B has the superior signaling.
https://www.doitforme.solutions/blog/ethernet-wiring-t568a-versus-t568b/
So I actually bothered to read that to see your proof.
There is no proof in there.
And that backwards compatibility statement in that document contradicts everything else out there.
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Ok so I did some looking to refresh memory.
Telco was blue (red/green) and then orange (yellow/black) for a 2 line phone. I did this a lot back in the 90's when I worked with alarm systems.
That matches to T568A. So your link has that correct (but still with no proof).
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It's so old now. First standard is from 1991. I remember that in those days we considered using twisted pair for networking dubious practice. You'd run coax for ethernet and twisted pair for phones if you were going to do it right.
But just a few years later twisted pair was the only thing worth using. Especially when 100 Mbit became available. And in those days being able to run the same wiring for phones and for the network was a big deal for a big office.
From what I can gather T568A is two pair USOC compatible but T568B AT&T 258A color code and one pair USOC compatible. But POTS was never big on the 8-pin RJ45, only 6-pin RJ11. ISDN which is digital used 8pins and T568A wiring but that never became as popular in the US as the rest of the world.
So T568B ended up being the most common in North America because it followed the older 258A color code while T568A was the most common in Europe and elsewhere and in US government buildings due to the standard.
But in 2020 none of that matters. Forget about POTS, heck, even VOIP is circling the drain. I've seen big multinational corporations moving to cell phone only with PBX as a service for all employees just as many offices are becoming wifi only.
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@Pete-S said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
But just a few years later
"Few Years"
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@Pete-S said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
I've seen big multinational corporations moving to cell phone only with PBX as a service for all employees just as many offices are becoming wifi only.
I've seen no legit company consider this. Cell phone service in the US is poor (we have a lot of open space and really bad regulations), and you can really hear the quality issues when you do it. And people don't like the company controlling access to their personal space.
Someone, somewhere has definitely tried this. But the only thing we see anywhere is people moving to VoIP, and often using their mobile devices as yet another VoIP end point.
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@scottalanmiller said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
@Pete-S said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
But just a few years later
"Few Years"
Haha! Well, I was writing from memory. It felt like a few years, might have been 10 though.
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@Pete-S said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
Haha! Well, I was writing from memory. It felt like a few years, might have been 10 though.
Twisted pair was getting big by like 1999. Not quite ten years, but more than a few
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@scottalanmiller said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
@Pete-S said in Copper Termination Standards - CompTIA Network+ N10-007 Prof. Messer:
I've seen big multinational corporations moving to cell phone only with PBX as a service for all employees just as many offices are becoming wifi only.
I've seen no legit company consider this. Cell phone service in the US is poor (we have a lot of open space and really bad regulations), and you can really hear the quality issues when you do it. And people don't like the company controlling access to their personal space.
Someone, somewhere has definitely tried this. But the only thing we see anywhere is people moving to VoIP, and often using their mobile devices as yet another VoIP end point.
You'll see it soon enough. Quality is not part of the equation, only cost and convenience.
It's like blu-ray versus netflix, CD versus Spotify etc. Quality never wins...
