cat5e/6 wiring - T568A or T568B ?

[bebster]

Have to pull the trigger on a wiring standard for my project.

I realize that the important aspect is that both ends of a cable

are wired the same way, and the same standard is used throughout

the project.

Seems that T568B is by the most commonly used on components

being sold in the industry, and is most favored.

I'm curious what standard (T568A or T568B) others are using?

[thecodeman]

568b, personally.

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[PeterM1]

Have to pull the trigger on a wiring standard for my project.

I realize that the important aspect is that both ends of a cable

are wired the same way, and the same standard is used throughout

the project.

Seems that T568B is by the most commonly used on components

being sold in the industry, and is most favored.

I'm curious what standard (T568A or T568B) others are using?

It doesn't really matter, as long as you pick one and you stick with it for your entire installation. For the components that are wired for the "other" one, as long as you understand the 2 different pairs that are changed between A & B, you can easily cross-connect them to your standard.

[jberger]

The main difference in wiring standards involves the use of rj45 jacks as telephone outlets.

568a allows for telephones to use 2 lines in a standard rj45 jack, where as 568b allows only 1 line to be used for phone because the pairs are split for lines 2 and 3.

As long at the entire structure is wired for all A or all B, it will not matter unless you need phone service on the same wiring structure. ]

The recommend CEA2030 wiring standard is that the wire shall meet 568b specifications and pinned to 568A outlet standards. This standard is also being adopted by CEDIA upon release of the revised standard.

[thecodeman]

The recommend CEA2030 wiring standard is that the wire shall meet 568b specifications and pinned to 568A outlet standards. This standard is also being adopted by CEDIA upon release of the revised standard.

So, the wall jacks will be A, while the wiring is B? Is that right? If that's the case, I'd rather wire everything A.

[henniae]

The recommend CEA2030 wiring standard is that the wire shall meet 568b specifications and pinned to 568A outlet standards. This standard is also being adopted by CEDIA upon release of the revised standard.

So' date=' the wall jacks will be A, while the wiring is B? Is that right? If that's the case, I'd rather wire everything A.[/quote']

The difference between 658A and 658B is more than just what colors are terminated in which positions on the jack. B also includes electrical characteristics of the wire and connectors as well as many other things. If the physical wire is rated as compliant to 568B you can still terminate the ends as 568A. The reason for terminating as 568A is so that the blue pair (a.k.a. pair #1) as used on pins 4 & 5 and the orange pair (a.k.a. pair #2) are used on pins 3 & 6. If the wire were ever to be used for analog phones than the blue pair is standard as phone line #1 and the orange pair is standard as line #2.

[thecodeman]

The recommend CEA2030 wiring standard is that the wire shall meet 568b specifications and pinned to 568A outlet standards. This standard is also being adopted by CEDIA upon release of the revised standard.

So' date=' the wall jacks will be A, while the wiring is B? Is that right? If that's the case, I'd rather wire everything A.[/quote']

The difference between 658A and 658B is more than just what colors are terminated in which positions on the jack. B also includes electrical characteristics of the wire and connectors as well as many other things. If the physical wire is rated as compliant to 568B you can still terminate the ends as 568A. The reason for terminating as 568A is so that the blue pair (a.k.a. pair #1) as used on pins 4 & 5 and the orange pair (a.k.a. pair #2) are used on pins 3 & 6. If the wire were ever to be used for analog phones than the blue pair is standard as phone line #1 and the orange pair is standard as line #2.

I understand the advantage to wiring B for analog telephony, but for consistency, why would you terminate the ends to A?

[henniae]

I understand the advantage to wiring B for analog telephony, but for consistency, why would you terminate the ends to A?

A picture will help.

The standard for POTS phones is to use the blue pair for line 1 and the orange pair for line 2. 568A puts the blue and orange pair in the correct locations on the jacks so that an analog phone with an RJ12 jack can use the orange and blue pair.

If you never use analog phones with a line 1 and a line 2 then you can just use 568B.

[bebster]

If you did wire with 568B, wouldn't the 2 phone line signals still run on the center 4 pins, namely the blue and green wires under "B". Unless I'm missing something, seems like the only difference then would be the telephone signal travels over wires that are green and not orange, but that electrically it should work the same, and therefore lines 1 & 2 on a POTS phone would work with either scheme.

[PeterM1]

I understand the advantage to wiring B for analog telephony' date=' but for consistency, why would you terminate the ends to A?[/quote']

A picture will help.

The standard for POTS phones is to use the blue pair for line 1 and the orange pair for line 2. 568A puts the blue and orange pair in the correct locations on the jacks so that an analog phone with an RJ12 jack can use the orange and blue pair.

If you never use analog phones with a line 1 and a line 2 then you can just use 568B.

Agreed, although this isn't (shouldn't be....) an applicable combination anymore. The cable will be either supporting analog lines (and as you said it should be wired as or it will be wired for networking (either A or B will work) but not both. Gigabit ethernet requires all 4 pairs on a CAT-[5|5e|6] and even in the old days of 10/100Mbit requiring 2 pairs only, I'd still run a separate CAT5 for the 2 analog lines. My 2c.

[thecodeman]

Agreed, although this isn't (shouldn't be....) an applicable combination anymore. The cable will be either supporting analog lines (and as you said it should be wired as or it will be wired for networking (either A or B will work) but not both. Gigabit ethernet requires all 4 pairs on a CAT-[5|5e|6] and even in the old days of 10/100Mbit requiring 2 pairs only, I'd still run a separate CAT5 for the 2 analog lines. My 2c.

Yeah, that's the way I wired it in my house (everything b-spec and a separate jack for phone) but I was just curious to the benefit of a spec wall plates and b spec patch cabling.

[jberger]

henniae said it better than I, B Spec includes the technical specification for the installation, but A is still the preferred residential wiring standard. This standard makes the wiring more flexible, not less.

A will remain the recommended standard for residential in the next revision.

The inclusion of A for residential makes sense because all jacks are wired the same, so only the cross connects in the can need to move when moving a telephone jack over to ethernet. Makes it easier for the installer and the homeowner in both the short and long term.

No one is recommending you steal pairs for telephone and ethernet from the same jacket, other than in situations where a retrofit isn't feasible.