atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring 568a configuration

I had an install in a hotel a few years back for a franchise that required two line phones in every room. The electrical contractor terminated all the in room wiring on 8P/8C jacks using 568B. Connecting the second line, we had to connect the jumpers onto the green pair (typically line three). Yes, USOC is needed if using three or four line analog phones or you would be splitting the pairs.


Auto sensing network equipment doesn't do anything with a cable run terminated A with a B patch cord (or vice versa) Use a cable tester and and test from an A patch cord to a cable run terminated A and a B patch cable at the remote end, it will show as a straight thru cable run. Now remove the B patch cord and replace with a crossover cable (one end A, other end B) and you'll see the orange and green pairs flipped - this is where the auto-sensing kicks in. Before auto-sensing, had to use cross over cables when connecting switch to switch, etc.

Computers will work on two pairs if needed. They only use pins 1, 2, 3 and 6. Now granted, it's not ideal and will definitely fail any cable test and not recommended but have done it in situations where there is one cable run and customer wants a phone and computer and running a second cable is not an option.

I don't specifically order A or B patch cords, I order the length and colour I need and use whatever I receive. Trust me, the A patch cords are computer patch cords - Cat 5E and Cat 6 rated.

"Looking at that, fiber has to be cheaper and easier."

-Hal
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Fiber is cheaper - the electronics are not.

Prices for fibre network cards and switches are astronomical (at least the last time I looked).

Sam

I have never in my life seen a prefabricated computer patch cord that was terminated on both ends with 568A. If I bought such a cord, I would return it because whoever made it did not know what they were doing, in my opinion.

You also need to check the markings on the outside of the cable to make sure it is of the appropriate construction. If it is not stranded and marked for IEEE category (3, 5x or 6x) and UL type (CM, CMR, CMP etc.) return it. Unless you like to work overtime for free diagnosing unexplained problems.

Everybody is talking about CAT7 here in the states and it doesn't even exist here as TIA skipped the CAT 7 designation. CAT 7 is an ISO standard that is also called Class F.

I just don't get it as to why people don't understand that there are two standard bodies. The TIA in the states and ISO for Europe and most of the other countries

Why would the it guy say it doesn't work? He can say he doesn't like it...or whatever but if the cabling is A on both ends..workstation and patchpanel then it is no different transmission wise from B, just transposed pairs. Makes no sense. The guy wouldn't know the difference unless he looked at how it is terminated.

I think he had a bad patch cord or a bad switch because he declared "nothing works since you rewired it" Then proceeded to open up the jacks as well as check the patch panel.

Butch Cassidy - now you've seen a 568A patch cord. Not Chinese crap. From Belden, a reputable manufacturer.




Someone does or uses something different from what you're used to and its wrong? I think in my past 20+ years in doing this, I've replaced only a handful of patch cords, and most of those were ones under desks that people were rolling their chairs across,,, and those were not done on overtime or for free.

Thanks for the closeup of the cable printing. I can see that it is CMR 24 AWG stranded. I suspect this is category 5a because it is using 24 AWG wire not the thicker 23 AWG wire required for Cat 6x.
It says "Gigaflex" but I believe 5a is rated for gigabit ethernet. So far so good.

I can't see the colors in the plugs. Can you turn the plugs over and take a picture from the side without the tabs? From what I can see, it looks like white-orange orange white-blue blue white-green green white-brown brown. That would make it category "amateur".

By the way the wire is marked Belden, but that does not mean Belden made the whole cable including the terminations. This might be a homemade cable.

Wow, a homemade cable, really??? Part number is AX350002 (now updated to C501106004) - check it out on Anixter, Graybar, etc.

Cable is labeled: Belden Gigaflex PS5 Modular Cord --4PR/24 Stranded E108998-S C(UL)US CMR -- Verified (UL) Cat 5E -- ROHS 14002

Remember, from this side, for pins 1 to 8, you are looking at it right to left which is White/Green, Green/White, White/Orange, Blue/White, White/Blue, Orange/White, White/Brown, Brown/White - AKA 568A. In the picture you can see the orange wire crossing over to the 6th pin. You cannot see the colours from the other side due to the manufacturing.

Although the Cat 7 cable is an ISO/IEC 11801 wiring standard for 10 Gb/s over a maximum of 100 m, the IEEE, which develops ALL USA wiring standards has concluded a Cat 8 standards study within the P802.3bq Task Force. This work was concluded on June 30, 2016. The Cat 8 cable standard outlines the transmission of 25 Gb/s and 40 Gb/s data over ethernet using copper cable. Click Here

The IEEE sets the technical standards for the ANSI TIA/EIA to implement in structured wiring proforma, known as 5xx, 6xx and 7xx (such as TIA/EIA 568A or 568B wiring). At this time, I don't know the TIA group which will publish the TIA/EIA standards for Cat 8.

If you thought the specifications for ISO/IEC Cat 7 standards were tough, read the standards which have been adopted by IEEE SA for Cat 8.

Rcaman