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post #1 of 20 Old 06-15-2013, 09:29 AM - Thread Starter
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The more I learn, the more questions I have, so thanks for putting up with me wink.gif Learning is fun.

What is the difference between T568A and T568B termination? Is there an advantage of wiring one way or the other? I know as long as you terminate both ends the same, you're fine, but what's the difference? The cable I'm looking at (see below) is ETL Verified to TIA-568-B.2. Is that the same thing as the T568B termination.

I also found Cat-5e cable at Home Depot. It's listed as 24AWG 4 Pair Indoor-Outdoor cable (Cerrowire 270-0184C). For just extending my ethernet from router to gigbit switch I'm sure it will be fine. It has a flame-retardant PVC jacket so it should be fine for in-wall installation. It comes with an electrical performance spec sheet but I don't even pretend to understand what it all means or what I should be looking for. It gives values (ACR, PS-NEXT, etc) up to 250MHz for engineering information only but some of the specs go up to 400MHz. It's about $20 for a 100' box.
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post #2 of 20 Old 06-17-2013, 12:29 PM
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Otto - are you planning to use the cable/termination for HDMI or for use with a regular IP network?

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post #3 of 20 Old 06-17-2013, 12:59 PM
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Quote:
Originally Posted by Otto Pylot View Post

What is the difference between T568A and T568B termination?
Pairs 3 and 4 are switched. When the geniuses that dreamed up TIA/EIA-568 decided on how to terminate the cables, they came up with what is now called T568A without considering what was already in common use, which is strange considering they picked connectors originated by Ma Bell. Ma Bell already had ATT 258A to do the same thing. So, the geniuses added it as T568B. T568B is most common in USA because of Ma Bell. US government requires T568A.
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Is there an advantage of wiring one way or the other?
No, not for ethernet or HDBaseT.
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...TIA-568-B.2. Is that the same thing as the T568B termination.
No, TIA/EIA-568 is a specification for all aspects of telecommunications cabling systems. T568B is a specification for cable termination.
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...Cat-5e...for just extending my ethernet from router to gigbit switch....
1000baseT ethernet was designed to work on Cat 5 cable. Cat 6 is what is usually used to wire it because it is specifically designed for the requirements of gigabit ethernet. Cat 5e should be fine if your runs are 150' or less. Why not use Cat 6? It doesn't cost much more.
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post #4 of 20 Old 06-17-2013, 01:05 PM
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Generally speaking, the most common termination I have seen within a home is 568B. The standards which the cable complies to are a complete set of guidelines which do not have any direct meaning to the termination type you use (568A or 568B).

According to the specifications link, they are a solid core cable which is good.

http://www.homedepot.com/catalog/pdfImages/61/61a287c8-b129-42d6-9548-497acc96ba05.pdf

Not sure if it is CL2/CL3 rated for in-wall use, so I would look for that specification, but I would expect it would be. Double check on that.

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post #5 of 20 Old 06-17-2013, 01:38 PM
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Not sure if it is CL2/CL3 rated for in-wall use...
It is rated CMX, which is fine. FWIW most solid core network cable is rated CM, CMX, CMR, or CMP because it is intended to go in walls and ceilings.
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post #6 of 20 Old 06-17-2013, 02:07 PM - Thread Starter
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Originally Posted by Joe Fernand View Post

Otto - are you planning to use the cable/termination for HDMI or for use with a regular IP network?

Joe

Just a regular network. I'm just extending my ethernet connection - gigabit switch in the media console (fancy name for the cabinet that holds the tv, avr, etc) to the router in another room.
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post #7 of 20 Old 06-17-2013, 02:15 PM - Thread Starter
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Originally Posted by Colm View Post

Cat 6 is what is usually used to wire it because it is specifically designed for the requirements of gigabit ethernet. Cat 5e should be fine if your runs are 150' or less. Why not use Cat 6? It doesn't cost much more.

My run will only be about 60'. I keep vacillating between 5e and 6. I only need a 100' spool and the 5e that I referenced above is around $20. I used about 80' of 5e for my security cams to my router and that works well for live viewing so I figured it would be good enough for extending the ethernet connection to the family room where the HTS is. If I never plan on using the new connection for anything other than extending my ethernet connection to hardwire by AppleTV2 and blu-ray player wouldn't 5e be good enough? So much still to learn smile.gif
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post #8 of 20 Old 06-17-2013, 04:48 PM
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AFAIK the Apple TV2 supports only 10/100 ethernet, as do most BD players. So the connection through the switch will be at best 100 Mbps and Cat 5e will be fine.
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post #9 of 20 Old 06-17-2013, 06:25 PM - Thread Starter
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AFAIK the Apple TV2 supports only 10/100 ethernet, as do most BD players. So the connection through the switch will be at best 100 Mbps and Cat 5e will be fine.

That's what I figured. My router is gigabit capable but my devices (blu-ray/ATV2) are 10/100 so it should have plenty enough speed to stream thru those devices. If those devices are replaced someday with gigabit capable devices, what then? Realistically speaking, I can connect via WiFi now at about 15-16 Mbps sustained but after the remodel I'm concerned that there'll be interference, hence the hardwiring. I've never had any problems connecting via WiFi and the subsequent streaming to my tv so isn't all of that extra speed capability just an overkill for my simple network, or am I misunderstanding something?
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post #10 of 20 Old 06-17-2013, 10:06 PM
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Unless you have gigabit devices on both ends of a connection you aren't going to run at gigabit speeds. BD and Netflix don't require anywhere near gigabit speeds. And if you do need gigabit speeds, Cat 5e should be adequate for 60', but there are no guarantees.
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post #11 of 20 Old 06-17-2013, 10:41 PM - Thread Starter
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^^^ thanks. Ya know what? I'm just going to install Cat-6 and be done with it. Now I just need to find a 100' box that's in-wall rated and I'm good.
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post #12 of 20 Old 06-17-2013, 11:28 PM
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Shouldn't be a problem. I don't think I have ever seen solid core Cat 6 cable that didn't have a CM, CMX, CMR or CMP rating.
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post #13 of 20 Old 06-18-2013, 06:58 AM
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Quote:
Originally Posted by Colm View Post

It is rated CMX, which is fine. FWIW most solid core network cable is rated CM, CMX, CMR, or CMP because it is intended to go in walls and ceilings.
Could you clarify what this means?

"General Purpose (CM, CMG, CMx) Cable

Will burn and partially self extinguish. Not for use between build floors or in air plenum spaces. Often these cables are used for workstation cables and patch cords. Complies with UL-1581 testing."

The way I read it on a CMx cable is that it is not intended to go between floors in a build out because it may not self-extinguish or it may allow fire a pathway to travel upward between floors.

I have always looked at the CL2/CL3 rating before now, so this is new to me, and I would expect to the original poster, but I have heard of 'riser rated' cabling or being in wall as well as plenum rated - which apparently carry the CMR and CMP cable ratings. But, the CM, CMx, and CMG ratings seem to indicate that while it may be fine for in-wall use, it is not appropriate (legal?) for use above a ceiling or for carrying a signal between floors.

If you have some good insight on these ratings, it would be great. Thanks.

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post #14 of 20 Old 06-18-2013, 01:09 PM
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There are lots of different low voltage cable types. CL2 and CL3 are intended for Class 2 and Class 3 electrical circuits as described in NEC Article 725. In these forums, speaker cables are the usual applications. CM is intended for communications circuits as described in NEC Article 800. The difference between CM and CMG is the flammability test and AFAIK they are interchangeable.CM can be substituted for CL2 and CL3, but not vice versa. CM can be used anywhere except in a riser or plenum in a commercial building. CMX can be used anywhere in a residence, but not in a commercial building. CMR is intended for use in risers in commercial construction and can be used anywhere except in a plenum in a commercial building. A riser is not the same as a wall. CMP is intended for use in a plenums and can be used anywhere. A plenum is a space designed to function as a return for environmental air. A normal ceiling is not a plenum, neither is a dropped ceiling unless the space between it and the real ceiling is used as a return.

Here is a substitution chart.

If you want to carry only one box of UTP in your truck make it CMP rated Category 6.
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post #15 of 20 Old 06-18-2013, 01:54 PM - Thread Starter
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^^^^ bueno!
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post #16 of 20 Old 06-18-2013, 05:41 PM
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Originally Posted by Colm View Post

There are lots of different low voltage cable types. CL2 and CL3 are intended for Class 2 and Class 3 electrical circuits as described in NEC Article 725. In these forums, speaker cables are the usual applications. CM is intended for communications circuits as described in NEC Article 800. The difference between CM and CMG is the flammability test and AFAIK they are interchangeable.CM can be substituted for CL2 and CL3, but not vice versa. CM can be used anywhere except in a riser or plenum in a commercial building. CMX can be used anywhere in a residence, but not in a commercial building. CMR is intended for use in risers in commercial construction and can be used anywhere except in a plenum in a commercial building. A riser is not the same as a wall. CMP is intended for use in a plenums and can be used anywhere. A plenum is a space designed to function as a return for environmental air. A normal ceiling is not a plenum, neither is a dropped ceiling unless the space between it and the real ceiling is used as a return.

Here is a substitution chart.

If you want to carry only one box of UTP in your truck make it CMP rated Category 6.
Thanks for all that!

I really wanted to focus on the CMX as that was a term that wasn't really clear to me. I have generally used riser rated cabling for all my installations when I buy cat-x cabling. CMR I supposed, but I've always thought of it as CL2, but I haven't really paid attention. It was the distinction of CMX which threw me off, but seems to have almost no worries whatsoever in a residential installation. CMX appears to be about the lowest fire standard feasible for residential in-wall use. I did look at the Belden website and it drew some comparisons between CL2 and the CM specifications which are out there. Basically CL2 seemed to be equivalent to CMR.

Meh, as long as it is legal for use in residential, I'll tuck that info away for later.

I am fully aware of plenum requirements and buy that God awfully expensive stuff whenever I'm working in a typical commercial space as that is most common to see the space above the grid being used for air return, but occasionally I get lucky there and it's not an issue. It is truly just the CMX rating which had me confused since I had read the specification saying that it was not to be used to wire between floors. But, I suppose that is a commercial statement vs. a residential one as it does specify CMX as being fine to use in one to two family dwellings. I also saw a response from a fire fighter who was like "Who gives a damn what cable you use in a home? Your couch and carpet will put more toxins in the air than any stupid cable is even capable of." But, that's NEC for us I guess. smile.gif

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post #17 of 20 Old 06-19-2013, 11:03 AM
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Oh, I left one thing out. Although CMX is intended for residential use, it can be used in a raceway in a commercial installation.
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post #18 of 20 Old 06-19-2013, 10:33 PM - Thread Starter
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^^^^ went to a couple of big box hardware stores today and I could only find CMR solid core Cat-6 cable, 100' for about $30. That should be ok for running across the attic and down inside the walls, correct?
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post #19 of 20 Old 06-19-2013, 10:46 PM
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CMR is fine. Any of the CM ratings are fine for residential use.
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post #20 of 20 Old 06-20-2013, 10:09 AM - Thread Starter
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^^^ one more thing to check off of my list. Thanks.
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