atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring cat 3 or cat 6

OK, the question is-
Why not use cat 6 instead of cat 3 for a phone line?

Before you guys pound me let me 'splain-

I read a lot here and there are many that advocate cat 3 for phone. The CGs are taken to task for using cat5/6 for everything. Where I work they pull cat 6 for everything, but they say that is due to IP style phones(CGs run the show here, but the 'phone guy' has a telco background). Is the cat 3/POTS VS cat 6 issue something that is related primarily to residential? Is it mainly a code thing for some of you?

I would just like to see the comments because I like to learn, and I have a decision to make shortly-I have a pile of cat 6 that is no cost to me, or do I go and purchase a roll of cat 3 to run for a few POTS drops?

Thanks guys, you all have a really nice community here.

It's simple. Anything higher rated than CAT 3 for voice is a waste of time and money. Just tell them two CAT 3's trump one CAT 6.

If you're wiring for a full IP system than yes CAT 5 or 6 is required per spec.

I think he's talking about using left over Cat6 from his job to run drops in his house. Hey if it's free and it's long enough why not. If you have to buy it, Cat3 is fine.

The guys here like Cat3 for phones because it is easier to untwist and punch down on 66 blocks. Which is true.

They prefer 66 blocks to 110 because it is easier to attach butt sets and toners to 66 style clips. Which is true also.

Most system installation manuals recommend using 66 blocks. The ones I've read anyway.

Cat3 is cheaper than Cat5 or Cat6.

That's my 2c anyway.

Where I work they pull cat 6 for everything, but they say that is due to IP style phones

Maybe those CGs should learn to read something other than computer magazines. Most IP phones will work just fine with CAT3. No high bandwidth data transfers going on there. However if they are going to install it like data, terminated on a patch panel and 8P/8C 568 jacks on the walls they might as well just make everything the same. But that's not to condone using patch panels and 8P/8C jacks for voice.

From a telco standpoint we require a greater flexibility in utilizing the individual pairs of a cable. With data it's a given that all four pairs of a cable will originate from a 4 pair jack on a patch panel and run without interruption to a 4 pair jack on the wall.

In telecom we often need to use the pairs individually. One pair on a cable might be used for a phone with another for a fax machine or even another phone. There could be two and even more 6P/4C USOC jacks on a wall plate all fed from the one four pair cable. Back at the other end the cables terminate on a cross connect consisting of usually 66 blocks. There the individual pairs of each cable are readily available to be used as necessary, and can be easily connected and reconnected with jumpers to other 66 blocks as additional equipment is added or removed. Hence the name "cross connect".

Getting to the CAT3 vs CAT5/6 issue. As has been pointed out CAT5/6 is not needed for most telecom installations. There is a great cost savings with using CAT3 especially over CAT6 and especially if a plenum listed cable is needed. Also consider the higher cost of terminating CAT5/6 on 66 blocks due to the preparation of the cable with it's tight twists.

So if it were me I would go out and buy a box of CAT3 for a few bucks and throw that CAT6 in the scrap pile.

-Hal

If you have CAT6 at no cost to you run the CAT6. Why spend the money for CAT3 when you don't need to. If needed you can split the pair out of the CAT6 for other analog devices. If you are going to connect a ethernet device (PC) to the phone then use CAT6.

If you have CAT6 at no cost to you run the CAT6. Why spend the money for CAT3 when you don't need to.

Because CAT6 is not worth the trouble.

-Hal

"Why not use cat 6 instead of cat 3 for a phone line?"

~ Cat6 costs more than Cat3, especially in plenum.
~ Cat6 is more time intensive to punch down than Cat3, especially if it's 23ga or bonded pairs.
~ Cat6 is heavier and bulkier than Cat3, which means putting less of it on my truck and more effort hauling it up to the xth floor of a building.
~ Cat6 has a significantly larger OD than Cat3, which can present problems if the job is in conduit.

Without fail, every single commercial job I do that specs cat6 for telephone goes something like this: all cabling is to be Cat6, on Cat6 rated 110 blocks (more $$$), using Cat6 jumper wire (still more $$$), but terminated on an RJ11 wallplate (one pair) and connected from the IDFs to MDF using Cat3 25/50/100pr. :bang: :bang:

Most of that is n/a in a residence, but I still don't see the point in using cat6 for voice. Look at the cable coming into your NID - it's not cat6, it's cat-nothing. 50 or 100' of Cat6 past that will do nothing to improve the quality of service, and thus, is a waste.

Jack

If I didn't have to pay for it, I would use the Cat 6 - if I had enough of it to wire for Data too, while I was wiring for Voice.

Sam

Analog phones can run on about any 2 conductor cable.

VoIP needs data cables which should be Cat 5 or 6


Digital phones need 1 twisted pair which can be Cat 3, 5 or 6. Many digital phones are fussy about the length of wire so if you use Cat 5 or 6 then you can't run as long of cables because of the extra twisting makes the conductors longer. then the wire itself. Also a big problem is if you use a Cat 5 or Cat 6 backbone with 8p jacks and plug a regular 6p phone plug in it will work but you have no side support. If the phone cord is tripped over or pulled very hard it will twist in the jack and bend the pins causing problems.

cat 3 would be my first choice

if I didn't have 3 and it wasn't a lot of runs I would and do use 5/6 .

VoIP needs data cables which should be Cat 5 or 6

That's not exactly true. The IPO, which I am somewhat familiar with, can use CAT3 as a minimum requirement. However the topology is the same as for data, with 4 pairs end to end and 8P/8C jacks and a patch panel. So you might as well run whatever you are using for data because it makes no sense to mess with two different cable types.

-Hal

Thanks for all the comments. I will pull the cat 6 and get someone that is skilled at it to terminate. I have plenty for my short runs, it amazes me when I see how much is wasted on some jobs.

My favorite comment is from Fletcher-


'...it's not cat6, it's cat-nothing.' : )

Thanks 7echo - I wish I could claim the phrase, but it's not mine. And I do agree with Silversam and Skip about using what you've got, especially on a small scale.

BTW, welcome to the forum.

Jack

Everyone here can argue about the merits of cat6 vs. cat3 all day long but if it the cat6 is free then use it. No reason to spend money when you have free cable to use.

Just felt like adding a few more cents. Cat3 and cat5 are not recognized cabling types by the TIA/EIA for those on here who want to things "by the book". Cat5e and up is the minimum recommended cable type. Second the main reason for using cat5e and up at each location is for flexibility and not because of some mysterious property that cat6 possesses over cat3. Its obviously a lot simpler to replace a jack than to replace a cable run if you needed to convert a voice cable to data.

First, when I say CAT5 I am refering to all the other iterations for data such as 5e, 6, 6e, 7, ad nausium. I'm tired of spelling them out.

Second, it's simpler to only replace a jack ASSUMING that the other end of the cable terminates on a patch panel with the data patch panel. If I have anything to do with an installation the phone system won't even be in the same room and the voice cable runs will be punched down on 66 blocks. So does the EIA/TIA also specify where I locate my system and how I terminate my cables?

That's why that's not the "book" I'm interested in reading.

-Hal

Actually yes there are guidelines and best practices for ER and TR design. I also misspoke and its just CAT5 that’s no longer recognized and not CAT3 in 568-C. I’m curious as to why people in the industry would recommend installing cable that does not even meet established standards and recommendations for commercial and residential installations. How can we criticize sparky and anybody else who decides to string a cable from point A to point B when we can’t even agree amongst ourselves on how to do things? Yes we all know CAT3 will handle voice just fine but that’s not the point here. What standard are we to be held to? Some of us follow TIA/EIA standards and then some of us decide their way is better so screw the standards. There are documents and guidelines put together by TIA/EIA and BICSI that are widely recognized as the “way” of doing things and whether you agree with it or not those are the rules. A person can go off and do their own thing but doesn’t that make them the same as the CG, Sparky, novice, idiot, or whatever else you want to call them?

Doesn't the TIA/EIA standard say that only one of the cables in a work area outlet need to be cat5e or better? I think that the standard allows cat3 as long as there is also higher grade cables for data. However, I could very easily be wrong.

The system that I manage employs multiple cat6 runs for data and a cat3 run for voice in each outlet box. I have always believed that this is allowable under the TIA/EIA 568 standard. Please correct me if I am wrong. Still, why adhere to a TIA/EIA standard and ignore years of telecom experience? The standard is only a recommendation.

-Nelson

We have bounced this issue back and forth for years. Both sides have valid points, however it is important to note that TIA/EIA standards are not requirements. In a perfect world, these standards would be enforced by local code enforcement personnel (AHJ), similar to the National Electrical Code. That is just it; these standards are not enforced and therefore shouldn't be expected to be the "norm". At present, these standards are nothing more than recommended guidelines.

With this being said, there is nothing wrong with running CAT1 or CAT6 for voice. For those who are newer to this industry, they may not know of any other wiring material below CAT5. For those who have been in the industry for years or even decades, they know what works.

Just like painting a house, there is a perceived right way and wrong way to do it. For the time being, either way is correct.

I’m curious as to why people in the industry would recommend installing cable that does not even meet established standards and recommendations for commercial and residential installations. How can we criticize sparky and anybody else who decides to string a cable from point A to point B when we can’t even agree amongst ourselves on how to do things?

There is a big difference between an industry that has established practices and someone with little or no knowledge doing their own thing.

TIA/EIA and BICSI are held in high regard by CGs and IT "professionals" because it is the written word balanced against their zero experience. It's like learning from a text book in school (which is what they are used to) with that being their only exposure to the subject. There is your main proponent to these "standards".

I doubt that a sparkie will even know what TIA/EIA and BICSI are so you can count them out right there.

Further, TIA/EIA and BICSI are only recommendations, and they are full of inconsistancies and ridiculous requirements at that. If you have been in the telecom industry from before TIA/EIA and BICSI, you know who it was written for and by whom. You will also be capable of making judgement calls as to what part of those recommendations are legitimate.

The CAT3 vs CAT5 debate is over one of those judgement calls. It really boils down to interchangeability and my objection is that as I said above. We don't run voice wiring like we do data. If you are terminating your voice wiring on 66 blocks it will never be used for data. CAT5 is difficult to terminate on 66 block clips. CAT5 is not needed for voice. CAT3 plenum is much cheaper than plenum CAT5. NONE of this is taken into account by TIA/EIA and BICSI.

-Hal

Nogden, TIA/EIA568-B states that there should be a minimum of two communication outlets at each location with one being a minimum of CAT3 and the other being a CAT5e or higher or a multimode fiber. They still recommended though that both runs be at least CAT5e. We are now at 568-C and the recommendation is for both jacks to be a minimum of CAT5e or better and one of them can be a multimode fiber. My gripe with the years of experience thing is that everyone is different and we end up in the same boat where one guy does it one way and the other does it another way.

My gripe with the years of experience thing is that everyone is different and we end up in the same boat where one guy does it one way and the other does it another way.

And I have no problem with that as long as it is done professionally and meets the requirements of the current service it is providing. I see no reason to try and future proof as that is an impossible waste of money. Just look at those specs that want a 25 year warranty on a CAT6 installation. That's an example of the intellegence at work here. It will be in the dumpster on the way to China in 10.

-Hal

And so the old BELL SYSTEM way was the only way and a good way at that! :toothy: :toothy:

"With this being said, there is nothing wrong with running CAT1 or CAT6 for voice".

Ed, doesn't the FCC mandate a minimum of Cat3?

Future-proofing was mentioned - the only way to future-proof a building of any type is to pipe the whole thing. Sadly, many of the customers I deal with are more hung up on Cat6 and don't give a crap about conduit, which is sad - in 10 or 20 years, they will probably have obsolete/insufficient cable and no way, short of tearing the whole building apart, to replace it.

Just curious - what is the maximum data transmission speed one can get out of cat3 cable?

Jack

And so the old BELL SYSTEM way was the only way and a good way at that!

If we could just maintain the workmanship standards of those practices. It would be a major improvement over the abortions we have today that are created by the new generation of so called professionals who's diapers need changing.

-Hal

Just curious - what is the maximum data transmission speed one can get out of cat3 cable?

I believe 10Mb. 10baseT

-Hal

Just curious - what is the maximum data transmission speed one can get out of cat3 cable?

10base-t (10 Mbps) as Hal mentioned. However, there is also an archaic 100base-T4 standard that is 100 megs over four pair of category 3. Sorry, I'm a computer geek :shhh: but I'm slowly learning!

-Nelson

We usually use 3 cat3's for each drop. That way we are way ahead of the game with cat9.

johhz, would that be 'a cat of nine tails'.

I have a different take on this. When the question is about "phone service", the follow-up question is what type of "phone service". Let's take the CISCO 7940 IP Phone at my desk. The connection is 100BASE-TX from a powered Cisco Switch. From the phone, a cable runs into the back of my PC. If it was Category 3 cable between the switch and the phone, I would be in a world of trouble.

So yes, the IP Phone is not bandwidth intensive but the phone acts like a repeater sending the 100BASE-TX connection to my PC.

If you can guarantee that the "phone service" will never be IP, then go ahead an run the Category 3. If there is any doubt what so ever from the end user, do not run Category 3. Run Category 5e as a minimum. I would normally say Category 5 because that is all 100BASE-TX requires but officially it was obsoleted in April 2001 with ANSI/TIA/EIA-568-B. Now with ANSI/TIA-568-C it is still out of the standard but you can still find the cable around. If IP over 1000BASE-TX does take off, Category 5e would be a wise investment.

you miss the point ,no one here is suggesting running Cat 3 for Data and certainly the question would be asked as to "what type of phone service "and if VOIP is the answer then cat5 would certainly be used

if we are doing dual drops as we usually do then a Cat3 for voice and Cat5 for data is all that necessary

if the customer decides to go VOIP at a future date then the cable to the back of his PC will be on the Cat5 data connection back to the switch

that's whats happened in every VOIP conversion Ive seen

I just talked about this with the telecom guys at my school. Their current standard is to run a cat 3 for voice, normally split out into two jacks, and at least one cat 6 cable for data. When they do end up switching to a voice over IP system, they will simply use the data cable, and run a cord from the phone to the PC. This seems to be what is done most of the time as it is.

...Their current standard is to run a cat 3 for voice, normally split out into two jacks...

I don't intend to get off topic too much, but what is the best way to connect two voice jacks in the same faceplace to one cable? I usually connect two pair to one jack and the other two pair to the other jack. Is this the best way?

-Nelson

that's what I do

blue /orange jack one

green /brown jack two

Same here.

Same here, I also use a blue jack on the first one and a green jack on the second one,So a year or two later I can just look at it and know what I did at that site.

What did they use here?

They will, so long as at least one end of the link allows you to manually set the speed to 10mb.

Otherwise, they auto-negotiate to 100mb, which doesn't work so well over cat3.

An IP phone which does not allow you to manually set the speed connected to an unmanaged switch (which also does not allow you to manually set the speed) will auto-negotiate to 100mb on cat3 and there isn't a thing you can do to fix it, other than replacing the switch.

At one time (ca 1994) there was equipment available which could use all 4 pairs of cat3 for 100mbps. (100VG-Anylan and 100BaseT4 were the specs).

It was never very popular, and I have never seen any of this equipment.

Incidentally, how do you all terminate cat5e on 66 blocks? I have done it two ways:

1)The usual way, as you would do with cat3 and lower: Untwist the cat5e all the way to the comb on the side of the block. This requires untwisting the cable for at least 2-3 inches. What a pain.

2)The cat5e way: Maintain the twists up to the terminals. This only requires untwisting the wire about an inch or so, but requires that you make sure you've got the 66 punch tool oriented correctly, as cut needs to be facing UP for white/blue and DOWN for blue/white and so on.

I find that method 2 is much quicker. It also has the advantage that the installation should comply with cat5e requirements if you used a cat5e 66 block.

The way I am talking about is shown on the left side.

Actually both ways make you untwist about the same amount. With the second "CAT5e way" that inch doesn't give you much to grab onto with your fingers to put it in the clip. Only difference is that you want to maintain the jacket strip right up to the fanning strip and twists right up to the clips. That right there is a PITA and together with alternating the cuts is the reason 66 blocks aren't used much for data.

-Hal

The average cat5e cable is going to require you to undo about 6 more twists between the inner 66 clips and the comb. That's not insignificant, and is part of the reason that I find the cat5e way faster.

Well, not really. The proper way to terminate CAT4 and up on a 66 block is to bring the whole pair through the same hole in the fanning strip. Then, the tip conductor turns up into the upper clip for the pair and the ring conductor turns down to the lower clip. The untwisted cable pair length is less than 1/4", well within specs.

Cat 4? do you mean Cat 5? :shrug:

No, I meant CAT4. It all started as CAT1, 2, 3 and 4. The "professionals" have deemed most of them obsolete.

Gotcha...I have never actually seen Cat 4...

Still got a partial box....had a 20 year tech see the box and thought it was miss marked....

I find that quicker and easier than doing it the wrong way.

There never actually was any specification for CAT1 that I could find, it's performance was "unspecified", apparently a catch-all category for cable that had not otherwise been classified, such as quad, AT&T DIW, thermostat wire, zip cord, etc.

There were (and still are) some cable manufacturers making cable they call CAT1. I am unsure what the point of this cable is..why they would make it or why anyone would buy it. What I have seen of it (there is some in my mom's house--it's made by Essex and says CAT1 right on the jacket), it is at least twisted pair...and will work for 10BaseT, at least for short runs.

Hey its a picture of AT&T's DSL Support call-center!

dwflood, That was low, uncalled for, and the funniest thing I seen in several days! :rofl: John C.

Isn't that George Hamilton????

I went to Greybar Elec for cable supplies, and ended up buy Cat5e for phones, because it was cheaper than Cat3. Go figure.

Well, that won't be true for plenum. The reverse pricing for riser is because they don't move CAT3 like CAT5e because everybody has been brainwashed. You also have to consider who you are buying from, it's Graybar after all.

Then again that could work. Just tell your customers that CAT3 is more expensive so it must be better.

-Hal