Slashdot Mirror
Cable Wars: Cat 6 vs Cat 7 vs. Cat 5e?
stone22 asks: "My company has decided to install a gigabit link. This will be initially used only for testing purposes, and on the longterm as a backbone for our corperate network. We allready decided to use copper, but what standard ? I've heard about problems using cat 7 cables (cross talk, bulky cables, non-standard connectors) so I could really use some hints from all you cabling experts out there."
A bit underqualified, aren't you ?
Resign at once and let people with a clue take your job moron.
Most interfaces, cards, and things of this nature have a fucking manual. I have read them myself, while shitting at the toilet at work. It clearly tells you, copper or fiber, the types of cables and lengths to use.
I would also say that fiber is a better backbone that Cu, and CAT 5e has always worked FINE with GigE - because that's what the fucking manual says.
Here, look, a 3C996-BT manual:
http://www.3com.com/products/en_US/result.jsp?sel
Direct Link to the PDF:
http://support.3com.com/infodeli/tools/nic/3c996/
In Section 11, Specifications:
CHAPTER 3: INSTALLING THE HARDWARE
Connecting the Network Cables
The adapter has one RJ-45 connector, for attaching the system to an Ethernet
copper-wire segment. When automatic link negotiation is disabled, the port can
be configured for 10 Mbps, 100 Mbps, or 1000 Mbps signaling and either
half-duplex or full-duplex operation.
Follow this procedure for connecting a network cable to the Gigabit Ethernet
adapter:
1 Prepare an appropriate cable. The following table lists the cable characteristics for
connecting to 10/100/1000Base-T ports:
Table 3 10/100/1000Base-T Cable Specifications
Port Type Connector Media Maximum Distance
10Base-T RJ-45 CAT 3, 4, or 5 UTP 100 meters (325 feet)
100/1000Base-T RJ-45 CAT 5 UTP 100 meters (325 feet)
15
2 Connect one end of the cable to the Gigabit Ethernet adapter.
3 Connect the other end of the cable to an RJ-45 Ethernet network port.
1000Base-T signaling requires four twisted pairs of Category 5 balanced cabling,
as specified in ISO/IEC 11801:1995 and EIA/TIA-568-A (1995) and tested using
procedures defined in TIA/EIA TSB95.
when the cable is properly connected at both ends, the adapter port LEDs should
be functional. See the table in Introduction for a description of adapter port LED
operation. For driver installation and configuration instructions, refer to the
software configuration for that specific driver.
Okay, so now it is clear that you are a waste of time, and a fucking illiterate idiot. Please stop wasting everyone's time, enroll in a TOEFL English class or some shit, and realize your High School in Alabama failed to teach you reading skills. You fucking idiot.
It must suck to be you, stone22. Quit sucking cock and balls and get your GED.
While I can't insult you as well as the AC above, I do have to say that if you are seriously considering using this as a backbone pay the extra initial cash and lay fiber. You can go with MUCH longer runs, eliminate crosstalk, and generally find that life is much simplier. But if you have to have copper, Cat 5e UTP cable w/ RJ45s should be more than able to handle your GigE network.
Peace.
72 CD D7 52 D0 7E D8 47 44 91 D5 84 D1 59 F1 A9-This is my 128bit integer. There are many like it, but this one is mine.
Dude,
What? Give the guy a break.
Mental Illness alert!! Anger problem.
stone22, how the fucking hell did you ever get a job?
BTW, this article could have been a better troll if you had also mentioned that your company uses Linux and is thinking of open-sourcing its products under the GPL.
Please log on before posting stuff like this so that I can use the "Foe" feature. Thanks.
How the hell are people supposed to find out anything unless they ask? If you think answering a question is "beneath" you, just ignore it, o omniscient one.
Yes, I know a google search (or other search engine) will find 99% of the answers people ask.
Google has a search engine. Its a damn fine search engine. It searches many a site, and caches them in case they are no longer there when you search. Its good for hunting down background information about systems.
However, where google really shines for problem solving is that it archives usenet. Guess what, odds are, your question has already been asked and answered. That's why a lot of people are upset about the recent spat of 'Ask Slashdot' questions.
Fiber rules...nuff said.
Damn, I think we've all just witnessed the birth of another MS fanatic. This idiot is the same kind of moron I see installing MS software whenever they get the chance. In-fact, this is the same kind of moron I see doing just about anything to a system that should have never been done..
Either take a few BASIC networking classes, and go to the efforts to get some BASIC certifications, so you can at least claim you're certifiable. Hopefully, you'll realize you're not cut out for this type of work. Either that, or just save youself the time and trouble, and do us real sysadmins a favor by getting a job you can do, maybe digging ditches, or flipping burgers...
Its good for hunting down background information about systems.
That is, if you're an expert at formulating queries. If you really want to reduce the number of "Ask Slashdot" questions that Google could answer better, then don't just gripe that it should have been an "Ask Google" question. Instead, teach your fellow users how to formulate an effective query.
Will I retire or break 10K?
You can really tell that a bunch of sysadmins and not highly-paid wire jockies read slashdot... A cable is a cable, indeed. LOL.
. as p
e 2. shtml
Seriously, in our lab tests, Cat 7 DID have some problems with a number of our servers- and this included non-home-grown stuff like NetApps and Suns. Cat 6 worked just fine. Check a couple of the links here for some more info.
Cat 6 actually did provide us with better benchmarks, btw.
http://www.siemon.com/white_papers/01-01-23-sff
http://www.networkmagazineindia.com/200205/kron
The most disturbing thing here is the general downward trend of respect in the Slashdot community. And why did the first post get rated a "4" when it posted info from a NIC manual saying NOTHING of value about cables or comparisons?
On the other hand, a search of Google probably would have found most of this out... but I suppose it's always nice to have a first-hand confirmation from someone who's actually looked at the question.
This is really trivial, guys. If the twits had the sense to pound sand (and use Google), they wouldn't be asking a bunch of slashies, now would they?
You're running a gigabit link with copper? Are you retarded? Seriously, please answer.
Yeah, you point out the manuals and information and stuff like that. I'm sure that if he has the ability to post on /. that he has the ability to read.
What if he's looking for user experiences in the real world (you have been in the real world right? You don't just stay in your parents' basement compliling kernels over and over again?).
Manuals will tell you the how to, but not the how good.
I guess he got his answer - ask the slashdot crowd and all the condescending assholes come out of the woodwork to parade their 133t status.
And to stay on topic, I have found that cat5 is perfectly acceptable for gigabit ethernet, but I've only used it point to point, not as a backbone, and then only using a G4 tower and a Powerbook - obviously due to the aestheticly pleasing nature of these computers they can't be 133t, and hence my opinion doesn't count.
Have a nice day.
go fibre, period, why would you run a backbone on Cu if their is any though of crosstalk?
Cat6, Cat7? f*k them,
Cat5e is the way to go, its in the spec for GigaEthernet, why not?
but really, go fibre on the backbone
Well, whoop-dee-doo! Congratulations, you Read an FM. I'll bet the submitter did, too. Do you really think the posters let such questions through in order to substitute some loser's RTFM? We all know how to hunt down specs, standards, and manuals. If that was all there was to it, they could replace /. with a redirect to google. Such questions are not in to provide you with the opportunity to be a snotty little pissant, but for the discussion they stimulate. Here, there's access to the experience, wisdom, and judgement of hundreds (thousands?) of geeks, even if, so often, some snotty little AC demonstrates such limited thinking. Does anybody really think that all the answers are in the standards and manuals? On this topic, for instance, maybe somebody will be able to make the case that there is no reason for catVI or catVII, V works just fine, per the spec. Somebody else may be able to show real benefit, maybe just in certain circumstances, to useing more expensive cable. It is to be his backbone - maybe he should be looking at fibre instead. Whatever.
While I agree that if the submitter didn't even look at such docs as you provided in your crapflood, he IS an idiot, that has no bearing on our responses to the question, and responses to the responses. So, go get a cup of coffee, read something good, and calm down. Review the thread in a couple of days. There'll probably be something in it you didn't already know. Really. It's possible.
Of course, none of that tells us why any of that is a good choice. I'm tired of the worlds rush ahead without clear information mentality...The United States is not alone in that department.
and I havent been getting any usenet hits... Am I doing something wrong?
This is one of the most worthless article I've ever seen.
No, not because of the premise, I was actually curious what the answer was myself because I want to lay an inexpensive 1Gb network in my house at some point ("because I can").
It is worthless because of all the people who ridiculed the poster with the various RTFM and "look it up on Google" responses. Most other responses were to use something (fiber) that the poster seems to have obviously ruled out (maybe cost, maybe convenience, doesn't matter), so those don't help much either but at least they were trying.
He wanted to ask the opinion of his peers, not rely on what a manufacturer said or possibly out of date material. Most of the responses trashed him.
Why do people bother to take the time to produce non-responsive or patronizing answers? If you don't like the question, or you think he should spend his time elsewhere to get the answer, then simply don't post.
A lack of response is a much better way to get someone to go away than to waste your time writing and the time of everyone who pops in to see what the consensus was.
It is more productive to voice thoughtful opinions (reply) than to judge (moderate) others.
Try here
First, you don't give enough information in the article for a really good answer. You say that you want to lay a backbone cable but, you don't give details like the distance it has to traverse or the environment it will be in. You also fail to say how many nodes might be directly attached to this backbone. These are important details in the decision process. That said, read on....
I would have to agree with some of the other posts, you should use fibre. The other posts don't say why you should though so, here's why.
First, fibre is not going to be a lot more expensive than good copper. Sure, it is a little more but, the extra cost is worth the benefits. Benefits include increased distance, no interference at all and, most importantly, room to grow.
In laying a fibre cable, even a small one, you don't have a single data path, as you do with Cat 5-7. Even small fible cables usually bundle three or more pairs in the cable. That means that you can VERY easily double or triple your bandwidth in the future by lighting a second pair. Or perhaps you need a completely separate data path for some other service like maybe you want to interconnect a couple of legacy PBXs, or a video conferencing system, or a security system, who knows what.
The next thing is that fibre gives you even more room for growth. Sure GigE is great but, will it meet your needs in the long term. Already 10GigE is a reality and 40GigE is well on it's way. These can easily be implemented in the future, if you have fibre. I doubt however that Cat 5-7 will ever run 10Gig and definitely not 40Gig.
There is also a technology called Dense Wave Division Multiplexing (DWDM) that uses multiple lambdas or wavelengths on the same fibre pair. Using this technology it is possible to have 64 data paths on a single pair of fibre, that's 128Gbps aggregate bandwidth!!!!! That's all over fibre. With Cat 5-7 though, you will never have more than 1Gbps and only one datapath.
Fibre is definitely the way to go for a backbone solution. I hope this helps.
I design and test the physical side of ethernet for a living, so I think I state with all honesty and some authority that using anything more than cat-5 cable is wasting money. Kinda like buying 94 octane when your car is designed for and runs fine on 87. It has more capacity than you will ever use. Ok, true cat-5 cable may be hard to find, so when I'm saying cat-5, I'm also mean cat5e. I agree with the other posters that fiber is the way to go for a backbone, but copper is quite a bit cheaper, and pretty reasonably priced. According to the Ethernet spec, fiber is actually held to a higher standard in terms of bit-error rate (fiber is 10^-12, where copper gigabit is 10^-10- I'm pretty sure, I have them in spreadsheets to check against, but anyway, fiber is better) On the other hand, on the interfaces I've tested, the BER on maximum loss (copper) cable is usually far better than 10^-10 so that isn't much to worry about.
Be careful if you are thinking about installing fiber for possible use for 10GbE- there are a bunch of standards, and most of them seem to be incompatible with most current types of fiber, such as requirinig very small diameter single-mode fiber. At the moment the 10GbE world appears to be dominated by the long haul guys, not the LAN manufacturers, so cheap connectorization/fiber is not necessarily high on their priority list.
Remember to keep the length under 100m (as it says in the spec) and don't go through a lot of patch panels (since each connector adds loss). If you are going for maximum length, be very careful how you cut and crimp the cable- the more you can maintain the twist in the wire the better, and the more matched each wire in the pair is, the better.
Interesting fact: Since the loss of cat-5 cable is not well defined per unit length, The test cables (for 100Base-TX) are not specified in terms of length, they are specified in terms of loss. The maximum length cable that you test to is not a 100m cable, it is a 10dB loss at 16MHz cable. With good quality (cat5e) cable, that works out to around 135m.
You've really not given enough info in your question for anyone to make even close to an educated guess. All things being equal, if it were me, I would have several pair of Single Mode fibre installed. You will probably have to spend a bit more upfront on the installation (vs multimode) and on your connectors (ie you'll need LX GBICs, etc) but you will be 'future proofing' your backbone for upcoming technologies (ie 10Gig, 100Gig, etc). If you can only do copper and you are within the distance limitations of the 1Gig spec, then Cat5E will do....but you'll never get much more than 1Gig out of copper wiring.
Perhaps you should check again? 3COM makes a rather nice PCI Fiber NIC, it apparently even does onboard IPSec.
All editorial writers ever do is come down from the hill after the battle is over and shoot the wounded.
You'd really be better off going with fiber for gigabit. Yes, Cat5e (and regular 5 if terminated correctly) will run gigabit, but there are some idiosyncracies that you might run into. Your NIC manuals should specify the requirements, I can't remember them off the top of my head. Also, we've found that different vendors support gigabit in slightly different ways on copper. We can't get SMC 1000-BaseT and Cisco 1000-BaseT to talk to each other. We ended up swapping out all our 1000-BaseT links to fiber and haven't had any troubles since.
So, go fiber if at all possible. If you absolutely have to use copper, use 5E cable from a reputable vendor (Belden, Berk-Tek, Mohawk, etc.) and use GOOD jacks and patch cords. I prefer Panduit and spec it for all our jobs, but others also make good stuff. Don't scimp on the patch cords either, these cheapies that you find many times don't test real good. Go for 5E rated patch cords with the short plugs and gold contacts.
Jason
"FORMAT C:" - Kills bugs dead!
I agree that Cat 6 is already superfluous for standard applications such as GigE Ethernet that operate in the 0-100MHz band (though theoretically it may give you somewhat more headroom against sloppy terminations in terms of overall testing qualifications).
I guess higher-quality TP can be useful as a general-purpose wireline carrier for a wide range of analog/digital signalling (through the use of baluns and media converters). If I remember correctly, Belden had some nice info on this. With a good active balun you can carry up to 4 channels of baseband (and limited broadband A/V), USB, Firewire, whatever. Including home run distribution.
When my house was built 2-3 yrs ago, Siemon's TERA System 7 (impressive 1GHz non-RJ termination system) was already being prototyped. Unfortunately, Alcatel's "draft Cat 7"-level cable (600MHz fully pair-shielded TP) wasn't available yet and I couldn't find anything else. So I went with Mohawk's 2nd-gen GigaLAN "Cat 6 plus" UTP (though Berk-Tek and others were close competitors) along with some Commscope 2+2 bundled cables. And mostly Siemon System 6 and Leviton for the termination (again, Hubbell, Panduit, etc, were all very similar). Note that back then Cat 6 hadn't officially been ratified yet.
Tip #1: Terminating the 22AWG Mohawk UTP with its thick jacket and crossweb can be a pain on those closely-packed plates/panels.
Tip #2: Try your local supply distributor (Anixter, Anicom, Graybar, etc) to see if they'll sell you these bulk spools for much, much cheaper than retail Cat 5 equipment. Places like DataComm Warehouse is also good, but they don't usually stock the more esoteric structured cabling parts.
asked. Don't be so mean to him, you have to start inexperianced once. Maybe he wants a second opinion because there might be a better solution than what he read about.
You have to realise that trolls are all part of the fun of Slashdot, fsckwit.