Hello Everyone,
I am currently going through CBT Nuggets CCNA class. I have been enjoying it. Early in the class, they discussed various physical layer standards and I was struck by the following. Per the class, 10gb transfer speeds are supported on CAT5e cable up to 45m.
When doing research online, every site I bump into states CAT5e is not supported to transfer 10gb. Who is right here?
For reliable 10Gb, you need a shielded cable. Cat5e is NOT shielded.
I mean give it a shot not all cables even of a certain “Cat” are created equally. Terminations, patch pannels etc all play into it working well.
I am more interested in what the standard is. Much of the internet says to not use Cat5e for 10gb, CBT Nuggets says otherwise. I have been unsuccessful in finding a confirmed source of truth.
Admittedly, this is merely my own curiosity as if I were cabling a new office, I would not risk using Cat5e for 10gb transfers.
Youll need to find the International standard ISO/IEC for it
Good write up on officially supported stuff
Thanks folks. I guess I have to ding CBT Nuggets here as they should have put in their content a disclaimer to the effect of, “Cat5e may often transfer 10gb in a homelab or under very ideal circumstances but it is not officially recommended. In a professional\production environment, Cat6e should be used for 10gb transfers.”
At the same time, I am sort of elated as I was under the impression Cat5e could not transfer 10gb under any circumstance. I have some short cable runs in my house, with little interference that I hope will serve me well when I upgrade to 10gb.
Does 10GBase-T require more than 100MHz frequency? If so, that means it cannot conform to TIA Cat5e spec (and IEC 11801 Class D) which requires only up to 100MHz.
Im not absolutely positive on this, but I thought the clock frequency of 10GBase-T was 156.25 MHz. Edit: It is actually 156MHz at the MAC level, but the actual PHY runs at a 322MHz clock rate as per 10.3125 GHz aggregate wire bit rate / 32-bits over the bus.
While I often think that just because the masses say something does not make what they say necessarily true, in this case I believe it is. After all, this was one of the reasons for 2.5gbit and 5gbit speed grades, to take the basic specs behind 10GBase-T and bring them down in clock rates to allow Cat5e to operate at higher speeds over existing cabling without having to make such a large jump.
At the same time, I am sort of elated as I was under the impression Cat5e could not transfer 10gb under any circumstance.
Yes, cat5e can often work in 10gbit situations in homes. I dont believe it conforms to any specs, but it does often work as much of the cabling is of very high quality these days and works beyond specs.
The more I look, the more it seems Cat5e is not officially supported by the standards set by ISO/IEC (Thanks Mutation666 for that).
The primary reason I cared about this topic is to be informed when people ask me questions. My answer to family and friends (and colleagues) moving forward will be -
“Per the standards in the industry, Cat5e is not rated to support 10gb transfers. If new cable is being ran, make sure to use Cat6e or higher for 10gb runs. Unofficially, Cat5e will transfer at 10gb under ideal circumstances.”
They really shouldnt be teaching that it is supported in a CCNA class though.
I agree, it is why I took the time to research and post on this beautiful forum. I did not want to promulgate inaccurate information. I also contacted CBT Nuggets.
I used CAT5e on 10Gb network couple of times. Usually, they are only short runs less than 6 feet at the same location in my cases. For anything longer than that, I will use shield cables as someone suggested.
Cat 5e is fine for 10 patch cables but if you’re running in wall or it’s existing expect, 2.5-5g
Anything less than cat 6 really is a crap shoot in wall.
Also while you may think it’s low interference things like thunderstorms can knock out unshielded cables when your pushing their limits.
It really depends on the length and your physical plant.
Short lengths will generally be ok, as not as susceptible to interference. I’ve had a house wired with 5e (before 6 was available) and the runs where generally 50-60ft or less. 10gbe ran ok in that low density environment.
If you have a situation where many cables are bundled together then cross talk and interference will certainly affect the connection. You might get a physical 10gbe connection but the line may have errors. Even a 1% retransmit rate can be detrimental.
I’ve done proof of concept before using 5e then as part of the budget upgraded to 6. It’s annoying but best way to ensure it works all the time in a sense or interference prone environment.
I can tell stories of how even wifi signals caused inductance in audio equipment that also affected network performance. Good cabling is a requirement outside of the home.
Hope that helps!
Wel, i am going to see how well shielded Cat5e is going to do. I need a run from a 10Gb switch over copper. The switch can auto negotiate 10/5/2.5Gb and the connected devices will do 2.5/10Gb.
Even it is gets 2.5Gb max i am happy.
Thx for your post, it saved me from buying CAT6a cable since i still have a box of CAT5e
Love necroing threads. Especially when it’s my first post.
I find this to be a fascinating topic. I don’t like the word “supports”. I think it’s misleading. A bridge rated at 5 tones could probably support a 10 ton load once in a while. I like to use the term “officially rated”.
I like the idea CCNA is teaching that 5e can “support” 10Gb. It causes you to critically think and dig deeper into ratings and how cables get them and what is required from a cable to carry a certain speed over a given distance.
Where is this so called “shielding” I hear so much about?
I’ve opened up rated 6 and 6a to find nothing more then a polymer membrane separating two pairs, or a few strands of plastic “string”. Where is this metal foil or mesh I hear so much about? Is the shielding from electronic interference coming from pixy dust?
I’ve opened up Cat5e to find individual each twisted pairs separated by a polymer core and wrapped in a foil jacket. Was that a company going hard 20 years ago before 6 was a standard? But clearly a foil wrap or mesh isn’t part of the standard because I have yet to open a 6 or 6a cable to find any such thing.
Also, Cat6 and Cat5e are indistinguishable. Don’t let the industry tell you different. How many people are going to loose their minds over that comment? Cat6a on the other hand…
Fun fact, most Cat5e is UL rated to 350MHz. The standard for 6 is 250. The standard for 6a is 500. 10Gh needs 500 for it’s full potential. So 6 isn’t even official “supported” for 10Gb.
Or, and here is where people are really going to loose their minds, if you say 6 can support 10Gb, then you have to say 5e does too.
Cat 6 only supports 10Gb speeds up to 55 meters.
6a is the full standard for 10Gb.
You see where I am going with this?
Bottom line being, I like to look for a UL rating for the cable. Not what Cat version it was branded with.
Disclaimer: I haven’t touched every make and model of every manufactures Cat5e through Cat6a. But the only cable I have yet to come across that actually had a metal foil or mesh jacket/shielding was 5e.
So, does 5e “support” 10Gb? No, but Cat cable rated above 250MHz does support 10Gb up to 55m runs.
It is true that most Cat6 is not shielded. Most Ethernet cable of any spec is not. You usually have top go out of your way to specifically buy “STP” cable which is a basic foil shield, or S/FTP and S/STP for double shielded cable types. To be honest, shielding doesn’t matter in most use cases. It matters when you are in a company setting where all cables come back to a server closet and the installer bundles them as they get close to the room in groups of 30-50 cables all zip tied together and they run parallel in that bundle for 50+ ft. Then the shielding can help reject the coupling interference of all the wiring. It also matters when running in industrial areas with high voltage (480-600v or more) power wiring, as the magnetic field of that power wire can be quite large. And finally it matters when going outdoors with the cable, to provide proper lightning surge grounding. But the majority of homes have no use for shielding whatsoever, and most small and potentially even medium sized businesses have no use for it either.
