10GBase-T cable length question

[Mathgeek]

Hi all, I am in the process of assembling my first FreeNAS server and sorting through some networking questions while waiting for the last component to arrive. The guides are all very good - thanks to all who put them together.

Regarding networking, I would like to take advantage of the cabling installed in my home to connect my workstation (on third floor) with the server which I would like to place in the basement. I have a 72 ft (22 meter) run of Cat5e (350mHz) connecting the two. Has anyone been successful running 10gbase-t on a run of this length? I have seen comments that support both 'yes' and 'no' in various resources, so assume the answer is 'maybe' and would appreciate any first hand accounts. Even if it required upgrading all the termination points, utilizing the existing 4 yr old wiring would be a handy solution versus having someone re-run 6a or fiber.

Thanks again. I look forward to being a constructive noob and not asking too many other stupid questions.

-A

 

[Ericloewe]

10GBase-T requires Cat.6 at the very least. That's good for 30m, theoretically. For full 100m runs, you need Cat.6a or better.

 

[cyberjock]

You ask stupid questions! Just kidding.

Actually, this is why I'm just going with fiber in my new house. Tired of having the constant game with copper wires. I'll be running CAT6 throughout my house, but a few locations will also have fiber. Fiber is nice because of the rather long limits on length that are acceptable. Good enough for just about any home you and I could ever afford. :P

 

[DrKK]

Just to clearly answer the OP:

22 meters of Cat5e is a no-go for 10Gbps. You're not even close. I would not expect that to work at all; I would not expect the negotiation procedure to even acknowledge 10Gbps.

 

[Mathgeek]

Thanks cyberjock and DrKK. I finally have my server up, have finished burn-in and am experimenting with the system to learn before using it more robustly at home. Frankly, it is remarkably solid and I am enjoying learning (for example, it took me a while to get to the point where I *almost fully* understand how I could get 8Gbps writes but only 2.4Gbps reads).

This is a great community of people who help the noobs out (and bite just enough when they screw up).

A

 

[DrKK]

Thanks cyberjock and DrKK. I finally have my server up, have finished burn-in and am experimenting with the system to learn before using it more robustly at home. Frankly, it is remarkably solid and I am enjoying learning (for example, it took me a while to get to the point where I *almost fully* understand how I could get 8Gbps writes but only 2.4Gbps reads).

This is a great community of people who help the noobs out (and bite just enough when they screw up).

A

We value the concept of a user having his own skin in the game. That's why we bite a little bit. :) It is the FreeBSD way for users to understand what they're doing, and why.

 

[Darren Myers]

You ask stupid questions! Just kidding.

Actually, this is why I'm just going with fiber in my new house. Tired of having the constant game with copper wires. I'll be running CAT6 throughout my house, but a few locations will also have fiber. Fiber is nice because of the rather long limits on length that are acceptable. Good enough for just about any home you and I could ever afford. :p

Let me know when i can move in, i have fiber too...sooo i think it'll be a good match :P

 

[Mathgeek]

So, I gave it a try anyway. Full link and no errors on send or transmit over many GB. Ran out of time to benchmark transfer speeds versus my current direct connected setup - may do that next weekend. Came as a nice surprise.

 

[DrKK]

Wow. You ran 10 Gbps over 22 meters of Cat5e? Pretty sure that violates the laws of physics--?

Hmph. You learn something new every day.

Well I can tell you this: Cat5e is not certified for 10Gbps, it's actually not even supposed to work at all, with the attenuation etc. Just in case I was being stupid, I looked up the specification to confirm.

 

[Ericloewe]

Well, UTP Cat. 6 is just UTP Cat. 5e with tighter tolerances, so it's bound to work on good Cat. 5e cable for short runs. I'd bet on more than 5m though, so 22m comes as a surprise.

Low noise environments also help.

 

[Mathgeek]

I was pleasantly surprised. The cable is Honeywell 350MHz and I believe the termination panel in the basement is Cat 6. I will take a closer look. Unfortunately this now means I'm in the market for two 10Gbps switches...

 

[Ericloewe]

350MHz? Cat 6 is supposed to allow for 250MHz of bandwidth, no wonder it worked. It's a stupidly under-categorized cable.