Feeder cables with 10 Gig?

We're about to rewire our office with a high-grade, shielded Cat6 cable that is supposed to support 10gig up to 55 meters (yes, I know there's no guarantee since there's no ratified standard yet). Our hope is that this high-grade wire will eliminate the need to do another network rewire for at least another 10-15 years. But there's a good chance that our server room may move from it's current location in the next couple of years. We could always use feeder cables to extend all the cable runs from the old server room to the new, but my question is, should we?

If we hope to someday run 10 gig over this copper, will a properly-done feeder cable be as good as a single unbroken run of the same cable over the same length? Do I run the risk of performance loss, increased exposure to EMI, or any other problems by using feeder cable in this scenario, or would I need to do another complete rewire to get the cable integrity I'd need for

10gig? I realize I'm trying to predict the future of a technology that barely even exists today, but I'm hoping someone with particular expertise or experience in this area can tell me, on a gut level, what they think. I'd like to make the choices now that stand the best chance of serving us well for the future. In case it matters, we'll be running PoE over this wire today, and I can't image that 10gig networks won't try to do the same thing.

All comments appreciated, and thanks in advance.

Bryan

Reply to
BJ
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I have no expertise in wiring, let alone wiring for very high speed, so the following might be wrong or irrelevant:

What I have read is that often the greatest challenge for high bandwidth is in the connectors, as it is at the connectors that signal reflections are generated, and at which impedence matches become an issue, and at which phase distortions are most sharply introduced into signals.

This would suggest that if your aim is cutting-edge bandwidth, that you would be better off with an unbroken run.

I've read the odd tidbit about very high speed wire networks; one of the suggestions I've seen is that in the future, cable interconnects might no longer be passive electromechanical systems, and might instead require some amount of electronics (I don't recall if they would be passive or active), such as in order to reduce echoes. It wasn't a "repeater" as such, in that the signal would not be regenerated, but it was more than a simple capacitor.

Reply to
Walter Roberson

Why shielded?

It can't be as good, as there'll be another couple of sets of connectors and a patch cable between them (or at least a Cat6 splice).

An unknown spec for 10G, unknown PoE interactions, adding splices, "10G PoE midspans" (whatever they might look like), I think you are planning too far into the unforseeable future.

I can't even buy 1G PoE midspans today...

Reply to
William P.N. Smith

My research on 10 gig over copper indicates that Alien Crosstalk is one of the bigger concerns. Our office is small enough (just over 100 drops) that it's worth it to us to pay an extra $8,000 or so on the entire job for sheilded, if it'll increase the chances we can someday do 10 gig over the wire. Shielded cable will minimize Alien Crosstalk and provide additional protection against EMI (in case some yahoo installer of something or other ever messes around in our ceiling and unwittingly does some things normally unfriendly to ethernet cable). It'll be of some value to us today -- peace of mind of having reduced emi, no alien crosstalk, etc -- and has the potential to be of much greater value to us 10 or more years from now. We'll be pushing PoE on our gigabit network within a month or so, and as I said, I can't imagine they won't eventually try to create a PoE spec for 10 gig, tho granted, it may be a long way off yet.

That's my gut feeling; I'm hoping to get expert corroboration from cable installers on this.

Yeah, I know. We're just trying to do the best we can to future-proof the upcoming rewire, so I'm asking a few extra questions today. An ounze of prevention, and all that. Might not matter in the long run, but I'm gonna try anyway.

I just bought several 24-port GigE Catalyst switches that do PoE; got a great price on 'em too.

BJ

Reply to
BJ

Great info, thanks; I may forward it to my cabling guys for their reactions, and post them back here.

BJ

Reply to
BJ

Well most people (except ethernet engineers) use coaxial cable when they need high bandwidth. It isn't so hard to make an impedance matched coax connector if the connector parts have the appropriate diameter. It is somewhat harder for UTP.

I agree, though it might be that with good connectors the reduction in length is not so big.

Active terminators are popular for SCSI termination. I suppose that could soon be true for network cabling.

-- glen

Reply to
glen herrmannsfeldt

Right now unless you have a lot of money, I dont see the need or reason to put in augmented cat 6, especially if you say you may move your server room.

Augmented Cat 6 is a lot more money than Cat 5e. If you need to run multgigabit applications now, go with fiber!

15 years is a lot of time, and lot can happen down the road...

Perkowski

Reply to
Perkowski

1 suggestion is put wiring closets around the building to reduce the level of cabing needed to the computer room - that way when you move it you can concentrate on the backbone links....

and if you go with 10G on fibre you may want single mode - so put both s/mode and m/mode in, but only terminate what you need (since connectors, testing etc is where a big lump of the money goes)

Reply to
stephen

Actually, I had it quoted both ways. The Cat 6E+ quote was only 15% more than the Cat 5E; to me that's worth the higher quality cable with significantly more headroom. Even 1G stuff should run with fewer issues and perform better. And as I said, we don't need multigig speeds now, we're just trying to stack the deck in our favor for the future. Fiber itself it's too bad now, but supporting it at the endpoints is what gets pricey, as I understand.

True!

BJ

Reply to
BJ

I think the original poster's request for cabling that'll meet standards in

10-15 years is unreasonable.

I try to imagine asking the same question in 1991-1996 and wanting 1 gig speed. We all know what happened there.

Reply to
none
15% more?

A 1000 foot box of Cat 6 Augmented is almost double the price of Cat 5e the last time I checked. Make sure you are getting plenum cabling. How much you paying for each drop?

Perkowski

Reply to
Perkowski

Installation labor charges are probably about the same, though.

-- glen

Reply to
glen herrmannsfeldt

Plenum isn't required in our building, so we saved on cost there.

BJ

Reply to
BJ

Not required?

Where you operate in a shoebox?

LOL

sorry

Reply to
Perkowski

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