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[tickmike]

I'm just thinking about what/how to connect between my 'Hardware firewall' (Smoothwall) to my 'Hobby' room (20M in floor ducting).
From smoothwall out-put are three LAN cards, 1. general internet use, 2.wireless devices, 3. DMZ (DeMilitarized Zone) for my remote backup server.

Do I need to use 3 separate cables for these services ?  or can I use 1 cable with three twin twisted cores ? (will there be 'crosstalk?).
I have plenty of '6 core phone type' cable.
 

[roseway]

You need two cable pairs for 100 Mbps ethernet, and four cable pairs for 1 Gbit ethernet, so you can't do it with a single cable, even if the phone cable were suitable (which I doubt).

[guest]

Proper CAT5e and CAT6 will usually have a centre conductor and individual pair screens, then an overall screen over that. You need to terminate the screens and centre conductor to a local earth (on the same mains ring ideally) otherwise long (30+ metre) cables will have lovely antennas (the screens).

When I first put gigE into the house (all the main rooms have it now) it worked fine, but it knocked 4Mbps off my ADSL. Took me a while to realise it wasn't the pairs or the ethernet signals, it was the screens causing the problem. They were all acting as lovely dipoles

It was a gotcha for me, should have known better really but I got used to unshielded (screened) twisted pair cable being the norm.

[c6em]

Don't know about cat6 varients but.....

The wire pairs in Cat5e are not individually screened, there are just next to the other wire pairs in the cable
Standard Cat5e also does not have an overall foil shield around it.
Cat5e FTP does have a overall foil shield round the lot plus a drain wire for you to connect to earth.

I think the pairs in cat6 are individually screened - which would account for the much thicker cable size of cat6.

Ideally the earth for any screen/drain wires should a dedicated telecommunications one and be seperate from any electrical mains earth.

[guest]

I'm not talking about drop cables here - ie short 1-5m flexible ones from socket to machine, I mean the infrastructure cabling thats solid conductor and has a maximum bend radius etc specified. I'm assuming thats what he plans to install?

If you're going to use the drop cables then don't expect a lot on runs over 20m on GigE.

[roseway]

Cat5e cable doesn't have screens or extra conductors apart from the twisted pairs. It isn't certified for gigabit ethernet, but will generally work satisfactorily over domestic lengths of cable run. Cat6 cable does have screens and other features and is certified for gigabit speeds over cable runs up to 100m.

[guest]

Cat5e cable doesn't have screens or extra conductors apart from the twisted pairs. It isn't certified for gigabit ethernet, but will generally work satisfactorily over domestic lengths of cable run. Cat6 cable does have screens and other features and is certified for gigabit speeds over cable runs up to 100m.

All the CAT5e I've bought (several km of the stuff) in the last 7 years is exactly as I've described it, from multiple suppliers and in fact I have about 80m of it still in the garage. The last time I saw reels of CAT5e that weren't as I described was from some Manchester supplier around 2002 - Aria probably.

YMMV obviously.

Edit - just to make it clear, this is infrastructure cabling with an overall diameter of 20mm, its not drop cables. I know what the spec says, I just can't remember the last time I saw cabling that was minimum spec. There is ZERO point in CAT5e cabling in normal environments if its not for GigE. Anyway we'll have to agree to differ.

[c6em]

Well see the attached link to a Belden Cat5e FTP rated cable
http://cpc.farnell.com/belden/1633-100/1633e-category-5e-ftp-belden-100m/dp/CB09412?in_merch=Products%20From%20This%20Range

Foil shield and drain wire visible

UTP is no screening to either cable or pairs
FTP is for foil shielding to the cable but no pair shield
STP is for foil shielding to the pair but no cable shield

[roseway]

Edit - just to make it clear, this is infrastructure cabling with an overall diameter of 20mm, its not drop cables.

We're talking about different things then. That type of cable isn't (I think) the sort which would normally be used in a domestic environment. I have a couple of reels of certified Cat5e UTP cable which has a diameter of about 5mm, and there's no foil or screening or extra conductors. This is the type of cable I would expect to be used in a domestic ethernet network.

Perhaps what I should have said is that the Cat5e spec doesn't require shielding or extra conductors; the FTP and STP varieties exceed the standard specification.

(Sorry, I seem to be getting argumentative in my old age. )

[burakkucat]

Gentlemen -- The b*cat requests permission to comment. 

If sides are to be taken, I shall join forces with rizla. There is a difference between what typical suppliers (Amazon Market Place, eBay Shops, etc) sell and what one can obtain from a dedicated cable supplier. From the former, one tends only to be able to purchase Cat5e and Cat6 specification cable designed to be used as flexible patch cables. (rizla was, unfortunately, using the descriptor "drop cables".) From a dedicated cable supplier, one can purchase the single-cored, semi-rigid, multi-screened, Cat5e and Cat6 specification cable which would be installed in a building (preferably at construction time) as a certified "structured wiring" infrastructure.

So . . . yes, both opposing sides of this temporary misunderstanding are correct!

 

[roseway]

So . . . yes, both opposing sides of this temporary misunderstanding are correct!

I'll settle for that.

[tickmike]

After all this discussion I'm even more confused  .
This is like the cable I have, Unshielded twisted pair (UTP)    it looks like the picture !.
On below page.
http://en.wikipedia.org/wiki/Phone_cable#Unshielded_twisted_pair_.28UTP.29

I have used the 'patch cord' type cable (with the ends already on) for the other part of my network but it's not built in to the house wiring (yet) I  will gradually replace it and put some cabling in to our cable ducts and I can make a better job of terminating it with wall sockets.

[roseway]

Cat5e UTP cable is generally fine for domestic networking, but for a gigabit network you may not get the full speed. Cat6 cable is certified for gigabit transmission up to 100 metres.

[tickmike]

OK thanks, no chance of my old computers doing gigabit transmission

[roseway]

I suppose that the other consideration might be future proofing. If you were to use the infrastructure cable described by rizla, your network would be better able to support future needs, although of course it would cost a lot more now.