How to make a shielded cat6 patch cable

To what specific standard are you referring?

Hello,

I need to know how to make a cat6 shielded patch cable (sstp/fftp). All sites I have found explain how to build an unshielded cable (cat5/5e or cat6) :-(

Do you have documents or URL which can help me ?

No, it means the cable is shielded. There are plenty of low quality shielded cables around.

Your choices are stranded for patch cables and solid for "permanent" runs. You may lose some distance with stranded, but the maximum copper distance is 100M, except for 10 Gb, which is much less.

Fibre is the way to go for any significant distance at 10 Gb. If you're in a location, where electrical noise is a concern, fibre is the better choice.

Has the 10 gig over UTP standard been released?

In my case, shielded cables are used for long distance copper GigaEthernet and to be compliant with future Copper Ethernet evolutions.

My understanding is that the use of STP instead of UTP actually

*de*creases the maximum length over which copper ethernet can be guaranteed.

If you're really interested in longer distances, and/or worried about interference, pickup etc., then fibre would probably be a better choice, and has become reasonably affordable in comparison, whereas the price differential used to be considerable.

("fiber", for transpondian readers)

Simply don't mess with it! There is no good way to make it right without special equipment, so do yourself a favor and buy one (usually for less than $10 online)

Cheers! DA

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I don't know. However, I recall reading that it would only work over a few metres.

Argggghhh ! I thougth wrong things about shielded cables. For me "shield" was equivalent of "better quality".

Our purpose is to interconnect network equipments within several 19' rack-cabinet with copper gigaethernet links. Rack-Cabinets are close from each other but sometimes the link's length could be higher than 100 meters.

What type of copper ethernet cable I can use for short connections ? What type of copper ethernet cable I can use for long connections ?

Is yours above recommendations could support ethernet protocol evolution (like 10 Gb) ?

Finally, do you have links which could help me to choose my cables ?

I think you're confusing 802.3ak, which is a released standard for a short range interconnect over 15 meters of STP Infiniband cable, with the coming

802.3an standard for 10 gig Ethernet over 55-100 meters of some kind of UTP.

The cable vendors are going to tell you that you will need CAT6 or CAT7 cable for 10 gig, but they also said that about gigabit, even after the standard that was designed around CAT5 was released, until one of the PHY vendors got sick of hearing about CAT6 and demonstrated gigabit running on

8 strands of barbed wire--that pretty much put an end to the notion that CAT6 was _required_. The actual requirement for 10 gig will not be known until the committee makes an announcement, but odds are that it will be much less stringent in its cable requirements than the cable vendors want it to be.

P802.3an Draft 1.4 discusses the use of Cat 6 cable for distances up to

55 meters, and an "Augmented Cat 6" cable (ISO 11801 Class F) for distances up to 100 meters. There is no mention of Cat 5 for use at 10 Gb/s.

Note: My current cat (my third) is appropriately named Cat-3. I see no reason at this time to upgrade him.

-- Rich Seifert Networks and Communications Consulting 21885 Bear Creek Way (408) 395-5700 Los Gatos, CA 95033 (408) 228-0803 FAX

Send replies to: usenet at richseifert dot com

The usual STP cable is not 100 ohm impedance, so that does tend to decrease the maximum length with 100 ohm termination, and likely with matching termination.

Well, more expensive, yes. UTP cable depends on the signal being balanced. That is, the current in one wire of a pair is exactly equal and in the opposite direction to the other. Transformers are used to make that happen. A shielded cable has metal around the outside of either individual pairs or the whole cable. In either case current in the (inside of) the shield can cancel unbalanced currents from wires inside.

At some point, though, it is possible to get current on the outside of the shield, in which case the shield does not help, and actually radiates the signal. At higher frequencies it gets harder to keep the signal from the outside, and connector design gets very important.

The shield might have to couple to the metal box, and then you have problems with ground loops.

As far as I know, fiber. The cable prices aren't so different, and very likely less than STP cable. Connectors are more expensive, but likely less than STP connectors. Connector installation is more expensive, but again likely less than proper installation of STP connectors.

-- glen

Actually, I'll accept the blame for the following.

Good to have some official word. Any mention of the CAT7 STP that I'm seeing claimed on some of the vendor sites?

I think you may have just named my next one, Momcat Momcatsdottir having recently gone to the Great Catnip Patch without leaving progeny.

Interesting. What sort of connectors? RJ45?

ROTFL! I think over short runs, he performs just as well as Cat-5, Cat-5e, Cat-6 or whatever the vendors will try to sell you.

-- Robert

Thank you for your informations !!!

STP is need in electrically noisy environments. One office I know of was originally cabled with UTP which didn't work, so had to replaced by STP. The office was near wires carring a few gigawatts of electricity.