What is the minimum acceptable (industry recognized standard) cable length for cat 5, E, and Cat 6 cable types in these two instances:

Between transmission mediums (i.e. switch to switch)

From transmission medium to patch panel

Can anyone quote a specific preferably BICSI  standard for this?

I've seen many people say 3 ft is acceptable for switch to switch, and 1 ft is acceptable to the patch panel. The problem is I can't find a specific standard for this. I would very much like to quote a published regulation. This seems trivial, but it's been a pain in my neck for a couple years now.

Any help is appreciated.

Hope this helps!

Chapter 4 – Page 80 TDMM 11 Edition

Length Requirements

HC (FD) jumpers and patch cords should not exceed a length of 5 m (16 ft) per link. System

designers should plan for a combined cable length of 10 m (33 ft) for patch cords and

equipment connections in the work area and TR or TE. This length is in addition to the 90 m

(295 ft) of cable allowed between the HC (FD) and the telecommunications outlet/connecter.

Chapter 5 – Page 20 TDMM 11 Edition

Equipment Cable Length Limitation

The length of the equipment cable used to connect telecommunications equipment directly to

the MC (CD) or IC (BD) should not exceed 30 m (98 ft).

Chapter 6 – Page 18 TDMM 11 Edition

Cross-connect fields, patch panels, and active equipment in the telecommunications space

must be placed to allow cross-connections and interconnections via jumpers, patch cords, and

equipment cables whose lengths per channel do not exceed:

• 5 m (16 ft) for patch cords or jumpers in the horizontal cross-connect (HC [floor

distributor (FD)]).

• 10 m (33 ft) total, for patch cords/jumpers, equipment cables connected to the HC (FD),

plus the work area cord.

• 20 m (66 ft) for patch cords or jumpers that serve main cross-connect (MC [campus

distributor (CD)] or intermediate cross-connect (IC [building distributor (BD)]).

Ron Leger, RCDD, TPM, CFOS

rleger@mcacom.com

Dusty,

Ease up the pain in your neck. As far as I know, there is NOT a "standard" or "published regulation" for minimum length of a patch or equipment cord from either from BISCI or the EIA/TIA. The next best thing is to go to the manufacturer of the equipment for their standards and/or recommendations.

Joseph Golan, RCDD (Retired)

Palm Coast, FL

For Category 5e and 6, there is no minimum length requirement. ANSI/TIA/EIA-568-B.2-1 in Annex K does give a warning about reflected FEXT on shorter links with minimally compliant components. The obvious solution is not to purchase minimally compliant components. In the early days of Cat 6 when vendors were struggling to do better than marginally compliant, short links were an issue. Today, this is not an issue if you stay with a main stream vendor.

Within this same standard, there is also advice on distance when using a consolidation point. It advises a minimum distance of 5 m between the CP and TO. In ISO/IEC they are a little more clearer is specifying 15 m between the DP and CP. This is all for Category 6/Class E.

With regards to Category 6A, there is a minimum length requirement - kind of. In Annex J of ANSI/TIA-568-B.2-10 is describes worst case modeling using a 10 m link. The suggestion therefore is that you should not go less than 10 m. But again, that is with minimally compliant components. As with Category 6 stated above, there are now components available that will give you passing field tests below 10 m. HOWEVER, even vendors with good components may still have a minimum length requirement in their design specifications. The only way to know where you stand is to talk to the vendor AND test it to see.

If you are talking specifically about patch cords, then 0.5 m is the implied minimum length in ANSI/TIA/EIA-568-B.2-1 for a certified patch cord. That's because the math for the limit lines really does not work below this. Infact, getting a certified patch cord of 0.5 is going to be tricky. Many vendors only offer a certified patch cord of 1.0 m or longer. I suspect that this may be the most useful information with regards to your question.

Kind regards

Adrian Young
Sr. Customer Support Engineer

Fluke Networks Technical Assistance Center
6920 Seaway Blvd, Everett, WA 98203
Toll Free 1 800 283 5853
International + 1 425 446 4519

Are you current with your software?

 - DTX Version 2.12
 - LinkWare Version 5.0 (New NOV 08)
 - AxTalk Analyzer Version 3.0
 - OptiFiber Version 2.2.1
 - CableIQ Reporter 1.31
 - CableIQ Version 1.3
 - DSP Version x.925

http://www.flukenetworks.com/fnet/en-us/supportAndDownloads

Kind regards

Adrian Young
Senior Technical Support Engineer
Fluke Networks Technical Assistance Center

You can test short Cat 6A links, if you've installed the right connector. This video explains why.

As always a great reply and on target.

BTW what is different in the new version of Linkware. I could find a readme file listing the reasons and a summary of any new features, etc.

Joseph Golan, RCDD (Retired)

Palm Coast, FL

IMO, no. In our documents, we refer to "BICSI Guidelines."

What does everyone else think?

Doug

Doug Weis, RCDD, ESS

doug.weis@hei-eng.com

There is a difference between code and standard.  Codes protects person and property as standards protects performance.

BICSI is an accredited body and has jointly developed standards.

Kevin J

 

A picture is worth a thousand words. 

I guess I need to PDF it as well and put it in the download pages.

http://www.flukenetworks.com/fnet/en-us/supportAndDownloads/KB/Datacom+Cabling/linkware/Release+notes+for+LinkWare.htm

Adrian

Kind regards

Adrian Young
Senior Technical Support Engineer
Fluke Networks Technical Assistance Center

You can test short Cat 6A links, if you've installed the right connector. This video explains why.

So I checked with my standards guy. BICSI is an ANSI accredited standards body. They have standards. However, it is incorrect to refer to the TDM as a standard which sometimes happens.

Kind regards

Adrian Young
Senior Technical Support Engineer
Fluke Networks Technical Assistance Center

You can test short Cat 6A links, if you've installed the right connector. This video explains why.