THE NEW TIA/EIA 568B FREE cabling and networking Helpdesk
 Question by DAVID POWERS posted 20 Mar 2001
I was hoping that you could help me, I am looking for information on the new version of the TIA/EIA 568B standard That is support to eliminate category 5. Any information would be greatly appreciated.
 Answer by Roman Kitaev posted 21 Mar 2001
Hi, David!

The new 568B standard consists of three parts:

TIA/EIA-568-B1 "Commercial Building Telecommunications Cabling Standard Part1: General Requirements";
TIA/EIA-568-B2 “100 Ohm Balanced Twisted-Pair Cabling Standard”;
TIA/EIA-568-B3 "Optical Fiber Cabling Components Standard“.

Only the 568-B3 part was approved in April 2000. It is expected that the other parts will be approved this year.

The most important differences between the 568A and 568B standards are as follows:

The 568-B standard has incorporated many additional Telecommunications Systems Bulletins (TSBs) and Addenda to the 568-A:

TIA/EIA TSB67 “Transmission Performance Specifications for Field Testing of Unshielded Twisted-Pair Cabling Systems”
TIA/EIA TSB72 “Centralized Optical Fiber Cabling Guidelines”
TIA/EIA TSB75 “Additional Horizontal Cabling Practices for Open Offices”
ANSI/TIA/EIA-568-A-1 “Delay & Delay Skew”
ANSI/TIA/EIA-568-A-2 “Misc. changes”
ANSI/TIA/EIA-568-A-3 “Hybrid and Bundled Cables”
ANSI/TIA/EIA-568-A-4 “Patch Cords”
ANSI/TIA/EIA-568-A-5 “Category 5E”
TIA/EIA/IS-729 “Technical Specifications for 100 Ohm Screened Twisted-Pair Cabling”

Performance specifications for Category 5e balanced 100 Ohm cabling have been included.

150 Ohm shielded twisted-pair cable (STP/A) was deleted from the list of cables “recognized and recommended for use in the horizontal cabling system”. It is a recognized media, but not recommended for new installations.

50/125 two-fiber multimode optical fiber cable has been added to the list of cables “recognized and recommended for use in the horizontal cabling system”.

Minimum transmissions requirement in the horizontal cabling is now Category 5e cabling. Category 5 will not be supported and serves as an informative section of the 568B.

Each work area shall have a minimum of two outlets:
One outlet supported by 4-pair 100 Ohm cable, Category 3 or higher (Category 5E is recommended)
The second outlet by one of the following media: 4-pair 100 Ohm Category 5e cable; two-fiber multimode optical fiber cable (62.5 or 50)

Performance specifications have been provided for 50/125 optical fiber and cables.

Alternate fiber connector designs have been allowed in addition to the SC connector.

The term “telecommunications closet” has been replaced with the term “telecommunications room”

As soon as Category 6 cabling performance specifications are agreed, they will be added to the 568B-2 as an Addendum 568-B-2.1

Best regards
Roman Kitaev, RCDD

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