Is an Augmented Cat 6 Cabling Package Coming?

This package is coming—maybe not this holiday season, but probably after the next one. It may be broken up into three smaller packages, but here is a look at what is going to be included:

• TSB 155

• Addendum 10 to TIA 568-B.2

• Addendum 11 to TIA 568-B.2

Now, somehow, all three are related. When looked at individually, their interrelationship shows strong and clear.

TSB (Telecommunications Systems Bulletin) 155 “Guidance for Field Testing Installed Cabling for 10GBASE-T” for 10 gig Ethernet transmission over 55 meters of existing Category 6 cabling

PURPOSE: To respond to IEEE 802.3’s request for more guidance on how to get 10 gigabit Ethernet transmission over a company’s existing Category 6 infrastructure. This TSB gives more installation guidelines in addition to those already covered in the first Category 6 cabling standard—TIA-568-B.2.1 “Transmission Performance Specs for 4-pair 100 Ohm Category 6 Cabling.” This TSB is for the “extended frequency” transmission performance of a Category 6 cabling system—that extended frequency range is from 250 MHz up to 625 MHz. This is where the alien NEXT (cross talk or the unwanted signal coupling between pairs in adjacent cabling or components) is described and field testing covered.

TESTING SET UP: This may look familiar to many, but it shows the test configurations used by designers to verify the performance of the overall channel and permanent link.

SPECS FOR TESTING: When completed, this TSB will give specs that need to be tested for the frequencies up to 625 MHz. Take a look at how those specs break out:

Permanent link and channel IL (insertion loss)

For a channel length of 55 meters for 10 gig Ethernet

For a permanent link of “x” meters for 10 gig Ethernet

NEXT (near-end cross talk) loss

For a channel length of 55 meters for 10 gig Ethernet (as in 568-B.2-1)

Power sum NEXT loss (PSNEXT)

For a channel at frequencies from 1–250 MHz (as in 568-B.2-1)

For a channel at frequencies from 250–330 MHz

For a channel at frequencies from 330–625 MHz

Equal level FEXT (far-end cross talk) loss (ELFEXT) and FEXT loss

For a channel at frequencies from 1–250 MHz (as in 568-B.2-1)

For a channel at frequencies from 250–625 MHz

For a permanent link from 1–250 MHz (as in 568-B.2-1)

For a permanent link from 250–625 MHz

Power sum ELFEXT (equal level far-end cross talk) loss

For a channel at frequencies from 1–250 MHz (as in 568-B.2-1)

For a permanent link from 250–625 MHz

Alien NEXT (near-end cross talk) loss

(Measure of unwanted signal occuring between pairs in adjacent cabling from transmitters at near-end into a pair measured at the near-end.) Specs will be for a channel of 55 meters

RL (return loss)

Propagation delay/delay skew

(Time it takes for a signal to travel from one end to the other).

There are also three annexes planned that will cover:

• Field measurement procedures • Test instruments • Alien cross talk procedures for improvement

Since this is a TSB and not a formal standard, it can be handled internally and then issued when finished to the public as guidance. This has now been approved as Draft 1.0 with more work to be done on it.

Addendum 10 to TIA-568-B.2, “Transmission Performance Specifications for 4-pair 100 Ohm Augmented Category 6 Cabling” for 10 gig Ethernet transmission over 100 meters of ‘augmented’ Category 6 cabling

PURPOSE: This new standard, added onto other Category 6 cabling work, is being developed because cabling designers need to have a way to control alien crosstalk noise that is harmful to 10 gigabit Ethernet transmission at the 100-meter distance. The current feeling is that the way to ‘control’ this AXT (alien NEXT) is through the configuration and installation practices.

TESTING SET UP: These test configurations have not been agreed to yet—either for the cabling or for the components. In fact, the “recognized” cable (for the horizontal) has not been made known yet. The content will cover test configurations, components and cable, and connecting hardware tests.

SPECS FOR TESTING: Tests (up to the ‘extended’ frequency of 625 MHz) will be spelled out for Insertion Loss, NEXT (Near End Cross Talk) Loss, ELFEXT (Equal Level Far End Cross Talk) Loss, FEXT (Far End Cross Talk) Loss, Return Loss, Propagation Delay/Delay Skew, Balance, and the much-debated Alien Crosstalk Loss.

Some of the test calculation data has been collected but will be reworked to ensure it is error-free. The committee did agree to contact the committee that developed Ethernet to let them know of the work done so far and to request 802.3an (for 10 gigabit Ethernet over copper) adopt “augmented” Category 6 cabling as a media objective. The plan was for this media standard to achieve approval when 802.3an (10GBASE-T) standard does in 2006.

Addendum 11 to TIA 568-B.2 covering specifications for an increased UTP and ScTP cable diameter (allowing an increase in outer diameter to 0.31 inches from 0.25 inches).

PURPOSE: This standard was started to enable the continuance of work on “augmented” Category 6 cabling (Addendum 10 previously mentioned). A special task group was assigned to determine if a larger outside diameter of .310 inches would affect UTP or ScTP hardware associated with horizontal cabling. The plan was to revise the section of TIA 568-B.2 on cable diameter to state the diameter of the completed cable shall be less than 0.31 inches, versus shall be less than 0.25 inches.

The reason this relates to the “augmented” Category 6 cable is because that cable will probably have a larger OD, due to its internal design that will handle alien cross talk. Watch after October 2004 to see how this addendum develops once the industry gets a chance to comment on it. There have already been comments made about connectors having some problems with this design.

Guidance for the Contractor

In current trade articles, there has been plenty of talk about who’s building what to handle 10 gigabit Ethernet. It seems, for one thing, that the networking gear manufacturers who have already made this available to their large customers also want to make this available for the smaller corporate customer. If they can put this faster technology on less-expensive equipment, the more affordable 10 gigabit Ethernet uplinks that provide 10 times more capacity than regular gigabit Ethernet can be used not only for the large corporations that build supercomputers, high-end data centers and storage area networks, but also using this technology over copper cable can offer an alternative to the fiber InfiniBand technology or Fibre Channel switches for the smaller business. These manufacturers can get the smaller customer into higher bandwidth technology.

Although costly at first, prices are falling and as equipment manufacturers see the opportunity, they may then extend this technology to their lower-cost products. The future direction for 10 gigabit Ethernet could cover from the large corporate customer to the small and midsize business.

Point One

Watching the development of these high-performance 10 gigabit cabling solutions will be important. It has clearly been said to me that the customer feels more comfortable when they know there is an approved standard that exists, before they put in a new technology. If you know how this is evolving and what it really means, you will be ahead of others in the business. You may have customers who need the increased bandwidth to support their research and development work.

Point Two

If a company’s cabling system is the most difficult element of the network to upgrade and customers want it to last for five to 10 years (which is quite a bit longer than the life of active network equipment), then being able to offer them your expertise in the area of installing a high quality, high performing cabling system should go a long way toward putting you ahead in this industry. EC

MICHELSON, president of Jackson, Calif.-based Business Communication Services and publisher of the BCS Reports, is an expert in TIA/EIA performance standards. Contact her at or


About the Author

Marilyn Michelson

Freelance Writer
Marilyn Michelson, president of Jackson, Calif.-based Business Communication Services and publisher of the BCS Reports, is an expert in TIA/EIA performance standards.

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