40GBase-T promises excitement
In December we reported on some of the initial efforts by the Telecommunications Industry Association (TIA) to produce ...
by Patrick McLaughlin
In December we reported on some of the initial efforts by the Telecommunications Industry Association (TIA) to produce a set of Category 8 twisted-pair cabling specifications for the support of 40GBase-T (see “TIA working on Category 8 standard,” December 2012). The TIA group working on the Category 8 specifications has ambitious plans concerning the amount of progress it expects to make in 2013.
If you are inclined to read and/or contribute to industry-related discussion groups, you may already have seen some of the technopolitical debates taking shape around the Category 8 specifications. In large part these debates concern the TIA’s decision to move ahead with a Category 8 specification independent of the ISO/IEC’s Category 7 and 7A specifications, and the likelihood that the Category 8 requirements for some electrical-performance characteristics will be less-strict than those of Category 7A for the same characteristics. We mentioned this in our December reporting as well, but as you might imagine the topic has taken on a life of its own in the aforementioned discussion groups.
For me there is a bottom line to the discussion/debate. It’s the bottom line for me because it’s what I honestly believe matters the most to you as readers of this publication. And that is: Will a cabling system that complies with the specifications support the intended application? In this case, it’s: Will a Category 8-compliant system support 40GBase-T?
The development of Category 8 is in keeping with the successful efforts through which a set of cabling-performance parameters is developed in tandem with an Ethernet transmission protocol. By contrast and for example, the TIA’s development of Category 6 was not in sync with an IEEE effort to develop 1000Base-TX (i.e. Gigabit Ethernet over two copper pairs). The IEEE passed on a 1000Base-TX project and the TIA’s own efforts to put forth 1000Base-TX fell flat. Category 6A, on the other hand, aligned that cabling-performance level with 10GBase-T.
No one has ever told me that the TIA passed on opportunities to construct a Category 7 or 7A set of specifications because there was no direct alignment with an Ethernet protocol. But the TIA’s actions, in the form of its decision to move forth with a 40GBase-T-aligned Category 8, make a statement.
The issue of Category 8’s backward-compatibility with Category 7A remains unsolved as of today. Look for upates here, and in those juicy discussion forums, in the months ahead. ::