Nexans CAT7A 1200MHz network cableThis short article is our summation of Nexans‘ 40Gb/s (40G) standardisation update bulletin, which reports on the progress of the standardisation of 40Gb/s network speeds. 40Gb/s network speeds is the generation of networking standards for copper-based Ethernet networks, which will then be followed by 100Gb/s; at the time of writing,  there is no formal standard for 40Gb/s networking, where network hardware manufacturers still face the challenge of achieving 40Gb/s speeds.

10 Gb/s

Currently 10 GB/s (10G) is the fastest speed available for copper-based Ethernet networks.  CAT6A cabling systems are accepted to be the minimum standard required to run 10 Gb/s networks.

A number of 10Gb/s hardware products that claim they can run on CAT6 cabling systems, however they do so unreliably, and certainly do not always operate in an optimum fashion. It may be possible to run 10Gb/s reliably on CAT6 if the cable length is fairly short.

CAT6A is a shielded cable with performance to 500MHz, in comparison, CAT6 is typically unshielded and provides performance to 250MHz, some premium CAT6 cables can reach 350MHz.

40Gb/s standardisation update

The noteworthy points from the update are:

  • Category 8 cabling standards will be defined in 2013/2014 by TIA, which is fast tracking this definition.
  • Category6A (CAT6A) network cabling will (likely) not be used for the 40Gb/s standard. It will require very complex network hardware to signal at these speeds. Further more than one CAT6A will be required to run at these speeds.
  • Cat6A or Class EA cabling has insufficient bandwidth even over short distances such as 30m to support 40G
  • Cat7A with its “double frequency range” of 1000MHz could be used for a 40G application.
  • The Cat7A system’s extended frequency range would allow a simplified encoding which might be easier to implement for chip designers.
  • The biggest news for copper cabling is that the 100m distance support has found its end. No cabling system is intended to run 40GBase-T with a link length above the new 30m limit. This new length limitation should be respected in any new data centre layout from now on.
  • ISO describe two new sets of channel performance specifications, both specified up to 2 GHz.
    • The first (Channel I) is similar to the TIA Cat.8 approach.
    • The second (Channel II) is based on an improved version of ISO Class FA and shows a significantly better Signal-to-Noise Ratio.
  • Currently several new specifications to support 40GBase-T are being studied and three of them are based on Cat7A components. Cat.8 or Channel I systems are not on the market yet and therefore cannot be purchased. Cat7A systems even with extended frequency support are available from certain vendors.

Nexans and ISO/IEC

Nexans publish bulletins on the progress of the standardisation of 40Gb/s. Nexans, as cabling manufacturers, are contributors to the formal development and definition of new networking standards to support faster network speeds in IT networks.

Nexans represent cabling manufacturers, who need to develop cables and connectors that will conform to the specifications required by the next generation of network hardware manufacturers, including switches, routers and network adaptors.

Nexans work with ISO/IEC to formally define cabling standards (categories) for the next generation of networks and their high expected speeds.