40GBASE-T – A Quantum Leap Forward for Data Centers

R&M: Unbeatable economic advantages expected from new standard / Copper lines soon to handle speeds of 40 Gigabit over 30 meters / R&M is working on metrology for Cat. 8 / Warns against hasty decisions ahead of finalized standards

Wetzikon, June, 26, 2013

R&M, the Swiss specialist for network cabling solutions, sees huge market potential in the future 40GBASE‑T standard. The company gives correspondingly high priority to the development of suitable copper cabling solutions for Cat. 8, the coming generation of connection technology for high-performance data networks. However, R&M warns the data center market in particular against premature investments as long as the standards are not defined and appropriate components are not fully developed


Cost per link, normalized to a connection with direct-attach cables (= 1). The estimate shows that 40GBASE-T is economically unbeatable for link lengths up to 30 meters.
Graphics: R&M

Thomas Wellinger, Market Manager Data Centers at R&M: "We are convinced 40GBASE-T will be a great success even though 10GBASE-T is still waiting for its big breakthrough." The respective cabling systems are meant to close the gap between classic copper cabling for 1 to 10 Gigabit Ethernet and fiber optic cabling. Thomas Wellinger added that the market cannot ignore 40GBASE-T. Its economic potential is simply too significant judging from current R&M market observations and experience with millions of installations for its own high-end Cat. 6A and fiber optic solutions (diagram 1).

While 10GBASE-T was defined for general applications, 40GBASE-T is intended for use directly in data centers. With a range of 30 meters, the future standard closes the gap between direct-attach cables 7 or 15 meters long for intra-rack cabling and structured fiber cabling with a range of up to 150 meters. An inexpensive copper alternative capable of carrying greater data volumes more quickly than before is therefore needed for structured cabling over medium distances, e.g. between cabinets in an aisle in a computer room. The expectation at R&M is as follows: "The field of cabling providers offering well-functioning solutions will thin out due to the technical complexity involved, regardless of what the standardized requirements end up being."

Standards just now coming into being

The cabling standard ANSI/TIA-568-C.2-1, "Specifications for 100Ω Category 8 Cabling", is now coming into being parallel to the work of the international standardization organization IEEE on 40GBASE-T. At the same time, consultations are underway at the ISO/IEC organization about launching the forward-looking categories Cat. 8.1 and Cat. 8.2. The frequency range has not yet been set but it is expected to be 1.6 to 2 GHz from today's perspective.

Many questions remain unanswered in the standardization process: Will S/FTP be the cable of choice? Which frequency range will be adopted? etc. IEEE has not yet even specified many parameters such as TCL. The abbreviation TCL stands for "transverse conversion loss" and describes the ground symmetry loss of symmetrical wire pairs. It measures sensitivity to noise coupling. R&M emphasizes that the specification of TCL will greatly influence the design of cables for 40GBASE-T.

The company is leading the way within important standardization bodies in the development of connectivity for 40GBASE-T, including the following among others, IEC-TC46 (cables), IEC-TC48 (connectors) and ISO/IEC JTC1 SC25 (infrastructure). R&M supports the activities of these organizations with its own research and development work.

Metrology still to be developed


Example of a Cat. 8 measurement in the R&M lab involving prototypes of the next generation of connection equipment.
Graphics: R&M

One crucial prerequisite for the introduction of 40GBASE-T and the specification of the appropriate components is suitable metrology. Up until now, many parameters have only been able to be measured in elaborate procedures in labs, if at all. Top manufacturers of measuring equipment are therefore cooperating with R&M and jointly promoting the necessary research and development work. "Measuring equipment manufacturers depend on the expertise of the R&M Laboratory in the field of high-frequency signal transmission over twisted-pair copper cables," Thomas Wellinger explains (diagram 2).

What lies ahead?

Work on the implementation of 40GBASE-T has only just begun. IEEE has set an ambitious goal of publishing the standard in 2016 because of the tremendous commercial interest involved. The advantage 40GBASE-T offers in terms of speed and data volume plus the cost advantages of twisted-pair cables for medium link lengths will outclass the entire previous performance of copper cabling in data centers. "That is why R&M is so convinced that 40GBASE-T has to be developed," the R&M Market Manager Data Centers explains.

However, R&M warns against premature expectations and hasty decisions. The connection and cabling technology for 40GBASE-T / Cat. 8 is extremely complex. Only solutions that are truly technically mature and inherently consistent and compatible should be marketed. Until then the rule of thumb will be: The longest service life for cabling will be attained with the best solutions currently available, not with future solutions.