Implications for Cabling

International Standards Allow Flexibility

Guidance set down by international standards bodies (the main relevant ones are TIA/EIA, ISO/IEC and CENELEC) does not promote one product type over another, but standards do lay down strict criteria with regard to the performance of cables within the network. Standard compliance is determined by the effects that cable and components within the passive network will have on signals at various frequencies. Compliant systems should limit the degree of unwanted signal distortion and noise introduced by the cabling system itself. Key performance criteria on which the industry focuses attention include reducing insertion loss (attenuation) and alien crosstalk. The latter term refers to interference from external sources of noise: shielding is one means of reducing this problem.

Restricted Pockets of Demand for Shielded Cabling

Shielded LAN cables and premises ­wiring systems have traditionally been more popular within some parts of Northern Europe than elsewhere. Demand for fully shielded systems (especially S/FTP or PiMF) has been highest in Germany and Austria. In France users have traditionally favoured partially screened cables (especially F/UTP) to fully screened versions and a broadly similar trend has evolved in Scandinavia. In our chart, the US appears as the second largest S/FTP market, but this is a result of the very large total absolute size of the US LAN cable market: penetration of PiMF in volume terms in the US market is only 1%.

No Strong Conflict Over Shielding

The popularity of U/UTP in most parts of the world can be attributed partly to its lower cost of manufacture, which ultimately benefits the end-user through lower initial cost. Many of the world’s leading LAN cable producers are North American in origin, and some of these have exclusively favoured U/UTP. The rivalry between the U/UTP and S/FTP camps over the years has been relatively light, in the sense that neither party really strayed onto each other’s territory. That is not to say that demand for S/FTP cable has not existed in traditional U/UTP countries, but it has been either sporadic, or restricted to very specific environments. Some cable groups operating in a variety of markets have offered both shielded and unshielded solutions, aiming to meet local market preference.

Higher Performance Opens Up Debate

However, the heightened demand for optimal performance and security management within data centres has triggered a wider debate that has seen ­­­S/FTP solutions come into head-to-head competition with U/UTP solutions. The consensus on guaranteeing optimal performance within both active and passive networks is currently settled on 10 Gigabit Ethernet as its framework. In terms of standards, performance criteria are being set out in relation to ­10GBASE-T. In reference to both unshielded and shielded copper media, the initial corresponding LAN cable specifications were Class E (otherwise referred to as Category 6, defining balanced cabling characteristics over a maximum bandwidth of 250 MHz) and Class F (otherwise referred to as Category 7, defining balanced cabling characteristics over a maximum bandwidth of 600 MHz).

Screened Cables More Secure

Improved security is one benefit that screened cables can generate. In theory, the EM fields emitted by unscreened cables could be detected by suitable equipment and network traffic monitored. Even if the risk is very small, really high security networks may choose to use screened cables or, eliminating any risk of external eavesdropping, use fibre optic cable throughout. In practice, only a few network installations, such as sensitive military operations, have used fibre optic cable for security reasons.

Forcing Change in Supplier Pace

As is typical of the IT sector as a whole, suppliers often seek to differentiate themselves by marketing products that they claim will perform at levels beyond those specified by the industry standards bodies. The suppliers of structured cabling are no different from the rest of the IT industry in this respect. By 2006 many U/UTP and F/UTP LAN cable producers had already launched enhanced versions of their existing Category 6 / Class E designs. This invariably meant that they were launching products at Category 6A / Class EA level, in anticipation of the final standards ratification. The standards body in the US, the TIA, has not yet actually ratified its version of this standard. It is anticipated that this will emerge later in 2007, but the performance parameters are already widely known. Suppliers of PiMF cables have been quick to point out that their products (Category 7 / Class F, offering up to 600 MHz) were already compatible with the emerging standard, and hence no upgraded version would be necessary.

Design Makeover for Cables

One key criticism faced by suppliers of U/UTP cable is that, in their quest to provide the level of performance required for overloaded networks, their enhanced cables have ended up being even bulkier than S/FTP cables, a factor that has been used negatively by the competition over the years. In data centres large numbers of cables may be bundled together in cable trays. To ensure that their products remain attractive to data centre managers struggling to cope with cramming even more products into limited space, several suppliers have come up with SFF (Small Form Factor) cables. This has led to significant reductions in the overall diameters of high bandwidth U/UTP cables.

Initial Muted Reaction From Customers

The structured wiring systems user base has not yet followed the emerging trends in the IT sector. Part of the delay in greater migration to Category 6A has not only been the time it has taken for standards bodies to finalise their guidelines, but also the lack of relevant active equipment. This is already changing, with several equipment suppliers launching server adapters and switch modules specifically for 10Gigabit Ethernet in January 2007. They have conceded that the best approach is to offer attractive pricing to enable the market to move towards mass uptake in as little time as possible, which will ultimately benefit all suppliers competing in this space. This may not initially be sufficient encouragement to gain mass-market appeal. Many customers are still undecided as to whether they actually need to consider 10Gigabit Ethernet, and may prefer to stick at 1Gigabit Ethernet. Using advice from the industry standards bodies, Category 6 / Class E is deemed adequate to meet these needs. Indeed, the ripple effect from the first phase of the 10Gigabit Ethernet debate has been a significant upgrade amongst customers to Category 6.

U/UTP Oriented Suppliers Concede Value of Shielding

Several suppliers, even though they have traditionally offered only U/UTP structured wiring systems, have launched S/FTP products since Q4 2006. Whilst they may continue to place greater emphasis on their U/UTP business, such moves are a reflection of the importance of the debate currently underway. The process guiding this strategy of introducing shielded products may be one of future-proofing through trying to anticipate developments that may occur in a few years time. Thoughts are already turning to the next generation performance level, with references emerging to deployment of 100Gigabit Ethernet, by 2010!

Enhanced Shielding Also Imminent

Suppliers of shielded structured wiring systems are also trying to raise the bar in terms of system performance. They are working in association with standards bodies to establish and ratify a standard for Category 7A. Although the so-called Cat 7A standard is, as yet, some way off full IEEE ratification, it will undoubtedly start to appear more frequently in marketing campaigns. As we understand, the standard will endorse performance at between 900 and 1200 MHz for higher end applications, including Video-on-Demand and multimedia.

Fibre Joins Data Centre Race Also

Fibre optic LAN cables have equally emerged as a strong contender in the context of 10 Gigabit Ethernet and the data centre environment. In countries in which investment in data centres is strong, CRU estimates that demand for such cables represents around 15% of total fibre optic cable demand within the enterprise market sector. Uptake has been strongest within very large data centres, where data traffic has to travel over longer than average distances. This includes data centres owned and managed by Internet Service Providers. In these instances the ability to promote a co-location facility as being fully kitted out with fibre is viewed as a guarantee to attract customers anxious for proof of ultimate network security, in as much as that can be guaranteed.

Fibre Usage Mainly OM3

Unlike copper, the standard for 10Gigabit Ethernet over fibre has been ratified for some time. Although single mode fibre optic cables are sometimes used within the data centre, multimode cables feature more strongly. In particular OM3 multimode fibre with a 50-micron core and enhanced performance, otherwise referred to as Laser Optimized Multimode Fibre (LOMF), is considered to be the highest performer for this environment, even within the riser. 10Gigabit Ethernet performance out to the desktop is not considered an issue over the interim period, outside highly security sensitive environments such as banking and government.