TechArchive

Original article date: June 2000

With the amount of data being carried over the internet doubling every 100 days, what are the implications for networking enclosures, reflects APW’s MARCUS EDWARDS.

Appropriate cable management is the key to any high performance network. Ever-higher bandwidths are being achieved in copper cabling with the development of Categories 5, 5e, 6 and 7; fibre is being increasingly used in the horizontal as well as the vertical, with FTTD now a realistic, cost-effective option.

From its humble beginnings as a passive carrier with no effect on the network’s bandwidth, the structured cabling LAN has become an increasingly important element of the total system as bandwidths and frequencies have increased. The cabinets and enclosures – the areas of highest concentration of discontinuities within the network – have themselves become essential components because improper cable management will degrade the performance of a network using copper media. Performance degradation is significant in faster systems, such as fast Ethernet and ATM, where the bandwidth is 100Mb/s or higher. And with Gigabit Ethernet now a reality, even 100Mb/s is beginning to appear pedestrian.

The new IMnet and IMserv networking cabinets are the latest developments in a long line of rack and cabinets to be introduced by APW Electronics. As well as the demonstrable technical benefits, there are direct cost savings of 25% in the cost of the enclosure itself, further direct cost savings during installation and indirect savings to be gained through improved network reliability and decreased outages caused by physical layer faults.

The designs of the IMserv and IMnet top and bottom frames are based on a curved ‘X’ shape, giving good strength and rigidity and, most importantly, providing three places where cables can be dropped into the enclosure without having to thread them through apertures. Space for cable runs is maximised and, in bayed suites, cables can run vertically between cabinets, breaking out into the enclosure as required. The front verticals are recessed, enabling simple front patching between cabinets.

Segmented cable channel

All verticals accept both ETSI and 19in panel mountings; the 19in versions provide a 50mm wide segmented cable channel on one side of the 19in area in a 600mm wide unit. In an 800mm wide rack, there are 125mm wide cable management areas on both sides of the 19in rack mounting. Additional external 100mm cable housings can be mounted on one or both sides of the cabinet for heavy cabling density applications, and all accessories and cross members feature cable management facilities, rounded tops for cable guidance and clip into place without tools. In bayed suites, cables can be run between racks in front of the recessed verticals, and again, the inter-rack cables can be laid into the enclosures.

In both products, cables can be laid into the cabinet through three separate apertures in the top, doing away with the need to thread cables through frames. Cable runs can be positioned first, with the cabinet then being offered up and the breakouts into the cabinet connected, saving installation time.

Looking ahead, in the immediate future the differences between the needs of the patching/cabling enclosure and the server housing will continue to diverge. Already there are a number of 1U high, multi-processor servers on the market; the trend towards far greater distribution of computing power within the network is already evident. Instead of one central server, the trend is towards multiple workgroup servers and their associated hubs and routers, located at strategic points throughout the organisation. Already, application-specific servers are a reality: web servers, e-mail servers, CAD servers and so on will all co-exist and inter-operate across the network. The server housings will have to cope with physically larger equipment, so increased depths are required; higher packaging densities require more effective thermal management, and as most equipment has rear power and cable entry, the enclosure must provide access to the rear of the units for reconfiguration and upgrading. More equipment inevitably leads to more cabling, so cable management, even in server racks, becomes more significant. The server housing is becoming increasingly integrated into the LAN, with environmental and security monitoring already an established feature: this trend is bound to continue.

• APW Electronics

June 2000