Issue link: http://www.epageflip.net/i/1043933
November/December 2018 I 9 When thinking about a star topology, one imagines the usual building distributor (BD) on the ground floor and then a floor distributor (FD) on every floor. This is the case for most installations and has proven to be efficient and reliable, but it also has the following shortcomings: • The telecommunications room (TR): when designed, it is always perfect, with plenty of space and perfect cord management in the racks. But after installation, due to various time and space constraints, the result can sometimes be far from expectations (e.g., the typical mess of spaghetti). • The pathways: per standards and in theory, they are designed for maximum 40% fill ratio, but when changes are made, they rapidly fill. • Changes: with long cables in the ceilings, moves, adds and changes (MACs) can lead to significant disruptions and costs. Consolidation points (CPs) and multi-user telecommunications outlet assemblies (MUTOAs) can improve this by providing local cabling management. • Fire risks: more cables imply more plastic material and consequently more fuel in case of fire. The long cable lengths often crossing fire barriers require firestops, which risk being forgotten during MACs. • Power efficiency: the maximum 90 m cable length is generally used to design a minimum of TRs that use up space and increase costs. However, with PoE applications, longer length also means higher resistance and lower power efficiency. The worst-case scenario with maximum power, maximum length and lowest category cable could imply up to 25% waste of energy! FIGURE 2: Traditional star topology designed with 5 floors, each with 48 dual outlets. The Traditional Star Topology: 48 dual outlets Cabinet 42u equipped with: ○ 1x Fiber panel 12-cores ○ 4x Patch panel 24 ports ○ 2x Switch 48 ports Gigabit 12-core fiber cables to each of 5 FDs Cabinet for BD equipped with: ○ 1x Fiber panel 5x 12-cores ○ 1x Switch 6 ports Fiber Typical Floor F D B D To other 4 FDs 96 cables Corridor Office area Work area