test equipment & tools
SPECIAL FEATURE
Best of both
With regards to the debate between copper and fibre , Ed Gastle at Viavi Solutions argues that both technologies have a place in today ’ s data centre infrastructure . However , certification of installations and ensuring best practices are vital .
Data centres are at the nexus of several major networking and information technology shifts . These include : the continued explosion in demand for bandwidth ; the changing nature of traffic - from large individual streams with tolerance for latency , to exponentially more lowbandwidth streams from the Internet of Things ( IoT ); the normalisation of hybrid IT ; and a decline in the cost of maturing technology .
Room for both ?
Traditionally , fibre has been considered superior to copper for use in cabling infrastructure , especially given the scale of changes just described . However , there are clear trade-offs between the two media , with fibre being costlier and more complex to install , and copper being more limited in capacity and range . With recent developments in copper cabling standards , and as data centre topologies evolve , there should be room for both technologies . Regardless of
MTS2000 : Technicians benefit from tools that give them complete visibility of an entire link , with every event in a single view . the technology under discussion , the correct certification of installations is vital . Following are some considerations and best practices in these areas .
Copper installation
Specifications for the next generation of copper cabling , called Category 8 , were approved by TIA TR-42 Telecommunications Cabling Systems Engineering Committee in June . ISO / IEC has also circulated a final version for review and comment . These complementary standards address balanced twisted-pair cabling supporting 25G and 40G Base-T interfaces , over a length up to 30m and frequency up to 2GHz . With these attributes , copper becomes significantly more relevant in data centre applications , especially for rack-level interconnect or in topologies such as leaf-spine . It will no longer be necessary to make a blanket trade-off between copper and fibre , but rather utilise each where it is a better fit with respect to capacity , range , cost and ease of deployment .
Testing multi-fibre connectors requires visibility to the performance of each individual fibre in a single connector .
With Category 8 being so new , not all tools may be immediately standard compliant , especially when it comes to testing up to 2GHz , two to four times the frequency range of the previous standards . It is essential for data centre managers and installers to be diligent in assessing inspection and test instruments to ensure compliance .
Fibre installation
Fibre and associated test and certification standards have been around in their current form since 2011 , so there is significantly more to discuss . The four key factors in installation and certification are : end-face inspection ; encircled flux for multimode sources ; use of test reference cords ; setting and performing test references .
1 . End-face inspection When two fibres are mated together , there are three key requirements to ensure light passes from fibre to fibre without excessive loss or back reflections . Today ’ s connector design and production techniques have eliminated most of the obstacles to achieving core alignment and physical contact . What remains challenging is maintaining a pristine end-face . A single particle mated into the core of a fibre can cause significant insertion loss , back reflection , and even equipment damage .
As a result of this the condition of fibre end-faces is potentially the single most controllable factor for the consistency of loss results as well as the ability for a system to perform as designed .
This impacts all industries that use fibre optics , not just enterprise and data centre networks . In an effort to guarantee a common level of performance from optical connections , the IEC developed Standard 61300-3- 35 that specifies pass / fail requirements for end-face quality before connection .
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