Vol. 5 - Sept-Oct 2017 Edition

Practical Applications for Category 8

Category 8 cabling solutions have arrived, with the ability to support new 25/40GBASE-T networks. It’s impressive that the same tried-and-tested twisted pair cabling and RJ-45 interface that delivered 10 megabits per second 15 years ago still play an important role in next generation networks.

But what are the practical applications for Cat 8? Where will it be deployed? First of all, these cabling systems make sense for applications requiring speeds greater than 10 Gb/s. This goes beyond the capabilities of Cat 6A, which has the performance specifications and flexibility to handle 10 Gb/s or slower speeds.

Also, for now, Cat 8 cabling systems will be limited to the access layer in data centre networks. Due to its distance limitations of 30 metres or less in a two-connector channel — per IEEE, ISO, and TIA standards — Cat 8 cabling really isn’t applicable for enterprise or premise networks. However, for data centre managers, Cat 8 offers some huge benefits. When planning for networks greater than 10 Gb/s in the access layer, the decision of which cable type to use largely depends on the network topology you prefer: Top-of-Rack (ToR), End-of-Row (EoR), or Middle-of-Row (MoR). Cat 8 will be able to support all of these topologies.

Cabling for Top-of-Rack

If you prefer a ToR topology, you now have a choice between Direct Attach Copper (DAC) or Cat 8 for copper infrastructure. The ToR model uses a simplified cabling scheme — short intra-rack cable runs with a small number of uplinks to the aggregate switches.

Quad small form-factor pluggable (QSFP+) DAC passive assemblies were standardised in 2010 through IEEE 802.3ba. They are low-power solutions and have a similar form-factor to SFP+ 10 Gb/s (and future 25 Gb/s) assemblies. However, they have a limited distance of up to seven metres. With such limited reach, they are a better fit for ToR topologies instead of longer distances used in other topologies. QSFP+ DAC assemblies are also not backwards compatible, and can be used for 40 Gb/s networks only.

Unlike DAC assemblies, Cat 8 cabling leverages the benefits of auto-negotiation. Auto-negotiation allows for two Ethernet devices to connect to each other and select a common transmission speed that both devices support. Auto-negotiation requirements are laid out in IEEE 802.3 BASE-T standards. For example, 25 Gb/s ToR switches can communicate with 10Gb/s servers, whether over Cat 8 or Cat 6A connectivity.

This also allows for network migration to 25/40GBASE-T to be done in phases, allowing for more flexibility in terms of timing, disruption, and cost. With staggered active gear upgrades, BASE-T solutions can allow for mixed server speeds in each rack or cabinet supporting any combination of 1, 2.5, 5, or 10, 25, or 40 Gb/s servers, creating better port utilisation of the switches.

Cabling for End-of-Row and Middle-of-Row

EoR and MoR designs have every server cabled back to a single switch dedicated to a row of server racks. The upside of this structured cabling approach is a simplified management environment with just one switch to manage per row.

These topologies require longer links than those for ToR designs, and for 25 and 40 Gb/s networks in EoR and MoR topologies, your two options are to use Cat 8 or multimode fibre. The longer cabling requirements eliminate short-length DAC assemblies as an option.

Multimode fibre offers the benefit of working over longer distances and low power, and it can provide a smaller cable profile. However, the high costs of fibre active equipment makes it an option that not all end users can justify.

Category 8 can support the longer distances required in EoR and MoR designs, but it is limited to 30 metres or less. However, according to IEEE, links of 30 metres or less make up 80 percent of data centre connections in the industry. If you require longer distances, fibre is the only option. Cat 8 also offers the benefit of operating over low power: it will not likely require any greater power or cooling requirements than a typical 10GBASE-T system used today.

Even if Cat 8 is not part of your immediate data centre strategy, you may want to anticipiate future tech refreshes in your current network infrastructure design. This means considering cable distances, connection counts, shielding, and more. Preparing for Cat 8 now will create a simple and cost effective migration in the future.

Brand-Rex Leads with Atlas-X1

Altas-X1 Cat 8 connectivity uses the same form factor and termination methods as other Atlas-X1 jacks. In fact, Atlas-X1 is the industry's first system to support shielded applications from Cat 5e to 8 and UTP applications from Cat 5e to 6A, all from one unified connectivity platform. Also, our Atlas-X1 Cat 8 Shielded Cable is independently tested and verified to meet ISO 11801 Class I performance standards, and complies with EN 50575 Euroclass B2ca.

Atlas-X1 system components are proudly made in the United States and the United Kingdom, and they deliver the highest level of verified performance across all categories to seamlessly support network migration up to 40GBASE-T. To learn more about Atlas-X1, go to www.Brand-Rex.com/products/copper-systems/atlas-x1.

Cloud vs Enterprise Data Centre Networks

Data centres are rapidly evolving to address rising volumes of network traffic. Faced with demands for higher bandwidth and the need to adapt and scale quickly, many organisations with small or medium data centres have moved to cloud service providers or have outsourced to colocation facilities. Also, many large enterprise data centres with traditional three-tier architectures are moving to “flatter” leaf-spine architectures, creating lower latency and more scalable designs.

As these data centres adapt, one trend is clear: while both cloud data centres and enterprise data centres invest heavily in next-generation network infrastructure, they follow diverging migration paths, as they deploy different types of optics, network speeds, and cabling systems.

Trends in Network Speeds

Today, while 10 Gb/s transceiver modules make up a large portion of the market, 100 Gb/s is starting to make a big move, driven largely by cloud environments. By 2018, eight speeds will be available on the market, including 200 and 400 Gb/s, creating an unprecedented number of options for data centre managers to evaluate and design their networks to support.

Narrowing to transceiver trends at 25 Gb/s or faster, the figure below from LightCounting shows how 40 Gb/s adoption will begin to flatten in the next two years. Interestingly, 25 Gb/s transceiver shipments will grow in parallel with 100 Gb/s. These two rates are related, and their parallel growth is largely the result of the 2015 IEEE802.3bm standard defining 100G-SR4, which allows for 100 Gb/s using four 25 Gb/s lanes over an 8-fibre MTP® connection.

These 25 Gb/s lanes enable the next wave of high-speed networking, as more data centre tech refreshes will include 100 Gb/s uplinks at the switch and 25Gb/s down to the server. The majority of these lanes – around 75 percent – will use 4-fibre or 8-fibre MPO/MTP connections for short-reach applications at 500 meters or less. Long-reach applications over single-mode largely use an LC interface over two fibres.

Current enterprise data centres primarily use 10 Gb/s switches and 1 Gb/s servers. These networks are migrating to 25 or 40 Gb/s uplinks and 10 Gb/s servers. The majority of enterprise data centres already have multimode cabling installed, and 85% of these optic links are 150 meters or less.

The migration path for enterprise data centres will take advantage of existing multimode cabling while moving to 10, 40, and 100 Gb/s in the future. With over 12 different 40 Gb/s transceiver options and 10 different 100 Gb/s transceiver options available on the market, infrastructure engineers must design their networks to be flexible and able to support any of these potential topologies.

Cloud Provider Network Migration

Cloud networks have operated at 40 Gb/s uplinks and 10 Gb/s at the server for the past several years. These networks will move to 100 Gb/s uplinks and 25 Gb/s at the server in the near future. We can also expect future migrations to 200 and 400 Gb/s uplinks and 50 and 100 Gb/s at the server. When comparing optical fibre systems for these higher speeds, cloud service providers are increasingly adopting single-mode over multimode systems.

In 2016, Microsoft Azure, a market leader in cloud services, moved the vast majority of its data centre fibre cabling to single-mode. In fact, Microsoft is now 99 percent single-mode, using parallel single-mode with MTP® connections more than any other fibre type. Also, Facebook has undergone efforts to shorten their data centre cable links to 500 meters or less. Actions like these from companies with such major purchasing power have reduced the cost of single-mode optics to the point where the cost for 100 Gb/s single-mode optics dropped tenfold over the past two years, bringing it in line with multimode fibre.

As this trend continues, the market in general will find single-mode a more enticing option. For example, 100G-PSM4 single-mode technology, created in 2014 by a multi-source agreement group, is currently the same price as 100G-SR4 multimode transceivers. PSM4 transceivers were specifically designed as a low-cost option for 500 meters or less, using an 8-fibre MPO/MTP connection. Just as important, the price for long-reach single-mode solutions such as 100G-LR4 has dropped and will continue to drop over the next several years.

Smart Migration Requires Forward-Thinking Cabling Systems

Regardless of the type or size of the data centre, IT managers are looking for cabling systems that can weather multiple generations of tech upgrades with minimal disruption, dark fibres, or changes. Brand-Rex single-mode and multimode cabling systems not only meet current bandwidth requirements, but also provide the flexibility needed to meet future network demands, including 100G, 400G, and beyond.

These systems include high density patching, solutions for fast deployment, and customizable trunks and cable assemblies that give data centre managers the exact solution they need, delivered fast. To learn more about Brand-Rex fibre solutions, go to https://www.brand-rex.com/fibre.

Euroclass Cable Levels and Colour Coding

In Europe, Construction Products Regulation (CPR) introduced new EuroClass cabling levels as shown in the table below. The levels are designed to help save lives and protect buildings by enforcing a hierarchical system defining safety performance requirements in fires. Brand-Rex offers datacom cabling in copper and fibre in all applicable EuroClass levels, including Eca, Dca, Cca, and B2ca. This gives customers more options to meet the needs of their unique cabling environments and comply with CPR requirements specific to each different EU member state.

Note: As of 1st of July 2017, every applicable cable product must be CE marked, carry Euroclass level designation, and needs to be backed by a Declaration of Performance.

The final decision on required EuroClass performance levels lies with local authorities within each EU country. Always check local regulations to confirm what cable classification is required for a specific environment.

For easy recognition of EuroClass level, we are colour coding our copper cabling. Copper cable jackets are colored as shown below to clearly identify the level of EuroClass cable. This colour code approach is already being embraced by major European countries. 

The unique colour for each level simplifies visual inspections and allows for easy verification of CPR classification. Distributors can visually check the CPR classification of the cables in stock and are able to manage stock more easily because of this colour code approach. The colour code scheme also helps avoid the potential for mislabeling. Installers can quickly determine which cables go in the appropriate locations to comply with specification. Also, inspectors can easily confirm visually that the cable complies to national regulations.

Click here for more about CPR regulations and to see a list of CPR compliant cables.

News You Can Use


Vendors will ship 5 million 100 GbE Ethernet ports this year, and double that amount in 2018, according to Arista chairman Andreas Bechtolshiem. He is also forecasting 400 GbE shipments will reach 1 million units in 2019, and 4 million in 2020.

10GBASE-T data centre switch shipments increased more than 60% in 2016, according to Crehan Research Inc.

In June, market research firm Dell’Oro reported that at least five vendors are now shipping 2.5GBASE-T and 5GBASE-T switches, including Brocade, Cisco, Dell, H3C, and HPE. Dell’Oro expects more vendors to follow suit through the rest of the year, and they predict approximately four million 2.5/5.0 Gb/s switch ports will be shipped by the end of 2017.


Brand-Rex recently introduced a flat UHDX panel for customers who want ultra-high-density fibre patching with added accessibility and migration flexibility. The 1RU flat UHDX panel, part of the HDX platform, supports up to 144 LC fibres or 1,728 MTP fibres.


1965: Intel co-founder Gordon Moore publishes a theory in Electronics magazine that comes to be known as “Moore’s Law.” The projection stated that the transistor density on integrated circuits will double every year. It was adjusted to 18 months in 1975 and held closely to that rate until 2012.

Brand-Rex Wins Prestigious Scottish Engineering President’s Award

Brand-Rex, a Leviton company, was awarded the Scottish Engineering President’s Award for Outstanding Manufacturing Achievement 2017. The award recognises the company’s long history as a leading cable provider with a strong dedication to Scottish manufacturing. Brand-Rex has been designing and manufacturing advanced cable and connectivity solutions from its head office in Glenrothes since 1972.

The award also acknowledges Brand-Rex as a growing business, as it brings more engineering and manufacturing jobs to Scotland, invests in workforce training, and engages with the local community. Now as part of Leviton, Brand-Rex is one of only a few truly global structured cabling and connectivity companies, but with a manufacturing plant in Scotland, is recognised as a significant player in the Scottish Engineering community.

Left to right: Bryan Buchan, Chief Executive, Scottish Engineering; John Baxter,

Principal Speaker and ANRC Chairman; Ian Wilkie, Managing Director, Brand-Rex Ltd;

John Howie, President of Scottish Engineering.

Ian Wilkie, Managing Director of Brand-Rex, received the award at the Annual Awards Dinner, commenting: “I’m delighted to accept this award on behalf of all the staff at Brand-Rex. We are proud to be recognised for our contribution to Scottish engineering and manufacturing.”

To learn more about the Scottish Engineering Awards, go here.

Tech Tips

Fibre Cleaning: Wet to Dry

As many installers know, IPA stands for more than just a hoppy beer. When cleaning fibre end faces, isopropyl alcohol (IPA) is a good way to remove containments that dry wiping alone may not. However, failing to completely dry the end face can result in network issues. While IPA does evaporate, the evaporation is not quick enough or often incomplete before the connection is made.

If you use IPA, it must be 99% pure. Anything less than 99% can result in contamination of the fibre end face, having an adverse effect on the application. This will be particularly noticeable if an OTDR test is required. Additionally, IPA is anhydrous, but it will absorb moisture over time. It is critical that the solution be stored in an airtight container and exposure to air be minimized as much as possible.

While using IPA for cleaning is common, the use of a “solvent pen” is often found to be more effective. A dry lint free wipe is moistened with the solvent pen, then the connector placed gently on the moistened part of the lint free wipe and moved to a dry part of the lint free wipe.

Solvent pens are far more aggressive at removing contaminants than IPA. The solution also evaporates quicker and contains anti-static properties. That’s a useful feature, as dry wipes can put a static charge on the end face, attracting dust.