The complexity of networks is steadily increasing. I remember the days when there were no clouds, only private data centers hosting applications that drove many digital services delivered over-the-top (OTT) of the internet. This rapidly evolved to deploying public cloud services offered by hyperscale cloud providers, creating hybrid and multi-cloud ecosystems.

Today, a new cloud ecosystem has emerged where hyperscale cloud providers have built out networks of large data centers and expanded global backbone networks to support regional markets, positioning data centers strategically in important hubs while rapidly expanding to the edge of the network. In parallel, regional cloud providers are rapidly building carrier-neutral and colocation data centers to meet increasing demand for a more direct and higher-performing interconnection infrastructure.

The increasing adoption of the cloud that drove this evolution and growth of data centers is also driving the need to increase the capacity, performance, and resiliency of the underlying network interconnection infrastructure and decrease its operational complexity and cost per bit. 

Equinix’s most recent Global Interconnection Index indicates global interconnection bandwidth is forecast to grow at a 40% five-year compound annual growth rate (CAGR), reaching 27,762 terabytes per second (Tbps), which equals 110 zettabytes of data exchanged yearly.

How can the interconnection infrastructure sustain this deluge of bandwidth demand while continuing to meet performance and resiliency expectations? How can this increasingly complex infrastructure be managed efficiently to deal with the increased complexity? This article will primarily focus on how optical data center interconnect (DCI) innovations can have a huge impact on addressing these requirements.

Leveraging the constant evolution in optical technology

If we believe in the proverb, “necessity is the mother of invention,” then the need to support the ever-growing capacity requirements will drive new innovations in optical technology to scale without limits — from its remote edges all the way to the core. 

Coherent optics offers an innovation in modulation techniques to provide improved optical performance to power the wavelengths in wavelength division multiplexing (WDM). Whether measured as bits per second (b/s), spectral efficiency (b/s/Hz), or capacity-reach (b/s-km), transmission speeds have seen massive scaling through the introduction and constant refinement of coherent optics technology. This resulted in exponential increases in wavelength speeds from 40 to 800Gb/s (gigabit per second). Additionally, it increased all-optical transmission reach from hundreds of kilometers to tens of thousands of kilometers. As we continue to innovate in this area, we will be able to enable further scaling and multi-Terabit coherent optics.

WDM technology transmits multiple data streams in parallel across several single wavelengths of light spread across the optical fiber transmission spectrum. Network operators are then enabled to largely scale their network bandwidth while paying off the high cost of deploying optical fiber over many channels and corresponding revenue streams. While WDM optical line systems a decade ago typically supported 40 to 80 wavelengths in the C-band spectrum, today, the majority of optical networks are able to operate over the C and L bands, doubling over the total fiber spectrum and its data-carrying capacity. Going forward, total network capacity is expected to continue to increase through future innovations in fiber and cable technology.

An evolved optical mesh architecture

Evolving existing 1+1 point-to-point data center interconnections (DCI) into an optical mesh topology is an investment that opens up a range of more cost-effective 1:N resiliency and survivability capabilities that are essential to mission-critical networks. A basic mesh topology is created by ensuring that each data center location is connected to at least two other locations.

The main benefit of an optical mesh network is resiliency. By planning an optical fiber mesh design, more resilient connectivity can be established through regional and international route diversity. When a primary data center link goes down, a secondary link can be used to transmit data to the destination through a different optical route.

The cloud requires huge amounts of data to be transported between data centers. It also requires data backup using synchronous and asynchronous replication between primary, secondary, and tertiary data centers and often between regions, both for on- and off-premises business continuity and disaster recovery. If a link goes down, data backup transfers can continue with limited disruption via alternate optical routes.

Optical automation

Although innovations in optical technology will increase speeds and reach, and architecture design aspects will increase resiliency and survivability, there is still the issue of scaling operations. Today’s competitive environment requires faster reactions to new demands to get maximum value from optical networks. But as networks become more complex, it’s getting much more difficult to reduce operating costs and increase agility. This is where automation can help.

Optical network automation leverages centralized policy-driven software to automate how optical networks behave. Automation helps to create a new kind of network that is more responsive, efficient, and reliable — while being simple to operate. With continuous innovation in network programming and mature, open-API interfaces, optical networks can be programmed to self-configure, optimize their performance in real time, and automatically recover from failure events. Some other benefits of automation are listed below.

  • Faster service deployment — Get services into your customers’ hands faster to grow revenue and create a differentiated customer experience.
  • Increased operational efficiency — Reduce the cost of repetitive tasks and make complex operations simple.
  • Greater agility — Rapidly deploy network updates and respond more quickly to changing demands.
  • Higher quality — Reduce human errors and system outages and deliver consistent, predictable outcomes.
The demands placed upon optical networks are daunting, but the continuous innovation in optical technology will continue to allow data center optical interconnect infrastructures to deliver the next generation of cloud services.