The 400ZR standard: a new era in DCI open line systems

Is interoperable DCI technology the key to meeting soaring data demand? Here’s how the 400ZR format will shape the new breed of data center interconnect networks.
Arthur Cole
ADVA DCI OLS

Data centers are already tasked with maintaining broad connectivity with the cloud, individual users and other entities, and a key element of this network is the interconnect they use to communicate with each other. As the 5G era unfolds, traffic on this infrastructure will increase and become more dynamic in nature, which means today’s data center needs to ramp up its inter-networking capabilities at a rapid clip.

One of the main requirements for a modern data center interconnect (DCI) is an open line system (OLS). Current architectures are already straining from the increase in wide-band services like video conferencing and streaming, as well as the growing prevalence of cloud-based applications and big data. At the same time, the expanding diversity of modulation schemes and optical terminal designs make it difficult for any single architecture to provide the universal compatibility needed to meet current data demands.

Open interconnect

And open line system provides exactly the kind of interoperability needed to thrive in today’s environment. Not only does it offer the broadest interconnection with the lowest level of complexity, it delivers the longevity that allows network architectures to evolve with changing needs at low cost and without resorting to full hardware rip-and-replace.

One key element in open line systems is the 400ZR optimization standard. A key problem with optical platforms is the fact that, due to proprietary approaches to DSP, FEC and other tools, operators must deploy single-vendor solutions at both ends of the link. This reduces flexibility and stunts the pace of innovation. With 400ZR, providers are able to deploy multi-vendor devices at each end-point.

By implementing broad vendor interoperability, provides can quickly deploy advanced services and boost performance levels while taking advantage of broad economies of scale.
400ZR is currently taking shape under the Optical Internetworking Forum (OIF) as the OIF 400ZR project. The goal is to devise a set of standards governing single-span DCI infrastructure carrying 400GbE traffic up to 120km over G.652 fiber. The standard has already progressed to the point where SFFP modules are available that can plug directly into legacy routers and switches. By implementing broad vendor interoperability in this way, providers can quickly deploy advanced services and boost performance levels while taking advantage of broad economies of scale.

At the same time, the 400ZR wavelength is already supported by today’s DWDM amplifier and filtering platforms, enabling large-scale OLS DCI deployments capable of shuttling terabits of traffic over thousands of 400GbE interconnects. These architectures feature operational simplicity and easy implementation with minimal hardware and cabling. At the same time, remote monitoring enables high levels of uptime and availability.

400ZR and ADVA

ADVA’s latest contribution to the 400ZR format arrives in the latest iteration of the FSP 3000 DCI platform, which not only outperforms the standard itself but provides a full suite of open APIs to quickly integrate into virtually any legacy data center environment. The system has been optimized for 400Gbit/s DWDM links of up to 120km with either 75GHz or 100GHz channel spacing. It also features an OpenZR interface to expand the range of DCI applications it can support using third-party transceivers.

The FSP 3000 platform also features a host of diagnostic tools, such as built-in OTDR monitoring and optical channel monitoring to ensure high quality and maximum uptime.

For too long, the DCI has been viewed more as a cost center than a strategic advantage. Using open line systems, organizations will be better able to implement the kinds of innovative services that will differentiate them from the competition and contribute directly to revenue-generating business operations.

In short, the freedom to devise the DCI of your choice, not your vendor’s, will enable you to shape your overall data infrastructure to create a functionally unique environment that is ideally suited to your core business model.

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