What’s next for Ethernet?

Higher, more cost-efficient speeds and getting better integration between IT and operational technology (OT) environments are two of the hottest areas of Ethernet development.

That was on display this week at the Optical Fiber Communication conference where the Ethernet Alliance issued its latest Ethernet Roadmap, and a variety of vendors showed off the interoperability of the ubiquitous networking technology, now nearly 50 years old.

“Ethernet is the most important thing in the world that no one ever sees,” said Peter Jones, chair of the Ethernet Alliance and distinguished engineer with the Enterprise, Data Center & IoT Networks group at Cisco.

The Ethernet Alliance has been on a mission to make Ethernet developments get the attention of the industry and has, with the exception of 2021, released the roadmap of key trends and directions since 2015  to keep everyone up to date.

Ethernet speed is inevitably a hot topic.  Ethernet has evolved from 10Mb/sec to 400G and will go to 800G or possibly 1 terabyte Ethernet by about 2030, according to the roadmap. “The consumption of Ethernet bandwidth is not going to go down anytime soon,” Jones said. 

The focus for now is the development and use of 400G Ethernet. The Dell’Oro Group recently reported 400 Gigabit Ethernet shipments more than doubled, exceeding 2 million ports in 2021. And 400G deployments started to expand beyond just the hyperscalers, reaching smaller cloud service providers and large enterprises, according to Sameh Boujelbene, senior research director at Dell’Oro.

AI, machine learning are driving Ethernet speeds higher

“With voracious appetites for applications like AI and machine learning, hyperscale servers have moved to 25GbE, and are transitioning to 50GbE, 100GbE and beyond,” the Ethernet Roadmap says. “Unique networking architectures within these warehouse-scale data centers have driven a mix of copper cables, multi-mode fiber, and single-mode fiber solutions at 100, 200 and 400GbE. The bandwidth demands of both hyperscale data centers and service providers continue to grow exponentially, and they are adopting similar technologies.”

Last year, the alliance noted a number of developments that support increased Ethernet  speeds, including:

• IEEE 802.3cu, 100G and 400G operation over single-mode fiber at 100G per wavelength, has been published. The standard is designed to support cost-effective, more power-efficient single-mode fiber interfaces for 100G and 400G Ethernet using 100G optical technology to reduce cost and increase density.
• IEEE P802.3ck, 100G, 200G and 400G electrical interfaces based on 100G signaling, has progressed to the stage of working-group ballot. This standard, when completed, is intended to enable 100 Gbps electrical interfaces and support development of higher-density or lower-cost electrical interfaces for 100, 200 or 400G Ethernet.
• IEEE P802.3ct, 100G operation over DWDM (dense wavelength division multiplexing) systems, is complete and in final review before publication. The standard is significant as being the first Ethernet specification of coherent DWDM technology supporting 100G connectivity over lengths of at least 80 kilometers. IEEE P802.3cw, 400G Operation over DWDM systems, which is still in progress, extends the Ethernet specification for coherent DWDM technology to 400G.

As for the enterprise and campus networks the Ethernet Alliance says that over a billion Ethernet ports of all speeds are shipping per year. “Most of these ports are BASE-T at the access layer, with both multi-mode and single-mode fiber links (MMF/SMF) further into the network,” the roadmap says.

The changing needs of Wi-Fi access points and Enterprise-class client devices are driving technology transitions. BASE-T ports are making the transition from 1000BASE-T to 2.5G/5G/10G BASE-T, and optical ports are moving from 10G/40G to 25/100G, according to the roadmap.

One Ethernet for IT and OT

While higher speeds will influence the way Ethernet evolves, one area that needs development is integration of traditional IT Ethernet networks with industrial or operational Ethernet networks. Historically siloed IT and OT networks haven’t been very effectively integrated, but they need to be to take advantage of automation and management and other tools, Jones said.

“If we want Ethernet to succeed, we need to actually take Ethernet to the OT guys, not make them have to reevaluate their structures to be just like the IT guys are,” Jones said. The ultimate goal is a single-protocol network that addresses the needs of both IT and OT.

Some of that effort includes the development of the IEEE 802.3cg specification, published in February 2020, which defines the use of single-pair Ethernet (SPE) in many circumstances rather than a wide range of fieldbus cables, including RS‑485 twisted-pair, RG‑6 coaxial, and instrumentation cables. 

Automation, building, and industrial applications are gradually moving from old fieldbus style networks to Ethernet but right now, those older protocols that still are in the edge of the OT networks are a barrier to moving forward, Jones said.

Another component of the roadmap is service-provider influence on the future of Ethernet.

Service providers  have driven higher speed Ethernet for decades, the Roadmap shows. “Their multi-service aggregation needs continue to grow with support for router connections, EPON, optical transport network (OTN), and wired and wireless backhaul,” the roadmap says.  

In particular, 5G mobile deployment is driving dramatic increases in both fronthaul and backhaul applications, which continues to push Ethernet requirements for higher rates and longer distances. With a global consumption of video across devices, this shows no signs of changing, according to the alliance.

Multi-vendor, optical Ethernet interoperability

The Ethernet Alliance will also use this week’s OFC to show off multivendor interoperability across 50 to 800G technologies. The demo is expected to tie together Ethernet gear from 15 companies, including AMD, Arista, and Juniper.

“Demonstrating interoperability across a wide range of legacy systems and emerging technologies reinforces Ethernet’s inherent flexibility and shows why it has established itself as the foundation of networking globally.” said David Rodgers, Ethernet Alliance events chair and senior business development manager for telecommunications firm EXFO in a statement.