To meet a need for faster high-end Ethernet, 800GbE has become a formal specification, but the reality on the ground is that 400GbE shipments are just ramping up, and much lower speeds are what’s in common use.
Just as the stage is set for 400G Ethernet (GbE) to roll out in force later this year, mainly in hyperscaler, telco and large data-center networks, there is a call to boost that speed to 800GbE or even higher in the coming years.
The need for increased speed in data centers and cloud services speeds is driven by many things including the continued growth of hyperscale networks from players like Google, Amazon and Facebook, but also the more distributed and mobile workloads modern networks support.
This month, the Ethernet Technology Consortium, previously known as the 25 Gigabit Ethernet Consortium, announced completion of a specification for 800GbE this year. The ETC has more than 45 members, among them Arista, Broadcom, Cisco, Dell, Google, Mellanox and Microsoft.
According to the group, the 800 GbE specification introduces a new media access control (MAC) and Physical Coding Sublayer (PCS). “It essentially re-purposes two sets of the existing 400GbE logic from the IEEE 802.3bs standard with a few modifications in order to distribute the data across eight 106 Gb/s physical lanes. As the PCS is reused, the standard RS(544, 514) forward error correction is retained, for simple compatibility with existing physical layer specifications,” the group stated. A lane can be a copper twisted pair or in optical cables a strand of fiber or a wavelength.
“The intent with this work was to repurpose the standard 400GbE logic as much as possible to create an 800 GbE MAC and PCS specification with minimal overhead cost to users implementing multi-rate Ethernet ports,” said Rob Stone, technical working group chair of the Ethernet Technology Consortium in a post.
Another larger advocacy group, the Ethernet Alliance, which includes many of the same members as the ETC, will begin exploring 800GbE as well. The Alliance will later this year host a one-day Technology Exploration Forum to focus on the trade-offs, use-cases and technology challenges surrounding the selection of what should be the next Ethernet rate.
“The Forum will bring together key experts from both the end user community as well as equipment and component manufacturers to discuss and debate these key issues with the goal of understanding end-user requirements and building consensus on what Ethernet’s next rate should be,” the group stated in a post.