IEEE forms group to address 25 Gb/s Ethernet standard for cloud datacentres
The IEEE has formed a working group to explore the market opportunities and needs for a single-lane 25 Gb/s speed for server interconnects for Ethernet. The formation of the 25 Gb/s Ethernet Study Group comes shortly after Google, Arista, and Microsoft, operating as part of the recently formed 25G Ethernet Consortium released a specification enabling single-lane 25 Gb/s Ethernet and dual-lane 50 Gbps Ethernet links.
Echoing the 25G Ethernet Consortium, which is composed mainly of networking technology developers and cloud service providers, the IEEE said the reuse of serial lane 25 Gb/s signaling technology, developed to support 100 Gb/s Ethernet, optimises the cost of traffic per GB in datacentres built primarily for cloud – allowing these providers to send more data over the same links.
“The application of single-lane 25 Gb/s signaling technologies provides Ethernet with a solution set that can be reused by those companies building the datacentres of tomorrow. The new study group expects to lay the groundwork for a new Media Access Control (MAC) rate that will enable cost-optimised single-lane solutions that will increase network deployment efficiency,” said Mark Nowell, chair of the IEEE 802.3 25 Gb/s Ethernet Study Group and senior director, Cisco Systems.
“The heavy lifting in developing and standardising 25 Gb/s signaling technologies has been done as part of the development of 100 Gb/s Ethernet. These technologies can be reused to enable a single-lane 25 Gb/s Ethernet solution set for server interconnects for these future datacentres.”
Another IEEE standard (IEEE 802.3ba) already sets out 4 x 25 Gb/s signaling as a building block for 100 Gb/s Ethernet, but the current working group will expand the standard to cover physical layer specifications and management parameters for going over backplanes and copper twin-axial cables.
Currently the ‘IEEE P802.3bm 40 Gb/s and 100 Gb/s Fiber Optic Task Force’ is drafting a standard that will define 4 x 25 Gb/s operation for signal traces for chip-to-chip and chip-to-module applications, as well as for 25 Gb/s operation over four parallel multi-mode fibers.