4x400G MSA Formed to Facilitate 1.6T High-Density Optical Interconnects

A group of photonics industry leaders, including Arista, Broadcom, Intel, Molex, and AOI, has formed the 4×400G Multi-Source Agreement (MSA) as an industry consortium to facilitate the development and adoption of 1.6T high-density optical transceivers operating at 100Gbps per lane for data centers and cloud networking.

The MSA group members note that they will utilize the existing 100G Lambda optical interface standards, which can reach up to 10 km on single mode fiber, to meet end user requirements for next-generation network infrastructure. The high density 1.6T optical interfaces will interoperate with standard 400G FR4 and 2×400G FR4 modules. The group indicates that this work could lead to 4x400G LR4 optical modules fully interoperable with 400G LR4 and 2x400G LR4 modules.

The Booster for Optical Communications

The 4×400G MSA will promote a common set of high volume optical 400G interface specifications which will enable a healthy ecosystem of partners and accelerate time to market of 1.6T optical interconnects. The 4x400G MSA will specify 1.6T interfaces that are backward compatible with 800G and 400G standards currently in use. The well-established optical interface specifications and backward compatibility are critically important to the development of the industry.

Get Ready for Next Generation Ethernet

The 4×400G Multi-source Agreement will help end users to handle next-generation Ethernet network infrastructure needs based on 51.2T switch ASICs, by facilitating fully interoperable optical links using existing and validated IEEE standard 802.3cu optical interfaces with end-to-end KP4 FEC for reaches up to 100m on multimode fiber or up to 2km on single mode fiber, and interfaces based on the popular 100G Lambda MSA for reaches up to 10km.

The Challenge of Competing with 200G Optics

The MSA notes that a 1.6T 4×400G solution can be delivered expeditiously, and the members anticipate optical modules based on their upcoming specifications could be initially deployed as early as 2023. However, the industry is also developing 200G per lane optics solutions. Marvell plans to launch 200G per lane DSPs in 2023 and it may take another year to qualify these new chips. Once the qualification process is complete and transceivers based on them are available, 4×400G transceivers will face an enormous market dilemma.

Whether 200G per lane optics solutions will be as reliable as 100G per lane solutions and how long it will take to quality new chips are unknown. However, the 4×400G MSA still requires efforts to mitigate the risks associated with the performance of 200G optics, while launching 16×100G transceivers as soon as possible.