QSFP112 MSA Work Group Releases the Rev 1.0 Specification

The QSFP112 MSA group, formed to drive support for 112Gb/s per channel in 4x-channel QSFP systems and to support the QSFP 400G high-density interconnect ecosystem, recently announced that it has released its new Rev 1.0 specification. A total of 31 companies have come together to support the QSFP112 MSA to meet the industry’s need for high-speed, high-density networking solutions.

The QSFP112 MSA specification is designed to address the technical challenges of achieving higher speed signaling at 400G (4x112Gbps) and higher power consumption of modules, and to ensure interoperability and backward compatibility of modules and connectors/cages. QSFP112 connectors and cages will be backward compatible with legacy QSFP 40G (4x10G), 100G (4x25G), and 200G (4x56G-PAM4) modules. The QSFP112 module will also be able to be accepted by the QSFP-DD connector and cage.

The QSFP112 connector features a 0.6mm pitch SMT pin design solution that offers better SI performance and more design headroom for the entire link, winning the support of most members.

Systems designed with QSFP112 cages and connectors will be backward compatible with existing QSFP28 or QSFP56 transceiver, while systems designed for QSFP112 modules will be compatible with existing QSFP-DD800 cages and connectors.

The specification also takes full account of the cumulative tolerances between different interfaces and modules and can provide sufficient margin to ensure worst-case connection reliability.

The QSFP112 is targeted to provide thermal support for optical modules with up to 20 watts of power. The QSFP112 MSA has also been proven to meet IEEE802.3ck link 112Gbps PAM4 applications through real-world test results of the QSFP112 2M DAC. The QSFP112 MSA has also released hardware specifications for the QSFP112 2×1 connector and cage, optical module, and heat sink.

Founding members of the QSFP112 MSA include Accelink, Alibaba, Amphenol, Baidu, Credo, H3C, Hisense, Huaqin, II-VI, InnoLight, Inphi, Inspur, Kuaishou, Luxshare, Molex, Ruijie, TE, US Conec.

The following companies have also contributed to the MSA specification:  Applied Optoelectronics Inc, Broadex-Tech, Color-chip, Electric Connector Technology Co, Eoptolink, FIT, Insiga, Kingsignal, Mellanox, SiFotonics Technologies, Source Photonics, Yuanjie Semiconductor, Zhaolong.

The QSFP112 specification can be freely downloaded at the QSFP112 MSA http://www.qsfp112.com/QSFP112_MSA_Specification_Rev1.0.pdf.

Frequently Asked Questions

Q: Why do we need the QSFP112?

A: For datacenter internal networks, the evolution from 200G (QSFP56) optics to 400G (QSFP112) naturally allows for the reuse of existing fiber routes, avoiding the need to rebuild split fiber routes as they evolve directly to 800G.

The QSFP112 is the most convenient and cost-effective way to upgrade network bandwidth within the data center while keeping the network architecture physically and logically from 200G to 400G. QSFPs are easier to handle for higher speed signal integrity and thermal challenges. The adoption of 400G QSFP112 will leave the way open for possible future growth to 224G/lane speeds.

Q: What is the difference between QSFP112 and QSFP28/56?

A: The QSFP112 is focused on the next generation of connectors, cages, and modules for the QSFP family. It will focus on expanding bandwidth by scaling individual line speeds up to 112 Gb/s. Hardware changes are expected for signal integrity performance and EMI considerations for the specification.

Q: Is the QSFP112 backward compatible with the QSFP56 and QSFP28?

A: Yes. The anticipated changes to connectors and cages will not have any impact on the backward compatibility of receiving legacy QSFP56 and QSFP28 modules, including optical transceivers, active and passive copper cables (DAC).

Q: What are the key features of the QSFP112?

A: The QSFP112 will support the full suite of media and transceiver types popular in the networking industry. For media, this includes passive direct attach copper (DAC), multimode fiber (MMF), and single-mode fiber (SMF). For transceivers and active copper or active fiber assemblies, this includes Ethernet, Fibre Channel, and InfiniBand-defined 40 Gbps, 100 Gbps, 200 Gbps, and 400 Gbps transceivers and InfiniBand-defined transceiver and active fiber assemblies. In addition, backward compatibility with legacy QSFP form factors is critical to industry adoption.