18 September 2018

QSFP-DD MSA Group releases updated 4.0 Hardware Specification and Common Management Interface Specification

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The Quad Small Form Factor Pluggable Double Density (QSFP-DD) Multi Source Agreement (MSA) group (supported by 66 companies to address the need for an improved high-density, high-speed networking solution) has released an updated 4.0 Hardware Specification for the QSFP-DD form factor. Notable features include additions to the thermal section, synchronous clocking and improved keying.

In addition to the updated 4.0 specification that addresses broad market support and overcomes the technical challenges of specifying a QSFP28-compatible double-density interface, the group has also released the 3.0 Common Management Interface Specification (CMIS), which provides a set of management interactions and a register map for 8- and 16-lane modules.

The initial work on the CMIS was done by the QSFP-DD MSA and was later expanded to include other industry standards groups. The CMIS is similar to the QSFP module management interface specification with expansion to the management of 8 and 16 lanes using a ‘banking’ feature. The CMIS is the first management specification designed with the intent to cover a wide range of module form factors, functionalities and applications, ranging from passive copper cable assemblies to coherent DWDM modules.

The CMIS defines the host-to-module interactions needed to ensure that modules will initialize and operate consistently through the management interface. The defined state machines simplify operation by allowing the host to identify and control the power-up sequencing of new high-power class modules.

“Through strategic collaborations we are able to provide specifications that address the challenges of common management requirements for the mechanical, thermal and electrical parameters,” says Tom Palkert, editor of the QSFP-DD MSA specifications. “The CMIS breaks the barriers to multi-vendor interoperability by addressing the ability of next-generation modules to meet user needs.”

The MSA QSFP-DD HW Specification supports up to 400Gbps in aggregate over an 8 x 50Gbps electrical interface. The CMIS supports multiple interface settings and speed negotiation controls and allows support for multiple ‘Data Paths’ where each ‘Data Path’ consists of a sub-group of lanes to be controlled together within the multi-lane module.

Established in March 2016, the QSFP-DD MSA group accepted the challenge to meet the market demand for a next-generation high-density, high-speed pluggable backwards-compatible module form factor. QSFP-DD MSA founder-promoters include Broadcom, Cisco, Corning, Finisar, Foxconn Interconnect Technology, Huawei, Intel, Juniper Networks, Lumentum, Luxtera, Mellanox Technologies, Molex, Oclaro and TE Connectivity.

Contributors include Acacia, ACON, Alibaba, Amphenol, Applied Optoelectronics, APRESIA Systems, Cavium, Celestica, Ciena, ColorChip, Credo, Dell EMC, Delta Products, Dust Photonics, Eoptolink, Fourte, Fujitsu Optical Components, Genesis, H3C, Hisense Broadband, Hitachi Metals, Hewlett Packard Enterprise, InnoLight, Innovium, Inphi, Ixia, JPC, Kaiam, LEONI, Lorom, Luxshare-ICT, MACOM, MaxLinear, MultiLane, NeoPhotonics, Nokia, Panduit, PHY-SI, Ranovus, Samtec, SENKO, Semtech, Sicoya, Siemon, Skorpios Technologies, Source Photonics, Spectra7 Microsystems, Spirent, Sumitomo Electric, US Conec, Xilinx, and Yamaichi Electronics.

It is expected that many MSA members will be demonstrating QSFP-DD products at the European Conference on Optical Communication (ECOC 2018) in Rome, Italy (23-27 September).

See related items:

QSFP-DD MSA releases QSFP-DD thermal white paper

QSFP-DD MSA Group releases 3.0 Hardware specification

Tags: QSFP Optical transceivers 400G

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Visit: www.qsfp-dd.com