SFP-DD MSA Releases Specification for High-Speed, High-Density Interface

The Small Form Factor Pluggable Double Density (SFP-DD) Multi Source Agreement (MSA) Group recently completed the initial hardware specification and drawings for the SFP-DD pluggable interface designed to enable high-speed, high-density networking equipment.  Targeting support up to 3.5 W optical modules in an enterprise environment, the SFP-DD form factor addresses the technical challenges of achieving a double-density interface and ensuring mechanical interoperability for module components produced by different manufacturers.

The SFP-DD electrical interface expands on the existing SFP pluggable form factor, a widely adopted interface used in data centers and other networking platforms.  The SFP single lane interface operates up to 28 Gbps NRZ or 56 Gbps PAM-4.  The new SFP-DD electrical interface is designed to support two lanes that operate up to 25 Gbps NRZ or 56 Gbps PAM-4 per lane, providing aggregate bandwidth of 50 Gbps or 112 Gbps.

By doubling the lane density and data speed, the SFP-DD interface will help address demand for increased port density and scalability in next-generation applications, with a primary focus on the server-side interconnect.  An SFP-DD server port along with QSFP-DD switch ports provides an overall doubling of the port density in network applications.

The SFP-DD hardware specification and drawings define key module, plug, and cage characteristics.  SFP-DD modules and direct-attach cable plugs use a common mechanical outline.  Modules and plugs provide a means to self-lock with the cage upon insertion.  Network equipment based on the SFP-DD will support legacy SFP modules and cables, and new double density products, for optimal design flexibility.

SFP-DD Key Features

  • A single port SMT connector and cage
  • Heat sink options for thermal management flexibility
  • Module mechanical definition
  • Support for optical and copper interfaces, with physical layer specifications to be determined outside the scope of the SFP-DD MSA

SFP-DD Key Benefits

  • Support for up to 3.5 W for optical modules
  • Enables two channels of high-speed electrical interfaces connecting to host
  • Backward compatibility to all current SFP style interfaces
  • Developed by industry consortium to enable multi-vendor interoperability

SFP-DD MSA founding members include Alibaba, Broadcom, Brocade, Cisco, Dell EMC, Finisar, Hewlett Packard Enterprise, Huawei, Intel, Juniper Networks, Lumentum, Mellanox Technologies, Molex, and TE Connectivity. For additional information about the SFP-DD form factor or to download the hardware specification and drawings, please visit the MSA website.