DMTF Releases Update to PLDM for Redfish Device Enablement Specification

Posted on Thu, 01/24/2019 - 00:00

DMTF has released a new version of its Platform Level Data Model (PLDM) for Redfish® Device Enablement Specification (RDE) as a Work In Progress. This standard enables a management controller to present Redfish-conformant management of I/O adapters in a server, without the need for code specific to each adapter family/vendor/model. Version 0.9.0a of the RDE standard, as well as a new “deep-dive” presentation, are now available for download. 

RDE describes the operation and format of request messages (also referred to as commands) and response messages, designed to be delivered using Platform Level Data Model (PLDM) messaging. Bringing Redfish management to devices, which have a small memory footprint and limited processing capabilities, the specification defines the use of Binary Encoded JSON (BEJ) to help compress message size significantly.

How RDE Works

Using Redfish, messages are generated by a Redfish client through interactions with a user or a script, and communicated via JSON over HTTP or HTTPS to a management controller. 

Using RDE, the management controller will encode the message into a binary format (BEJ) and communicate it using PLDM as the transport to an appropriate device for servicing. The device processes the message and returns the response back using PLDM to the management controller, again in binary format.  The management controller then decodes the response and constructs a standard Redfish response in JSON over HTTP or HTTPS for delivery back to the client. The full technical details, including architecture, discovery and registration, operations, and more advanced topics are detailed in the new RDE deep-dive presentation

RDE is developed by DMTF’s Platform Management Components Intercommunications (PMCI) Working Group, which defines standards to address “inside the box” communication and functional interfaces. It can be used in conjunction with other PMCI standards, such as the PLDM Firmware Update Specification, to provide a comprehensive, common architecture for improved communication between management subsystem components. RDE version 0.9.0a is the latest example of the ongoing hard work and close collaboration between DMTF Working Groups (including PMCI, SMBIOS and Redfish Forum) to seamlessly address both internal- and external-facing interfaces and protocols for system management.

To learn more about PMCI WG and to download the latest documents, click here.