DMTF announces the public release of its Management Component Transport Protocol (MCTP) Host Interface Specification version 2.0.0 Work In Progress (WIP) (DSP0256), Management Component Transport Protocol (MCTP) Platform Communications Channel (PCC) Transport Binding Specification version 1.0.0 Work In Progress (WIP) (DSP0292) along with the previously released Memory-Mapped BMC Interface (MMBI) Specification version 1.0.0 (DSP0282), and Management Component Transport Protocol (MCTP) Memory-Mapped BMC Interface (MMBI) Transport Binding Specification (DSP0284).

These specifications are the latest generation of transport protocols developed by the Platform Management Communications Infrastructure (PMCI) Working Group.   

This MCTP Host Interface Specification 2.0 WIP describes how MCTP host interfaces are discovered (interfaces between a management controller and host software). This specification describes the host interface discovery and commands for registering software endpoints such as UEFI or system software. This is a new way of implementing a host interface using MCTP compatible with either PCC or MMBI Transport Bindings.

The MCTP PCC Transport Binding Specification 1.0 WIP defines a transport binding for facilitating communication between host software and on-chip embedded management controllers (i.e. Satellite Management Controller) via a PCC shared-memory interface. The MCTP Base Specification describes the protocol and commands used for communication within and initialization of an MCTP network. The MCTP over PCC transport binding definition in this specification includes a packet format, physical address format, message routing, and discovery mechanisms for MCTP over PCC communications.

Designed to be referenced by other standards organizations and developers, DMTF invites public comment on both WIPs before finalization. Feedback may be submitted on our website at https://www.dmtf.org/standards/feedback/.

The MMBI Specification version 1.0 was released in August of 2023 and defines the mechanisms facilitating communication between platform management components, typically host software and a BMC (baseboard management controller). Using the shared memory concept, this specification defines a protocol that allows packet exchanges between host software and BMC. The described memory mapping makes it possible for both boot code (such as UEFI firmware), as well as OS-level software (such as OS kernel or drivers) to establish efficient communication with BMC at bandwidth and latency limited by the underlying memory mapping mechanisms.

The MCTP over MMBI Transport Binding, released in August of 2023, defines how MCTP packets are delivered over a MMBI, which the new Host Interface specification can now leverage.

For more information about the PMCI Working Group and the platform management standards it defines, please visit https://www.dmtf.org/standards/pmci.