This document specifies the means by which the SPA features of networked component registration and message routing to endpoints on a SpaceWire network are facilitated. Accomplishing this requires low-level messaging on the SpaceWire network to provide the -convergence functions to allow the common SPA messages to be transported.

The role of a SPA subnet manager (SM-x) implemented for any transport protocol is to abstract the peculiarities of the subnetwork away, so that SPA core components and clients of those components need not know specific details to target components in the subnet for communication. To date, SPA common messaging has been bridged to several transport flavors, including USB, SpaceWire, and I2C. Research is in progress to develop the standard for optical transport as well.