This Recommendation provides an information model for the management of subnetwork connection protection of Synchronous Digital Hierarchy (SDH) subnetwork. This model describes the managed object classes and their properties for the subnetwork connection protection function, as defined in ITU-T G.803 and as related to SDH network elements. These objects are useful to describe information exchanged across interfaces defined in M.3010 Telecommunications Management Network (TMN) architecture for the management of the subnetwork connection protection function.