In computing, the Structure of Management Information (SMI), an adapted subset of ASN.1, operates in Simple Network Management Protocol (SNMP) to define sets ("modules") of related managed objects in a Management Information Base (MIB). SMI subdivides into three parts: module definitions, object definitions, and notification definitions. Module definitions are used when describing information modules. An ASN .1 macro, MODULE-IDENTITY, is used to concisely convey the semantics of an information module. Object definitions describe managed objects. An ASN.1 macro, OBJECT-TYPE, is used to concisely convey the syntax and semantics of a managed object. Notification definitions (aka "traps") are used when describing unsolicited transmissions of management information. An ASN.1 macro, NOTIFICATION-TYPE, concisely conveys the syntax and semantics of a notification. Implementations libsmi, a C library for accessing MIB information References External links , Standard 58, Conformance Statements for SMIv2 , Standard 58, Textual Conventions for SMIv2 , Standard 58, Structure of Management Information Version 2 (SMIv2) Network management Data modeling