Example: State : := TEXTUAL CONVENTION STATUS current DESCRIPTION "Run Time States" SYNTAX INTEGER { Offline (0), Busy (1), Active (2) } 15.5 Conclusion Another important item to be discussed before we conclude is GDMO. The GDMO, a part of the SMI document, is a structured description language that pro- vides a way of specifying the class for objects, object behaviors, attributes, and class hierarchy. GDMO uses a set of templates for information modeling. Some of the templates include definitions for managed object, packages, attributes, and notifica- tions. Packages are used to group characteristics of a managed object and they can be included using a CHARACTERIZED BY or CONDITIONAL PACKAGES tag. Inheritance property is achieved using a DERIVED FROM tag and the object class is registered with an identifier using a REGISTERED AS tag. Refer X.722 document for more details about GDMO and tags like ALLOMORPHIC, PARAMETERS, and SO on that are not discussed here. A sample managed object class template is shown below: <class> MANAGED OBJECT CLASS [DERIVED FROM <class> [,<class>]*;] [ALLOMORPHIC SET <class> [,<class>]*; [CHARACTERIZED BY <package> [, <package>]*;] [CONDITIONAL PACKAGES <package> PRESENT IF <condition> [, <package> PRESENT IF <condition>]*; [PARAMETERS <parameter> [, <parameter>]*;] REGISTERED AS <object-identifier>; This chapter gives the reader an overview on ASN.1, BER, and SMI. These con- cepts form an important part of coding the network management information framework. Fundamentals of EMS, NMS and OSS/BSS Additional Reading 1. ISO/IEC/JTC 1/SC 6. ISO/IEC 8825-1:2002, Information technology: ASN.1 encod- ing rules. Washington, DC: ANSI, 2007. 2. John Larmouth and Morgan Kaufmann. ASN.1 Complete. San Francisco, CA: Morgan Kaufmann Publishers, 1999. 3. Olivier Dubuisson and Morgan Kaufmann. ASN.1 Communication between Heterogeneous Systems. San Diego, CA: Academic Press, 2000. 4. ISO/IEC/JTC 1/SC 6. ISO/IEC 10165-1:1993, Information Technology-Open Systems Interconnection-Management Information Servi