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The TCP/IP Guide  9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)       9  TCP/IP Network Configuration and Management Protocols (BOOTP, DHCP, SNMP and RMON)            9  TCP/IP Network Management Framework and Protocols (SNMP and RMON)                 9  TCP/IP Structure of Management Information (SMI) and Management Information Bases (MIBs)

TCP/IP Structure of Management Information (SMI) and Management Information Bases (MIBs) Overview 1 2 3 4 TCP/IP MIB Object Descriptors and Identifiers and the Object Name Hierarchy and Name Notation

SMIv2 Textual Conventions

In addition to these types, other defined types are also created to again, indicate more specific semantics for a particular data type. These are called textual conventions and are described in RFC 2579 for SMIv2. For example, a type called TimeStamp is defined which is the same as TimeTicks. However, seeing an object using the former rather than the latter makes it more clear that the variable is representing a particular time stamp value. Another is called TimeInterval, which is also just an integer underneath its name, but conveys a different interpreted meaning.

If all of the above seemed very confusing to you, note that this topic is in fact a significant simplification of SMI's object definitions. SNMP is so much fun! If an example will help, check out Table 207, which shows an object definition from RFC 3418, using SMIv2.

Note that DisplayString is a textual convention for a displayed text string. The last part, “{ system 6 }”, will be explained in the next topic.

TCP/IP Structure of Management Information (SMI) and Management Information Bases (MIBs) Overview 1 2 3 4 TCP/IP MIB Object Descriptors and Identifiers and the Object Name Hierarchy and Name Notation