Computer Network & Management
Assignment
Title: Structure of Management Information (SMI)
Structure of Management Information (SMI):
In the context of network management, for the Structure of Management Information
(SMI):
a) Name its three hierarchical layers.
The Structure of Management Information (SMI) standard is responsible for defining the
rules for how the Management Information Base (MIB) objects are structured, described
and organized. SMI is a data definition language allows dissimilar devices to communicate
by ensuring that they use a universal data representation for all management information.
SMI is needed to ensure the syntax and semantics of the network management data are
well defined and unambiguous.[TCP/IP Guide]
The three hierarchical layers of the Structure of Management Information are the base data
types, object-type and module-identity.
b) Explain the function of each layer.
The Base Data Type layer is use in the SYNTAX clause of the OBJECT-TYPE macro that
must be present. It defines the abstract data structure corresponding to the object. It
includes the following eleven basic data types: INTEGER, Integer32, Unsigned32,
OCTET STRING, OBJECT IDENTIFIER, IPaddress, Counter32, Counter64, Gauge32,
TimeTicks, and Opaque. Any restriction on size, range or enumerations specified in this
SYNTAX clause represents the maximal level of support which makes “protocol sense”.
[RFC2578]
The OBJECT-TYPE layer is use to specify the data type, status, and the semantics of
managed objects. It has basic of five mandatory characteristics namely, OBJECT-NAME,
SYNTAX, MAX ACCESS, STATUS, and DESCRIPTION, optionally with
OPTIONAL-CHARACTERISTICS. The OBJECT-NAME is obviously. The SYNTAX
clause specifies the basic data type of the object. The MAX-ACCESS clause specifies the
managed object either can be read-create, read-write, readtionly, accessible for notify only,
or not accessible. The STATUS clause specifies the object is current, obsolete or
deprecated. The DESCRIPTION clause contains a textual definition of the object.
[RFC2578][RFC2013]
The MODULE-IDENTITY layer is used to express concisely the semantics of an
information module. It groups related object into a Management Information Base (MIB)
module. Each MODULE-IDENTITY contains a number of clauses like the
LAST-UPDATED clause, ORGANIZATION clause, CONTACT-INFO clause,
DESCRIPTION clause and REVISION clause. Theses clauses document the date of last
updated, the organization and contact information of the author of the module, and a
textual description of the module, and the revision information such as the date of revision
and the revision description.[RFC2012][TCP-IP Guide]
c) For each layer, give four examples of defined entities.
Four examples of Base Data Types
1. Integer/Integer32 [RFC2578]
Integer/Integer32 is a 32-bit signed integer in two*ƒ*…½*ƒ‚¦s complement notation,
capable of holding a value between *ƒ*…½V2,147,483,648 and +2,147,483,647.
