Specifications

Mediatrix 4100 25
C HAPTER
2
MIB Structure and SNMP
This chapter describes how the Mediatrix 4100 uses the SNMP protocol for its configuration.
SNMP Overview
The Mediatrix 4100 uses the Simple Network Management Protocol (SNMP) for initial software configuration
provisioning and subsequent software configuration.
SNMP is a simple request-reply protocol for Internet network management services. It consists of network
management stations (in this document, they are referred to as a management server) communicating with
network elements. Management stations are normally workstations that display relevant facts about the
elements being monitored.
SNMP works over the IP (Internet Protocol) communication stack. SNMP network management consists of
three pieces:
 The protocol between the manager and the element (SNMP). This details the format of the
packets exchanged. Although a wide variety of transport protocols could be used, UDP is
normally used with SNMP.
 A set of common structures and an identification scheme used to reference the variables in the
MIB. This is called the Structure of Management Information (SMI).
 A Management Information Base (MIB) that specifies what variables the network elements
maintain (the information that can be queried and set by the manager).
Definitions
Structure of Management Information (SMI)
The SMI is the set of rules for specifying the management information that a device maintains. The
management information is actually a collection of managed objects, and these rules are used to both name
and define these managed objects.
Management Information Base (MIB)
A MIB is a structured collection of all the managed objects a device maintains. The managed objects are
structured in the form of a hierarchical tree. At the top of the tree is the most general information available
about a network. Each branch of the tree then gets more detailed into a specific network area, with the leaves
of the tree as specific as the MIB can get.
Object Identifier (OID)
Object Identifiers (OID) are strings of numbers. They are allocated in a hierarchical manner, so that, for
instance, the authority for “1.2.3” is the only one that can say what “1.2.3.4” means. The formal definition of
OIDs comes from ITU-T recommendation X.208 (ASN.1), which is available from the ITU.