RFC 1448 (rfc1448) - Page 3 of 35

Protocol Operations for version 2 of the Simple Network Management Protocol (SNMPv2)

          RFC 1448        Protocol Operations for SNMPv2      April 1993


          2.  Overview

          2.1.  Roles of Protocol Entities

          A SNMPv2 entity may operate in a manager role or an agent
          role.

          A SNMPv2 entity acts in an agent role when it performs SNMPv2
          management operations in response to received SNMPv2 protocol
          messages (other than an inform notification) or when it sends
          trap notifications.

          A SNMPv2 entity acts in a manager role when it initiates
          SNMPv2 management operations by the generation of SNMPv2
          protocol messages or when it performs SNMPv2 management
          operations in response to received trap or inform
          notifications.

          A SNMPv2 entity may support either or both roles, as dictated
          by its implementation and configuration.  Further, a SNMPv2
          entity can also act in the role of a proxy agent, in which it
          appears to be acting in an agent role, but satisfies
          management requests by acting in a manager role with a remote
          entity.  The use of proxy agents and the transparency
          principle that defines their behavior is described in [3].


          2.2.  Management Information

          The term, variable, refers to an instance of a non-aggregate
          object type defined according to the conventions set forth in
          the SMI [2] or the textual conventions based on the SMI [4].
          The term, variable binding, normally refers to the pairing of
          the name of a variable and its associated value.  However, if
          certain kinds of exceptional conditions occur during
          processing of a retrieval request, a variable binding will
          pair a name and an indication of that exception.

          A variable-binding list is a simple list of variable bindings.

          The name of a variable is an OBJECT IDENTIFIER which is the
          concatenation of the OBJECT IDENTIFIER of the corresponding
          object-type together with an OBJECT IDENTIFIER fragment
          identifying the instance.  The OBJECT IDENTIFIER of the
          corresponding object-type is called the OBJECT IDENTIFIER





          Case, McCloghrie, Rose & Waldbusser