The WebNMS Standalone SNMP Agent architecture supports all versions of SNMP and is designed in a manner to suit the requirements of Enterprise Vendors, Service Providers and the OEM markets. The following diagram gives an overview of the different components in SNMP agent and the interactions between them.
2.1 Transport Provider
SNMP messages are sent over various transport protocols. The protocols currently supported by WebNMS SNMP Agents are UDP/IP and TCP/IP. The communication between a manager and agent takes place through these transport providers.
2.2 Message Processing Unit
The Message Processing Unit is responsible for sending and extracting data from received messages. The Message Processing Unit potentially contains multiple Message Processing Models. Each Message Processing Model defines the format of a particular version of an SNMP message and co-ordinates the preparation and extraction of each such version-specific message format.
In this level, code is generated for a MIB given as input. The Request Handlers generated takes care of processing the request from the manager.
Thus, Message Processing Models receives the messages and processes them based on the version of the message.
The message processed can be instrumented to return specific values of the application. The generated code of the MIB Compiler has to be modified to get/set a MIB object value. Usually the MIB instrumentation differs based on the agent implementation. Database, runtime memory,xml, and text file storage support is available to store MIB objects value.