E-lins H700 4g Router SNMP Function Overview

Simple Network Management Protocol is a widely used network monitoring and control protocol. Data are passed from SNMP agents, which are hardware and/or software processes reporting activity in each network device (hub, router, bridge, etc.) to the workstation console used to oversee the network. The agents return information contained in a MIB (Management Information Base), which is a data structure that defines what is obtainable from the device and what can be controlled (turned off, on, etc.). Originating in the Unix community, SNMP has become widely used on all major platforms.

SNMP 2 provides enhancements including security and an RMON (Remote Monitoring) MIB, which provides continuous feedback without having to be queried by the SNMP console. 

SNMP agents expose management data on the managed systems as variables. The protocol also permits active management tasks, such as configuration changes, through remote modification of these variables. The variables accessible via SNMP are organized in hierarchies. SNMP itself does not define which variables a managed system should offer. Rather, SNMP uses an extensible design which allows applications to define their own hierarchies. 

SNMP operates in the application layer of the Internet protocol suite. All SNMP messages are transported via User Data gram Protocol (UDP). The SNMP agent receives requests on UDP port 161. The manager may send requests from any available source port to port 161 in the agent. The agent response is sent back to the source port on the manager. The manager receives notifications (Traps and Inform Requests) on port 162. The agent may generate notifications from any available port.