Simple Network Management Protocol（SNMP）is an Internet Standard protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device（71）.SNMP is a component of the Internet Protocol Suite as defined by the Internet（72）Task Force.SNMP operates in the（73）layer of the Internet protocol suite.All SNMP messages are transported via User（74）Protocol.An SNMP-managed network consists of three key components: a）Managed devices，b）（75）（i.e.，software which runs on managed devices），and c）Network management station（NMS）（i.e.，software which runs on the manager）.
