The SnmpUsmProxy object performs the same function as the SnmpProxy, except that it gets values from SNMP agents implementing the SNMPv3 protocol.
The SnmpUsmProxy object extends the SnmpUsmMibAgent abstract class, and as such can be registered in the SnmpV3AdaptorServer just like a local MIB generated by the mibgen tool. In a master agent application, one SnmpUsmProxy must be created per subagent. When creating the SnmpUsmProxy object, you must provide it with the following parameters to enable it to access the underlying subagent:
Subagent's IP address
Subagent's port number
Security parameters, namely context names, the user name and the security level, used for communicating with the subagent
Request context, namely the context engine ID and the context name
The SnmpUsmProxy receives requests in any version of SNMP, and always forwards them as SNMPv3 requests.