User-Based Security Model (USM) for Version 3 of the Simple Network Management Protocol (SNMPv3). U. Blumenthal, B. Wijnen. April 1999. http://www.faqs.org/rfcs/rfc2574.html
View-Based Access Control Model (VACM) for the Simple Network Management Protocol (SNMP). B. Wijnen, R. Presuhn, K. McCloghrie. April 1999. http://www.faqs.org/rfcs/rfc2575.html