This document defines a Transport Subsystem, extending the Simple Network 

Management Protocol (SNMP) architecture defined in RFC 3411.  This document 

defines a subsystem to contain Transport Models, comparable to other subsystems 

in the RFC3411 architecture.  As work is being done to expand the transport to 

include secure transport such as SSH and TLS, using a subsystem will enable 

consistent design and modularity of such Transport Models.  This document 

identifies and describes some key aspects that need to be considered for any 

Transport Model for SNMP.