I've been reading RFC3414 about User-based Security Model (USM) for version 3 of the Simple Network Management Protocol (SNMPv3) , and it says :
There are at least two threats that an SNMP Security Model need not protect against. The security protocols defined in this memo do not provide protection against:
Denial of Service This SNMP Security Model does not attempt to address the broad range of attacks by which service on behalf of authorized users is denied. Indeed, such denial-of-service attacks are in many cases indistinguishable from the type of network failures with which any viable network management protocol must cope as a matter of course.
Traffic Analysis This SNMP Security Model does not attempt to address traffic analysis attacks. Indeed, many traffic patterns are predictable - devices may be managed on a regular basis by a relatively small number of management applications - and therefore there is no significant advantage afforded by protecting against traffic analysis.
I didn't quite understand how SNMP need not protect against them. Can someone explain this clearly please ? Thank you very much.