This attribute is the SNMPv1 Community name. The value of this
attribute is used to authenticate SNMP messages received from
SNMPv1 management entities, and is placed in SNMP messages
sent out by the SNMPv1 network management entity. The string
'public' is commonly used.
When an SNMPv1 message is received, the community name in the
message is checked to ensure that it matches a Community string. If
there are no Manager subcomponents for that Community then the
level of access is determined by the accessMode attribute. If there
are Manager subcomponents for the Community then the
originating transport address in the message must match the
transportAddress of one of the Manager subcomponents, and the
level of access of the sending entity is determined by the privileges
attribute for that Manager.
The combination of communityString and tDomain attributes must
be unique across all Communies.