Forwarding and Control Element Separation (ForCES) MIB
Extracted elements (23)
Association UP/DOWN notifications are not throttled at the MIB level because the CE itself is responsible for throttling the setup of associations; duplicating that throttling in the notification mechanism was deemed unnecessary.
Associations are removed from the MIB immediately when they leave the UP state rather than being retained in a historical table; the optional forcesAssociationEntryDownStats notification is provided to capture final statistics before the entry disappears.
forcesAssociationTimeUp serves a dual purpose: it records when the association entered the UP state and also allows uniquely identifying associations that share the same CE ID and FE ID index (distinguishing re-established associations from prior ones).
Statistics counters (ZeroBasedCounter32) reset to zero each time an association is re-established; counter discontinuities are tracked via forcesAssociationCounterDiscontinuityTime so management stations can detect and account for resets.
The MIB is intentionally read-only because the ForCES MIB is an observability tool, not a control plane; management of ForCES associations is performed through the ForCES protocol itself rather than through SNMP SET operations.
In NEs with multiple CEs, information about associations may be distributed among the CEs. Whether each CE independently implements its own MIB objects or CEs cooperate to present a unified view is explicitly out of scope for this document.
Deployment of SNMP versions prior to SNMPv3 is NOT RECOMMENDED; instead SNMPv3 with cryptographic security SHOULD be deployed.
Implementation of forcesNotificationStatsGroup (optional notifications with statistics) is RECOMMENDED per the MODULE-COMPLIANCE statement.
Implementation of forcesStatsGroup (optional statistics objects) is RECOMMENDED per the MODULE-COMPLIANCE statement, as these objects can be very useful in debugging connectivity problems.
Implementers are RECOMMENDED to consider the security features provided by the SNMPv3 framework, including full support for SNMPv3 cryptographic mechanisms for authentication and privacy.
The CE MUST also allow interaction with FEs supporting earlier ForCES protocol versions, even though forcesLatestProtocolVersionSupported reflects only the highest version the CE supports.
forcesAssociationEntry contains: CEID, FEID (index, not-accessible), running protocol version, time-up timestamp, time-down timestamp (accessible-for-notify only), HB sent/received counters, operational message sent/received counters, and a counter discontinuity timestamp.
forcesAssociationTable is a conceptual table indexed by forcesAssociationCEID and forcesAssociationFEID, containing one entry per active (UP state) CE-FE association with protocol version, timestamps, and message counters.
forcesAssociationTimeDown has MAX-ACCESS accessible-for-notify (not read-only) because the association is removed from the MIB immediately after it leaves the UP state; its value is only meaningful in down-notifications.
ForcesID is a textual convention defined as a 4-octet OCTET STRING used to identify both Control Elements and Forwarding Elements within the MIB.
forcesLatestProtocolVersionSupported is a read-only object indicating the highest ForCES protocol version supported by the CE; the CE must also allow interaction with FEs supporting earlier versions.
ForcesProtocolVersion is a textual convention defined as Integer32 (1..255) representing ForCES protocol version numbers; version 1 corresponds to RFC 5810.
Four SNMP notification types are defined: forcesAssociationEntryUp (mandatory), forcesAssociationEntryDown (mandatory), forcesAssociationEntryUpStats (optional, includes time-up), and forcesAssociationEntryDownStats (optional, includes all statistics).
The FORCES-MIB module is a read-only MIB that captures information about ForCES protocol associations (CE-FE pairs) in the UP state, including identifiers, configuration parameters, and statistics. It is assigned OID { mib-2 187 }.
IANA assigned the OBJECT IDENTIFIER { mib-2 187 } to the forcesMIB module, recorded in the SMI Numbers registry.
All managed objects in the ForCES MIB have MAX-ACCESS of read-only or accessible-for-notify; there are no read-write or read-create objects, so there is no risk of an intruder altering or creating MIB objects via SNMP SET operations.
Readable MIB objects (protocol versions and statistics) may be sensitive in some environments; access to GET and NOTIFY operations should be controlled and values should potentially be encrypted when transmitted via SNMP. SNMPv3 cryptographic mechanisms are the recommended mitigation.
An association enters the UP state when the CE sends an Association Setup Response with a successful result; it is added to the MIB at that point. The association leaves UP state (and is immediately removed from the MIB) if no message is received from the FE within a timeout period or an Association Teardown message is sent.