Definitions of Textual Conventions for Pseudowire (PW) Management
Extracted elements (18)
The TCs are defined in a standalone module (PW-TC-STD-MIB) rather than inline in each PW MIB module so that PW-related MIB modules can import shared representations instead of each defining their own, improving consistency and reducing duplication across the PWE3 MIB suite.
The PwIndexType value for each PW MUST remain constant at least from one re-initialization to the next re-initialization, ensuring stable MIB table indexing across restarts.
When using PwIndexOrZeroType, the zero value is object-specific and MUST therefore be defined as part of the description of any object that uses this syntax, preventing ambiguous semantics.
PW-TC-STD-MIB is the top-level MIB module defining textual conventions for pseudowire edge-to-edge (PWE3) management, assigned OBJECT IDENTIFIER { mib-2 188 }. It imports from SNMPv2-SMI and SNMPv2-TC and is intended to be imported by PW-specific MIB modules rather than defining management objects itself.
PwAttachmentIdentifierType is an OCTET STRING (SIZE 0..255) used in the generalized FEC element to identify attachment forwarders and groups; a NULL identifier has zero length.
PwCfgIndexOrzero is an Unsigned32 (0..4294967295) index into technology-specific configuration tables; zero means no additional configuration information is applicable.
PwFragSize is an Unsigned32 indicating the desired fragmentation length in bytes for PSN-bound packets; a value of zero means fragmentation is not desired.
PwGenIdType is an Unsigned32 (0..254) representing the Attachment Group Identifier (AGI) Type and Attachment Individual Identifier (AII) Type used in generalized FEC signaling and configuration.
PwGroupID is a textual convention (Unsigned32) used as an administrative identifier for grouping a set of service-specific pseudowire services.
PwIDType is a textual convention (Unsigned32) representing the pseudowire identifier used together with other fields to identify the PW in a signaling session.
PwIndexOrZeroType extends PwIndexType by permitting the additional value zero. Zero is object-specific and must be defined per-object; typical uses include unknown pseudowire, no pseudowire, or all pseudowires.
PwIndexType is a textual convention (Unsigned32, range 1..4294967295) providing a unique index for each locally defined PW, used for indexing multiple MIB tables. Values are recommended to be assigned contiguously from 1.
PwStatus is a BITS type with five fault flags: pwNotForwarding(0), servicePwRxFault(1), servicePwTxFault(2), psnPwRxFault(3), psnPwTxFault(4). No bits set indicates no faults; bits indicate faults in specific directions or layers affecting the PW.
IANA assigned OBJECT IDENTIFIER { mib-2 188 } to the pwTcStdMIB module, recorded in the SMI Numbers registry.
The PW-TC-STD-MIB module defines only textual conventions and no management objects. Security considerations apply only to MIB modules that use these TCs to define management objects; this document itself has no impact on Internet security.
PwCwStatusTC represents the seven-state control word (CW) negotiation status: waitingForNextMsg(1), sentWrongBitErrorCode(2), rxWithdrawWithWrongBitErrorCode(3), illegalReceivedBit(4), cwPresent(5), cwNotPresent(6), notYetKnown(7). States reflect local C-bit configuration versus peer signaling outcomes per RFC 4447.
PwFragStatus is a BITS type with five flags reflecting fragmentation/reassembly negotiation state: noFrag(0), cfgFragGreaterThanPsnMtu(1), cfgFragButRemoteIncapable(2), remoteFragCapable(3), fragEnabled(4). fragEnabled requires local config, peer capability, and CW in use, per RFC 4623.
PwOperStatusTC defines six operational states for a pseudowire: up(1) — passing packets; down(2) — signaling incomplete or service-level fault; testing(3) — admin test mode; dormant(4) — pending external event; notPresent(5) — missing configuration or hardware; lowerLayerDown(6) — underlying PSN interface not up.