2008-12-19 2026-04-03 0-251 IETF Review 252-255 Experimental Use 0 Reserved 1 Open 2 Keepalive 3 Path Computation Request 4 Path Computation Reply 5 Notification 6 Error 7 Close 8 Path Computation Monitoring Request (PCMonReq) 9 Path Computation Monitoring Reply (PCMonRep) 10 Report 11 Update 12 LSP Initiate Request 13 StartTLS 14-251 Unassigned 252-255 Experimental Use 0-247 IETF Review 248-255 Experimental Use 0 Reserved 0-15 Reserved 1 OPEN 0 Reserved 1 OPEN 1 Open 1 OPEN 2-15 Unassigned 2 RP 0 Reserved 2 RP 1 Request Parameters 2 RP 2-15 Unassigned 3 NO-PATH 0 Reserved 3 NO-PATH 1 No Path 3 NO-PATH 2-15 Unassigned 4 END-POINTS 0 Reserved 4 END-POINTS 1 IPv4 addresses 4 END-POINTS 2 IPv6 addresses 4 END-POINTS 3 IPv4 4 END-POINTS 4 IPv6 4 END-POINTS 5 Generalized Endpoint RFC8779, Section 2.5 4 END-POINTS 6-15 Unassigned 5 BANDWIDTH 0 Reserved 5 BANDWIDTH 1 Requested bandwidth 5 BANDWIDTH 2 Bandwidth of an existing TE LSP for which a reoptimization is requested 5 BANDWIDTH 3 Generalized bandwidth RFC8779, Section 2.3 5 BANDWIDTH 4 Generalized bandwidth of an existing TE-LSP for which a reoptimization is requested RFC8779, Section 2.3 5 BANDWIDTH 5-15 Unassigned 6 METRIC 0 Reserved 6 METRIC 1 Metric 6 METRIC 2-15 Unassigned 7 ERO 0 Reserved 7 ERO 1 Explicit Route 7 ERO 2-15 Unassigned 8 RRO 0 Reserved 8 RRO 1 Recorded Route 8 RRO 2-15 Unassigned 9 LSPA 0 Reserved 9 LSPA 1 LSP Attributes 9 LSPA 2-15 Unassigned 10 IRO 0 Reserved 10 IRO 1 Include Route 10 IRO 2-15 Unassigned 11 SVEC 0 Reserved 11 SVEC 1 Synchronization Vector 11 SVEC 2-15 Unassigned 12 NOTIFICATION 0 Reserved 12 NOTIFICATION 1 Notification 12 NOTIFICATION 2-15 Unassigned 13 PCEP-ERROR 0 Reserved 13 PCEP-ERROR 1 PCEP Error 13 PCEP-ERROR 2-15 Unassigned 14 LOAD-BALANCING 0 Reserved 14 LOAD-BALANCING 1 Load Balancing 14 LOAD-BALANCING 2 Generalized Load Balancing RFC8779, Section 2.4 14 LOAD-BALANCING 3-15 Unassigned 15 CLOSE 0 Reserved 15 CLOSE 1 Close 15 CLOSE 2-15 Unassigned 16 PATH-KEY 0 Reserved 16 PATH-KEY 1 Path Key 16 PATH-KEY 2-15 Unassigned 17 XRO 0 Reserved 17 XRO 1 Route exclusion 17 XRO 2-15 Unassigned 18 Unassigned 0 Reserved 18 Unassigned 1-15 Unassigned 19 MONITORING 0 Reserved 19 MONITORING 1 Monitoring 19 MONITORING 2-15 Unassigned 20 PCC-REQ-ID 0 Reserved 20 PCC-REQ-ID 1 IPV4 Addresses 20 PCC-REQ-ID 2 IPV6 Addresses 20 PCC-REQ-ID 3-15 Unassigned 21 OF 0 Reserved 21 OF 1 Objective Function 21 OF 2-15 Unassigned 22 CLASSTYPE 0 Reserved 22 CLASSTYPE 1 Class-Type 22 CLASSTYPE 2-15 Unassigned 23 Unassigned 0 Reserved 23 Unassigned 1-15 Unassigned 24 GLOBAL-CONSTRAINTS 0 Reserved 24 GLOBAL-CONSTRAINTS 1 Global Constraints 24 GLOBAL-CONSTRAINTS 2-15 Unassigned 25 PCE-ID 0 Reserved 25 PCE-ID 1 IPV4 Addresses 25 PCE-ID 2 IPV6 Addresses 25 PCE-ID 3-15 Unassigned 26 PROC-TIME 0 Reserved 26 PROC-TIME 1 PROC-TIME 26 PROC-TIME 2-15 Unassigned 27 OVERLOAD 0 Reserved 27 OVERLOAD 1 overload 27 OVERLOAD 2-15 Unassigned 28 UNREACH-DESTINATION 0 Reserved 28 UNREACH-DESTINATION 1 IPv4 28 UNREACH-DESTINATION 2 IPv6 28 UNREACH-DESTINATION 3-15 Unassigned 29 SERO 0 Reserved 29 SERO 1 SERO 29 SERO 2-15 Unassigned 30 SRRO 0 Reserved 30 SRRO 1 SRRO 30 SRRO 2-15 Unassigned 31 BNC 0 Reserved 31 BNC 1 Branch node list 31 BNC 2 Non-branch node list 31 BNC 3-15 Unassigned 32 LSP 0 Reserved 32 LSP 1 LSP 32 LSP 2-15 Unassigned 33 SRP 0 Reserved 33 SRP 1 SRP 33 SRP 2-15 Unassigned 34 VENDOR-INFORMATION 0 Reserved 34 VENDOR-INFORMATION 1 Vendor-Specific Constraints 34 VENDOR-INFORMATION 2-15 Unassigned 35 BU 0 Reserved 35 BU 1 BU 35 BU 2-15 Unassigned 36 INTER-LAYER 0 Reserved 36 INTER-LAYER 1 Inter-layer 36 INTER-LAYER 2-15 Unassigned 37 SWITCH-LAYER 0 Reserved 37 SWITCH-LAYER 1 Switch-layer 37 SWITCH-LAYER 2-15 Unassigned 38 REQ-ADAP-CAP 0 Reserved 38 REQ-ADAP-CAP 1 Req-Adap-Cap 38 REQ-ADAP-CAP 2-15 Unassigned 39 SERVER-INDICATION 0 Reserved 39 SERVER-INDICATION 1 Server-indication 39 SERVER-INDICATION 2-15 Unassigned 40 ASSOCIATION 0 Reserved 40 ASSOCIATION 1 IPv4 40 ASSOCIATION 2 IPv6 40 ASSOCIATION 3-15 Unassigned 41 S2LS 0 Reserved 41 S2LS 1 S2LS 41 S2LS 2-15 Unassigned 42 WA 0 Reserved 42 WA 1 Wavelength Assignment 42 WA 2-15 Unassigned 43 FLOWSPEC 0 Reserved 43 FLOWSPEC 1 Flow Specification 43 FLOWSPEC 2-15 Unassigned 44 CCI Object-Type 0 Reserved 44 CCI Object-Type 1 MPLS Label 44 CCI Object-Type 2 Native IP 44 CCI Object-Type 3 SR P2MP Policy (TEMPORARY - registered 2024-08-27, extension registered 2025-07-10, expires 2026-08-27) 44 CCI Object-Type 4-15 Unassigned 45 PATH-ATTRIB (TEMPORARY - registered 2022-05-09, extension registered 2026-04-03, expires 2027-05-09) 0 Reserved 45 PATH-ATTRIB (TEMPORARY - registered 2022-05-09, extension registered 2026-04-03, expires 2027-05-09) 1 PATH-ATTRIB 45 PATH-ATTRIB 2-15 Unassigned 46 BGP Peer Info Object-Type 0 Reserved 46 BGP Peer Info Object-Type 1 IPv4 address 46 BGP Peer Info Object-Type 2 IPv6 address 46 BGP Peer Info Object-Type 3-15 Unassigned 47 Explicit Peer Route Object-Type 0 Reserved 47 Explicit Peer Route Object-Type 1 IPv4 address 47 Explicit Peer Route Object-Type 2 IPv6 address 47 Explicit Peer Route Object-Type 3-15 Unassigned 48 Peer Prefix Advertisement Object-Type 0 Reserved 48 Peer Prefix Advertisement Object-Type 1 IPv4 address 48 Peer Prefix Advertisement Object-Type 2 IPv6 address 48 Peer Prefix Advertisement Object-Type 3-15 Unassigned 49-247 Unassigned 0 Reserved 49-247 Unassigned 1-15 Unassigned 248-255 Experimental Use 0-15 Experimental Use IETF Review Bits are numbered from bit 0 as the most significant bit. 0-4 Unassigned IETF Review Bits are numbered from bit 0 as the most significant bit. 0-4 Unassigned IETF Review Bits are numbered from bit 0 as the most significant bit. 0-14 Unassigned 15-16 Routing Granularity (RG) RFC8779, Section 2.2 17 Core-tree computation (C-bit) 18 Fragmentation (F-bit) 19 P2MP (N-bit) 20 ERO-compression (E-bit) 21 Make-before-break (M-bit) 22 Report the request order (D-bit) 23 Path Key (P-bit) 24 Supply OF on response 25 VSPT 26 Strict/Loose 27 Bi-directional 28 Reoptimization 29-31 Priority IETF Review 0 No path satisfying the set of constraints could be found 1 PCE chain broken 2-255 Unassigned IETF Review Bits are numbered from bit 0 as the most significant bit. 0 Unsatisfied constrained indicated 1-15 Unassigned IETF Review 0 Reserved 1 IGP metric 2 TE metric 3 Hop Counts 4 Aggregate bandwidth consumption 5 Load of the most loaded link 6 Cumulative IGP cost 7 Cumulative TE cost 8 P2MP IGP metric 9 P2MP TE metric 10 P2MP hop count metric 11 Segment-ID (SID) Depth. 12 Path Delay metric 13 Path Delay Variation metric 14 Path Loss metric 15 P2MP Path Delay metric 16 P2MP Path Delay variation metric 17 P2MP Path Loss metric 18 Number of adaptations on a path 19 Number of layers on a path 20 Domain Count metric 21 Border Node Count metric 22 Path Min Delay metric 23 P2MP Path Min Delay metric 24 Path Bandwidth metric 25 P2MP Path Bandwidth metric 26-127 Unassigned 128-255 User-defined metric Bits are numbered from bit 0 as the most significant bit. IETF Review 0-5 Unassigned 6 Computed metric 7 Bound IETF Review Bits are numbered from bit 0 as the most significant bit. 0-5 Unassigned 6 Protection Enforcement 7 Local Protection Desired IETF Review 1 IPv4 prefix 2 IPv6 prefix 3 Unassigned 4 Unnumbered Interface ID 5 4-byte AS number 6 OSPF Area ID 7 IS-IS Area ID 8 Optical Interface Class List 9 Client Signal Information 10 Label 11-31 Unassigned 32 Autonomous system number 33 Explicit Exclusion Route subobject (EXRS) 34-127 Unassigned IETF Review Bits are numbered from bit 0 as the most significant bit. 0-17 Unassigned 18 Domain Diverse O-bit 19 Partial Path Diverse 20 Link Direction Diverse 21 SRLG Diverse 22 Node Diverse 23 Link Diverse IETF Review 0 Reserved 1-255 Reserved 1 Pending Request cancelled 1 PCC cancels a set of pending requests 1 Pending Request cancelled 2 PCE cancels a set of pending requests 1 Pending Request cancelled 3-255 Unassigned 2 PCE Congestion 1 PCE in congested state 2 PCE Congestion 2 PCE no longer in congested state 2 PCE Congestion 3-255 Unassigned 3 Unassigned 1-255 Unassigned 4 Stateful PCE resource limit exceeded 0 Unassigned 4 Stateful PCE resource limit exceeded 1 Entering resource limit exceeded state 4 Stateful PCE resource limit exceeded 2 Deprecated 4 Stateful PCE resource limit exceeded 3-255 Unassigned 5 Auto-Bandwidth Overwhelm State 0 Unassigned 5 Auto-Bandwidth Overwhelm State 1 Entering Auto-Bandwidth Overwhelm State 5 Auto-Bandwidth Overwhelm State 2 Clearing Auto-Bandwidth Overwhelm State 5 Auto-Bandwidth Overwhelm State 3-255 Unassigned 6-255 Unassigned 1-255 Unassigned IETF Review Bits are numbered from bit 0 as the most significant bit. 0-7 Unassigned 0-251 IETF Review The IETF Review procedure applies to all Error-values (0-255) for Error-Types in this range. 252-255 Experimental Use The Experimental Use policy applies to all Error-values (0-255) for Error-Types in this range. 0 Reserved 0-255 Reserved 1 PCEP session establishment failure 0 Unassigned 1 PCEP session establishment failure 1 reception of an invalid Open message or a non Open message. 1 PCEP session establishment failure 2 no Open message received before the expiration of the OpenWait timer 1 PCEP session establishment failure 3 unacceptable and non negotiable session characteristics 1 PCEP session establishment failure 4 unacceptable but negotiable session characteristics 1 PCEP session establishment failure 5 reception of a second Open message with still unacceptable session characteristics 1 PCEP session establishment failure 6 reception of a PCErr message proposing unacceptable session characteristics 1 PCEP session establishment failure 7 No Keepalive or PCErr message received before the expiration of the KeepWait timer 1 PCEP session establishment failure 8 PCEP version not supported 1 PCEP session establishment failure 9-255 Unassigned 2 Capability not supported 0-255 Unassigned 3 Unknown Object 0 Unassigned 3 Unknown Object 1 Unrecognized object class 3 Unknown Object 2 Unrecognized object Type 3 Unknown Object 3-255 Unassigned 4 Not supported object 0 Unassigned 4 Not supported object 1 Not supported object class 4 Not supported object 2 Not supported object Type 4 Not supported object 3 Unassigned 4 Not supported object 4 Unsupported parameter 4 Not supported object 5 Unsupported network performance constraint 4 Not supported object 6 BANDWIDTH object type 3 or 4 not supported 4 Not supported object 7 Unsupported endpoint type in END-POINTS Generalized Endpoint object type 4 Not supported object 8 Unsupported TLV present in END-POINTS Generalized Endpoint object type 4 Not supported object 9 Unsupported granularity in the RP object flags 4 Not supported object 10-255 Unassigned 5 Policy violation 0 Unassigned 5 Policy violation 1 C bit of the METRIC object set (request rejected) 5 Policy violation 2 O bit of the RP object cleared (request rejected) 5 Policy violation 3 objective function not allowed (request rejected) 5 Policy violation 4 OF bit of the RP object set (request rejected) 5 Policy violation 5 Global concurrent optimization not allowed 5 Policy violation 6 Monitoring message supported but rejected due to policy violation 5 Policy violation 7 P2MP Path computation is not allowed 5 Policy violation 8 Not allowed network performance constraint 5 Policy violation 9-255 Unassigned 6 Mandatory Object missing 0 Unassigned 6 Mandatory Object missing 1 RP object missing 6 Mandatory Object missing 2 RRO missing for a reoptimization request (R bit of the RP object set) 6 Mandatory Object missing 3 END-POINTS object missing 6 Mandatory Object missing 4 MONITORING object missing 6 Mandatory Object missing 5-7 Unassigned 6 Mandatory Object missing 8 LSP object missing 6 Mandatory Object missing 9 ERO object missing 6 Mandatory Object missing 10 SRP object missing 6 Mandatory Object missing 11 LSP-IDENTIFIERS TLV missing 6 Mandatory Object missing 12 LSP-DB-VERSION TLV missing 6 Mandatory Object missing 13 S2LS object missing 6 Mandatory Object missing 14 P2MP-LSP-IDENTIFIERS TLV missing 6 Mandatory Object missing 15 DISJOINTNESS-CONFIGURATION TLV missing 6 Mandatory Object missing 16 Scheduled TLV missing 6 Mandatory Object missing 17 CCI object missing 6 Mandatory Object missing 18 VIRTUAL-NETWORK-TLV missing 6 Mandatory Object missing 19 Native IP object missing 6 Mandatory Object missing 20 LABEL-REQUEST TLV missing 6 Mandatory Object missing 21 Missing SR Policy Mandatory TLV 6 Mandatory Object missing 22 Missing SR Policy Association 6 Mandatory Object missing 23-255 Unassigned 7 Synchronized path computation request missing 0-255 Unassigned 8 Unknown request reference 0-255 Unassigned 9 Attempt to establish a second PCEP session 0-255 Unassigned 10 Reception of an invalid object 0 Unassigned 10 Reception of an invalid object 1 Reception of an object with P flag not set although the P-flag must be set according to this specification. 10 Reception of an invalid object 2 Bad label value 10 Reception of an invalid object 3 Unsupported number of SR-ERO subobjects 10 Reception of an invalid object 4 Bad label format 10 Reception of an invalid object 5 ERO mixes SR-ERO subobjects with other subobject types 10 Reception of an invalid object 6 Both SID and NAI are absent in the SR-ERO subobject 10 Reception of an invalid object 7 Both SID and NAI are absent in the SR-RRO subobject 10 Reception of an invalid object 8 SYMBOLIC-PATH-NAME TLV missing 10 Reception of an invalid object 9 MSD exceeds the default for the PCEP session 10 Reception of an invalid object 10 RRO mixes SR-RRO subobjects with other subobject types 10 Reception of an invalid object 11 Malformed object 10 Reception of an invalid object 12 Missing PCE-SR-CAPABILITY sub-TLV 10 Reception of an invalid object 13 Unsupported NAI Type in the SR-ERO/SR-RRO subobject 10 Reception of an invalid objectD 14 Unknown SID 10 Reception of an invalid object 15 NAI cannot be resolved to a SID 10 Reception of an invalid object 16 Could not find SRGB 10 UReception of an invalid object 17 SID index exceeds SRGB size 10 Reception of an invalid object 18 Could not find SRLB 10 Reception of an invalid object 19 SID index exceeds SRLB size 10 Reception of an invalid object 20 Inconsistent SIDs in SR-ERO / SR-RRO subobjects 10 Reception of an invalid object 21 MSD must be nonzero 10 Reception of an invalid object 22 Mismatch of O field in S2LS and LSP object 10 Reception of an invalid object 23 Incompatible OF codes in H-PCE 10 Reception of an invalid object 24 Bad BANDWIDTH object type 3 or 4 10 Reception of an invalid object 25 Unsupported LSP Protection Flags in PROTECTION-ATTRIBUTE TLV 10 Reception of an invalid object 26 Unsupported Secondary LSP Protection Flags in PROTECTION-ATTRIBUTE TLV 10 Reception of an invalid object 27 Unsupported Link Protection Type in PROTECTION-ATTRIBUTE TLV 10 Reception of an invalid object 28 LABEL-SET TLV present with O bit set but without R bit set in RP 10 Reception of an invalid object 29 Wrong LABEL-SET TLV present with O and L bits set 10 Reception of an invalid object 30 Wrong LABEL-SET TLV present with O bit set and wrong format 10 Reception of an invalid object 31 Missing GMPLS-CAPABILITY TLV 10 Reception of an invalid object 32 Incompatible OF code 10 Reception of an invalid object 33 Missing PCECC Capability sub-TLV 10 Reception of an invalid object 34 Missing PCE-SRv6-CAPABILITY sub-TLV 10 Reception of an invalid object 35 Both SID and NAI are absent in SRv6-RRO subobject 10 Reception of an invalid object 36 RRO mixes SRv6-RRO subobjects with other subobject types 10 Reception of an invalid object 37 Invalid SRv6 SID Structure 10 Reception of an invalid object 38 Conflicting Path ID (TEMPORARY - registered 2022-05-09, extension registered 2026-04-03, expires 2027-05-09) 10 Reception of an invalid object 39 PCECC NATIVE-IP-TE-CAPABILITY bit is not set 10 Reception of an invalid object 40 Unsupported number of SRv6-ERO subobjects 10 Reception of an invalid object 41 Unsupported NAI Type in the SRv6-ERO/SRv6-RRO subobject 10 Reception of an invalid object 42 Both SID and NAI are absent in the SRv6-ERO subobject 10 Reception of an invalid object 43 ERO mixes SRv6-ERO subobjects with other subobject types 10 Reception of an invalid object 44 Missing SRPOLICY-CAPABILITY TLV 10 Reception of an invalid object 45-255 Unassigned 11 Unrecognized EXRS subobject 0-255 Unassigned 12 Diffserv-aware TE error 0 Unassigned 12 Diffserv-aware TE error 1 Unsupported class-type 12 Diffserv-aware TE error 2 Invalid class-type 12 Diffserv-aware TE error 3 Class-Type and setup priority do not form a configured TE-class 12 Diffserv-aware TE error 4-255 Unassigned 13 BRPC procedure completion failure 0 Unassigned 13 BRPC procedure completion failure 1 BRPC procedure not supported by one or more PCEs along the domain path 13 BRPC procedure completion failure 2-255 Unassigned 14 Unassigned 0-255 Unassigned 15 Global Concurrent Optimization Error 0 Unassigned 15 Global Concurrent Optimization Error 1 Insufficient memory 15 Global Concurrent Optimization Error 2 Global concurrent optimization not supported 15 Global Concurrent Optimization Error 3-255 Unassigned 16 P2MP Capability Error 0 Unassigned 16 P2MP Capability Error 1 The PCE cannot satisfy the request due to insufficient memory 16 P2MP Capability Error 2 The PCE is not capable of P2MP computation 16 P2MP Capability Error 3-255 Unassigned 17 P2MP END-POINTS Error 0 Unassigned 17 P2MP END-POINTS Error 1 The PCE cannot satisfy the request due to no END-POINTS with leaf type 2 17 P2MP END-POINTS Error 2 The PCE cannot satisfy the request due to no END-POINTS with leaf type 3 17 P2MP END-POINTS Error 3 The PCE cannot satisfy the request due to no END-POINTS with leaf type 4 17 P2MP END-POINTS Error 4 The PCE cannot satisfy the request due to inconsistent END-POINTS 17 P2MP END-POINTS Error 5-255 Unassigned 18 P2MP Fragmentation Error 0 Unassigned 18 P2MP Fragmentation Error 1 Fragmented request failure 18 P2MP Fragmentation Error 2 Fragmented Report failure 18 P2MP Fragmentation Error 3 Fragmented Update failure 18 P2MP Fragmentation Error 4 Fragmented Instantiation failure 18 P2MP Fragmentation Error 5-255 Unassigned 19 Invalid Operation 0 Unassigned 19 Invalid Operation 1 Attempted LSP Update Request for a non-delegated LSP. The PCEP-ERROR object is followed by the LSP object that identifies the LSP. 19 Invalid Operation 2 Attempted LSP Update Request if the stateful PCE capability was not advertised. 19 Invalid Operation 3 Attempted LSP Update Request for an LSP identified by an unknown PLSP-ID. 19 Invalid Operation 4 Unassigned 19 Invalid Operation 5 Attempted LSP State Report if active stateful PCE capability was not advertised. 19 Invalid Operation 6 PCE-initiated LSP limit reached 19 Invalid Operation 7 Delegation for PCE-initiated LSP cannot be revoked 19 Invalid Operation 8 Non-zero PLSP-ID in LSP Initiate Request 19 Invalid Operation 9 LSP is not PCE initiated 19 Invalid Operation 10 PCE-initiated operation-frequency limit reached 19 Invalid Operation 11 Attempted LSP State Report for P2MP if stateful PCE capability for P2MP was not advertised 19 Invalid Operation 12 Attempted LSP Update Request for P2MP if active stateful PCE capability for P2MP was not advertised 19 Invalid Operation 13 Attempted LSP Instantiation Request for P2MP if stateful PCE instantiation capability for P2MP was not advertised 19 Invalid Operation 14 Auto-Bandwidth capability was not advertised 19 Invalid Operation 15 Attempted LSP scheduling while the scheduling capability was not advertised 19 Invalid Operation 16 Attempted PCECC operations when PCECC capability was not advertised 19 Invalid Operation 17 Stateful PCE capability was not advertised 19 Invalid Operation 18 Unknown Label 19 Invalid Operation 19 Attempted SRv6 when the capability was not advertised 19 Invalid Operation 20 Not supported path backup (TEMPORARY - registered 2022-05-09, extension registered 2026-04-03, expires 2027-05-09) 19 Invalid Operation 21 Non-empty path (TEMPORARY - registered 2022-05-09, extension registered 2026-04-03, expires 2027-05-09) 19 Invalid Operation 22 Only one BPI, EPR, or PPA object can be included in this message 19 Invalid Operation 23 LSP state info unavailable for reoptimization 19 Invalid Operation 24 LSP state info for route exclusion not found 19 Invalid Operation 25 Attempted LSP update request for GMPLS if stateful PCE capability not advertised 19 Invalid Operation 26 Attempted LSP State Report for GMPLS if stateful PCE capability not advertised 19 Invalid Operation 27 Attempted LSP instantiation request for GMPLS if stateful PCE instantiation capability not advertised 19 Invalid Operation 28 Use of the Generalized Endpoint object type for non-GMPLS LSPs 19 Invalid Operation 29 Attempted Native IP operations when the capability was not advertised 19 Invalid Operation 30 Unknown Native IP Info 19 Invalid Operation 31 Invalid Color 19 Invalid Operation 32 Inconsistent Color 19 Invalid Operation 33 Attempted use of SR-Algorithm without advertised capability 19 Invalid Operation 34 Unsupported combination of constraints 19 Invalid Operation 35 Path modification is blocked by constraint 19 Invalid Operation 36-255 Unassigned 20 LSP State Synchronization Error 0 Unassigned 20 LSP State Synchronization Error 1 A PCE indicates to a PCC that it cannot process (an otherwise valid) LSP State Report. The PCEP- ERROR object is followed by the LSP object that identifies the LSP. 20 LSP State Synchronization Error 2 LSP-DB version mismatch. 20 LSP State Synchronization Error 3 Attempt to trigger synchronization before PCE trigger. 20 LSP State Synchronization Error 4 Attempt to trigger a synchronization when the PCE triggered synchronization capability has not been advertised. 20 LSP State Synchronization Error 5 A PCC indicates to a PCE that it cannot complete the State Synchronization. 20 LSP State Synchronization Error 6 Received an invalid LSP-DB Version Number. 20 LSP State Synchronization Error 7 Received an invalid Speaker Entity Identifier. 20 LSP State Synchronization Error 8-255 Unassigned 21 Invalid traffic engineering path setup type 0 Unassigned 21 Invalid traffic engineering path setup type 1 Unsupported path setup type 21 Invalid traffic engineering path setup type 2 Mismatched path setup type 21 Invalid traffic engineering path setup type 3-255 Unassigned 22 Unassigned 0-255 Unassigned 23 Bad parameter value 0 Unassigned 23 Bad parameter value 1 SYMBOLIC-PATH-NAME in use 23 Bad parameter value 2 Speaker identity included for an LSP that is not PCE initiated 23 Bad parameter value 3-255 Unassigned 24 LSP instantiation error 0 Unassigned 24 LSP instantiation error 1 Unacceptable instantiation parameters 24 LSP instantiation error 2 Internal error 24 LSP instantiation error 3 Signaling error 24 LSP instantiation error 4-255 Unassigned 25 PCEP StartTLS failure 0 Unassigned 25 PCEP StartTLS failure 1 Reception of StartTLS after any PCEP exchange 25 PCEP StartTLS failure 2 Reception of any other message apart from StartTLS, Open, or PCErr 25 PCEP StartTLS failure 3 Failure, connection without TLS is not possible 25 PCEP StartTLS failure 4 Failure, connection without TLS is possible 25 PCEP StartTLS failure 5 No StartTLS message (nor PCErr/Open) before StartTLSWait timer expiry 25 PCEP StartTLS failure 6-255 Unassigned 26 Association Error 0 Unassigned 26 Association Error 1 Association Type is not supported 26 Association Error 2 Too many LSPs in the association group 26 Association Error 3 Too many association groups 26 Association Error 4 Association unknown 26 Association Error 5 Operator-configured association information mismatch 26 Association Error 6 Association information mismatch 26 Association Error 7 Cannot join the association group 26 Association Error 8 Association ID not in range 26 Association Error 9 Tunnel ID or End points mismatch for Path Protection Association 26 Association Error 10 Attempt to add another working/protection LSP for Path Protection Association 26 Association Error 11 Protection type is not supported 26 Association Error 12 Not expecting policy parameters 26 Association Error 13 Unacceptable policy parameters 26 Association Error 14 Association group mismatch 26 Association Error 15 Tunnel mismatch in the association group 26 Association Error 16 Path Setup Type not supported 26 Association Error 17 Bidirectional LSP direction mismatch 26 Association Error 18 Bidirectional LSP co-routed mismatch 26 Association Error 19 Endpoint mismatch in the association group 26 Association Error 20 SR Policy Identifiers Mismatch 26 Association Error 21 SR Policy Candidate Path Identifier Mismatch 26 Association Error 22-255 Unassigned 27 WSON RWA error 0 Unassigned 27 WSON RWA error 1 Insufficient memory 27 WSON RWA error 2 RWA computation not supported 27 WSON RWA error 3 Syntactical encoding error 27 WSON RWA error 4-255 Unassigned 28 H-PCE Error 0 Unassigned 28 H-PCE Error 1 H-PCE Capability not advertised 28 H-PCE Error 2 Parent PCE Capability cannot be provided 28 H-PCE Error 3-255 Unassigned 29 Path computation failure 0 Unassigned 29 Path computation failure 1 Unacceptable request message 29 Path computation failure 2 Generalized bandwidth value not supported 29 Path computation failure 3 Label set constraint could not be met 29 Path computation failure 4 Label constraint could not be met 29 Path computation failure 5 Constraints could not be met for some intervals 29 Path computation failure 6-255 Unassigned 30 FlowSpec error 0 Unassigned 30 FlowSpec error 1 Unsupported FlowSpec 30 FlowSpec error 2 Malformed FlowSpec 30 FlowSpec error 3 Unresolvable Conflict 30 FlowSpec error 4 Unknown FlowSpec 30 FlowSpec error 5 Unsupported LPM Route 30 FlowSpec error 6-255 Unassigned 31 PCECC failure 0 Unassigned 31 PCECC failure 1 Label out of range 31 PCECC failure 2 Instruction failed 31 PCECC failure 3 Invalid CCI 31 PCECC failure 4 Unable to allocate the specified CCI 31 PCECC failure 5 Invalid next-hop information 31 FlowSpec error 6-255 Unassigned 32 Binding label/SID failure 0 Unassigned 32 Binding label/SID failure 1 Invalid SID 32 Binding label/SID failure 2 Unable to allocate the specified binding value 32 Binding label/SID failure 3 Unable to allocate a new binding label/SID 32 Binding label/SID failure 4 Unable to remove the binding value 32 Binding label/SID failure 5 Inconsistent binding types 32 Binding label/SID failure 6-255 Unassigned 33 Native IP TE failure 0 Unassigned 33 Native IP TE failure 1 Local IP is in use 33 Native IP TE failure 2 Remote IP is in use 33 Native IP TE failure 3 Explicit Peer Route Error 33 Native IP TE failure 4 EPR/BPI Peer Info mismatch 33 Native IP TE failure 5 BPI/PPA Address Family mismatch 33 Native IP TE failure 6 PPA/BPI Peer Info mismatch 33 Native IP TE failure 7-255 Unassigned 34-251 Unassigned 0-255 Unassigned 252-255 Reserved for Experimental Use 0-255 Reserved for Experimental Use IETF Review Bits are numbered from bit 0 as the most significant bit. 0-7 Unassigned IETF Review Bits are numbered from bit 0 as the most significant bit. 0-7 Unassigned IETF Review 0 Reserved 1 No explanation provided 2 DeadTimer expired 3 Reception of a malformed PCEP message 4 Reception of an unacceptable number of unknown requests/replies 5 Reception of an unacceptable number of unrecognized PCEP messages 6-255 Unassigned IETF Review Bits are numbered from bit 0 as the most significant bit. 0-7 Unassigned IETF Review 1-63 Unassigned 64 Path Key with 32-bit PCE ID 65 Path Key with 128-bit PCE ID 66-127 Unassigned IETF Review 1 IPv4 prefix 2 IPv6 prefix 3 Unassigned 4 Unnumbered Interface ID 5 4-byte AS number 6 OSPF Area ID 7 IS-IS Area ID 8 Optical Interface Class List 9 Client Signal Information 10 Label 11 LSP 12-31 Unassigned 32 Autonomous system number 33 Unassigned 34 SRLG 35-63 Unassigned 64 IPv4 Path Key 65 IPv6 Path Key 66-127 Unassigned IETF Review Bits are numbered from bit 0 as the most significant bit. 0-14 Unassigned 15 Fail (F-bit) 1-1023 IETF Review 1024-32767 First Come First Served 32768-65535 Reserved for Private Use 0 Reserved 1 MCP 2 MLP 3 MBP 4 MBC 5 MLL 6 MCC 7 SPT 8 MCT 9 Minimum Packet Loss Path (MPLP) 10 Maximum Under-Utilized Path (MUP) 11 Maximum Reserved Under-Utilized Path (MRUP) 12 Minimize the number of Transit Domains (MTD) 13 Minimize the number of Border Nodes (MBN) 14 Minimize the number of Common Transit Domains (MCTD) 15 Minimize the number of Shared Links (MSL) 16 Minimize the number of Shared SRLGs (MSS) 17 Minimize the number of Shared Nodes (MSN) 18-32767 Unassigned 32768-65535 Reserved for Private Use 0-65503 IETF Review 65504-65535 Experimental Use 0 Reserved 1 NO-PATH-VECTOR TLV 2 OVERLOADED-DURATION TLV 3 REQ-MISSING TLV 4 OF-List 5 Order TLV 6 P2MP capable 7 VENDOR-INFORMATION-TLV 8 Wavelength Selection 9 Wavelength Restriction 10 Wavelength Allocation 11 Optical Interface Class List 12 Client Signal Information 13 H-PCE-CAPABILITY 14 Domain-ID 15 H-PCE-FLAG 16 STATEFUL-PCE-CAPABILITY 17 SYMBOLIC-PATH-NAME 18 IPV4-LSP-IDENTIFIERS 19 IPV6-LSP-IDENTIFIERS 20 LSP-ERROR-CODE 21 RSVP-ERROR-SPEC 22 Unassigned 23 LSP-DB-VERSION 24 SPEAKER-ENTITY-ID 25 Unassigned 26 SR-PCE-CAPABILITY (deprecated) 27 Unassigned 28 PATH-SETUP-TYPE 29 Operator-configured Association Range 30 Global Association Source 31 Extended Association ID 32 P2MP-IPV4-LSP-IDENTIFIERS 33 P2MP-IPV6-LSP-IDENTIFIERS 34 PATH-SETUP-TYPE-CAPABILITY 35 ASSOC-Type-List 36 AUTO-BANDWIDTH-CAPABILITY 37 AUTO-BANDWIDTH-ATTRIBUTES 38 Path Protection Association Group TLV 39 IPV4-ADDRESS RFC8779, Section 2.5.2.1 40 IPV6-ADDRESS RFC8779, Section 2.5.2.2 41 UNNUMBERED-ENDPOINT RFC8779, Section 2.5.2.3 42 LABEL-REQUEST RFC8779, Section 2.5.2.4 43 LABEL-SET RFC8779, Section 2.5.2.5 44 PROTECTION-ATTRIBUTE RFC8779, Section 2.8 45 GMPLS-CAPABILITY RFC8779, Section 2.1.2 46 DISJOINTNESS-CONFIGURATION 47 DISJOINTNESS-STATUS 48 POLICY-PARAMETERS-TLV 49 SCHED-LSP-ATTRIBUTE 50 SCHED-PD-LSP-ATTRIBUTE 51 PCE-FLOWSPEC-CAPABILITY TLV 52 FLOW FILTER TLV 53 Unassigned 54 Bidirectional LSP Association Group TLV 55 TE-PATH-BINDING 56 SRPOLICY-POL-NAME 57 SRPOLICY-CPATH-ID 58 SRPOLICY-CPATH-NAME 59 SRPOLICY-CPATH-PREFERENCE 60 MULTIPATH-CAP (TEMPORARY - registered 2022-05-09, extension registered 2026-04-03, expires 2027-05-09) 61 MULTIPATH-WEIGHT (TEMPORARY - registered 2022-05-09, extension registered 2026-04-03, expires 2027-05-09) 62 MULTIPATH-BACKUP (TEMPORARY - registered 2022-05-09, extension registered 2026-04-03, expires 2027-05-09) 63 MULTIPATH-OPPDIR-PATH (TEMPORARY - registered 2022-05-09, extension registered 2026-04-03, expires 2027-05-09) 64 LSP-EXTENDED-FLAG 65 VIRTUAL-NETWORK-TLV 66 SR-Algorithm 67 Color 68 COMPUTATION-PRIORITY 69 EXPLICIT-NULL-LABEL-POLICY 70 INVALIDATION 71 SRPOLICY-CAPABILITY 72 PATH-MODIFICATION TLV 73 SR-P2MP-POLICY-CAPABILITY (TEMPORARY - registered 2024-08-27, extension registered 2025-07-10, expires 2026-08-27) 74 IPV4-SR-P2MP-INSTANCE-ID TLV (TEMPORARY - registered 2024-08-27, extension registered 2025-07-10, expires 2026-08-27) 75 IPV6-SR-P2MP-INSTANCE-ID TLV (TEMPORARY - registered 2024-08-27, extension registered 2025-07-10, expires 2026-08-27) 76-65503 Unassigned 65504-65535 Experimental Use IETF Review Bits are numbered from bit 0 as the most significant bit. 0-9 Unassigned 10 Requested disjoint computation not supported 11 Disjoint path not found 12 LOAD-BALANCING could not be performed with the bandwidth constraints 13 No label resource in range 14 No endpoint label resource in range 15 No endpoint label resource 16 Granularity not supported 17 No Resource 18 Protection Mismatch 19 Destination is not found in the indicated domain 20 No available resource in one or more domains 21 Unresponsive child PCE(s) 22 Destination domain unknown 23 No RWA constraints met 24 P2MP Reachability Problem 25 No GCO solution found 26 No GCO migration path found 27 PKS expansion failure 28 BRPC Path computation chain unavailable 29 Unknown Source 30 Unknown Destination 31 PCE currently Unavailable IETF Review Bits are numbered from bit 0 as the most significant bit. 0-18 Unassigned 19 Incomplete 20 Overload 21 Processing Time 22 General 23 Liveness IETF Review Bits are numbered from bit 0 as the most significant bit. 0-14 Unassigned 15 Estimated IETF Review Bits are numbered from bit 0 as the most significant bit. 0-7 Unassigned IETF Review 0 Reserved 1 LBU (Link Bandwidth Utilization) 2 LRBU (Link Residual Bandwidth Utilization) 3-255 Unassigned IETF Review 0-28 Unassigned 29 T Triggered Signaling Allowed 30 M Multi-Layer Requested 31 I Inter-Layer Allowed IETF Review Bits are numbered from bit 0 as the most significant bit. 0 PCE-allocation 1 ERO-compression 2 Fragmentation 3 P2MP 4 Create 5-7 Operational (3 bits) 8 Administrative 9 Remove 10 SYNC 11 Delegate IETF Review Bits are numbered from bit 0 as the most significant bit. 0-16 Unassigned 17 RELAX 18 STRICT-PATH-CAPABILITY 19 PATH-MODIFICATION-CAPABILITY 20 COLOR-CAPABILITY 21 PD-LSP-CAPABILITY (PD-bit) 22 LSP-SCHEDULING-CAPABILITY (B-bit) 23 P2MP-LSP-INSTANTIATION-CAPABILITY 24 P2MP-LSP-UPDATE-CAPABILITY 25 P2MP-CAPABILITY 26 TRIGGERED-INITIAL-SYNC 27 DELTA-LSP-SYNC-CAPABILITY 28 TRIGGERED-RESYNC 29 LSP-INSTANTIATION-CAPABILITY (I) 30 INCLUDE-DB-VERSION 31 LSP-UPDATE-CAPABILITY IETF Review 0 Reserved 1 Unknown reason 2 Limit reached for PCE-controlled LSPs 3 Too many pending LSP update requests 4 Unacceptable parameters 5 Internal error 6 LSP administratively brought down 7 LSP preempted 8 RSVP signaling error 9 Deprecated (Unsupported Color) 10 SID Verification fails 11-65535 Unassigned IETF Review 0-29 Unassigned 30 LSP Control Request 31 LSP-Remove IETF Review 0 Path is set up using the RSVP-TE signaling protocol 1 Traffic-engineering path is set up using Segment Routing. 2 Traffic engineering path is set up using PCECC mode 3 Traffic engineering path is set up using SRv6. 4 Native IP TE Path 5-255 Unassigned IETF Review 0 NAI is absent. 1 NAI is an IPv4 node ID. 2 NAI is an IPv6 node ID. 3 NAI is an IPv4 adjacency. 4 NAI is an IPv6 adjacency with global IPv6 addresses. 5 NAI is an unnumbered adjacency with IPv4 node IDs. 6 NAI is an IPv6 adjacency with link-local IPv6 addresses. 7-15 Unassigned IETF Review 0-6 Unassigned 7 SR-Algorithm Flag (A) 8 NAI is absent (F) 9 SID is absent (S) 10 SID specifies TC, S, and TTL in addition to an MPLS label (C) 11 SID specifies an MPLS label (M) IETF Review 0 Reserved 1 PCECC-CAPABILITY 2-25 Unassigned 26 SR-PCE-CAPABILITY 27 SRv6-PCE-CAPABILITY 28-65535 Unassigned IETF Review 0-4 Unassigned 5 SR-Algorithm Capability 6 Node or Adjacency Identifier (NAI) is supported (N) 7 Unlimited Maximum SID Depth (X) IETF Review 0-14 Unassigned 15 Wavelength Allocation Mode IETF Review 0 Inclusive List 1 Inclusive Range 2-255 Unassigned IETF Review 0-14 Unassigned 15 Wavelength Allocation Mode IETF Review 0-28 Unassigned 29-31 Operational (3 bits) IETF Review 0-30 Unassigned 31 P (Parent PCE Request bit) IETF Review 0 Reserved 1 2-byte AS number 2 4-byte AS number 3 4-byte OSPF area ID 4 Variable-length IS-IS area ID 5-255 Unassigned IETF Review 0-29 Unassigned 30 D (Disallow Domain Re-entry bit) 31 S (Domain Sequence bit) IETF Review 0-14 Unassigned 15 R (Removal) IETF Review 0 Reserved 1 Path Protection Association 2 Disjoint Association 3 Policy Association 4 Single-Sided Bidirectional LSP Association 5 Double-Sided Bidirectional LSP Association 6 SR Policy Association 7 VN Association 8 Bidirectional SR LSP Association 9 P2MP SR Policy Association (TEMPORARY - registered 2024-08-27, extension registered 2025-07-10, expires 2026-08-27) 10-65535 Unassigned IETF Review 0-31 Unassigned 0-65503 IETF Review 65504-65535 Experimental Use 0 Reserved 1 Sample-Interval 2 Adjustment-Interval 3 Down-Adjustment-Interval 4 Adjustment-Threshold 5 Adjustment-Threshold-Percentage 6 Down-Adjustment-Threshold 7 Down-Adjustment-Threshold-Percentage 8 Minimum-Bandwidth 9 Maximum-Bandwidth 10 Overflow-Threshold 11 Overflow-Threshold-Percentage 12 Underflow-Threshold 13 Underflow-Threshold-Percentage 14-65503 Unassigned 65504-65535 Experimental Use IETF Review 31 P - PROTECTION-LSP 30 S - SECONDARY-LSP 6-29 Unassigned 0-5 Protection Type Flags 0-244 IETF Review 245-255 Experimental Use 0 Point-to-Point 1 Point-to-Multipoint with leaf type 1 2 Point-to-Multipoint with leaf type 2 3 Point-to-Multipoint with leaf type 3 4 Point-to-Multipoint with leaf type 4 5 Point-to-Multipoint with leaf type 5 (TEMPORARY - registered 2024-08-27, extension registered 2025-07-10, expires 2026-08-27) 6-244 Unassigned 245-255 Experimental Use IETF Review 31 LSP-REPORT-CAPABILITY (R) 30 LSP-UPDATE-CAPABILITY (U) 29 LSP-INSTANTIATION-CAPABILITY (I) 0-28 Unassigned IETF Review 31 L - Link Diverse 30 N - Node Diverse 29 S - SRLG Diverse 28 P - Shortest Path 27 T - Strict Disjointness 0-26 Unassigned IETF Review 0 Reserved 1 REPEAT-EVERY-MONTH 2 REPEAT-EVERY-YEAR 3 REPEAT-EVERY-REPEAT-TIME-LENGTH 4-14 Unassigned 15 Reserved IETF Review 0-3 Unassigned 4 Relative Time (R-bit) 5 PCC Responsible (C-bit) 6 LSP Activated (A-bit) 7 Grace Period Included (G-bit) IETF Review 0-5 Unassigned 6 LPM (L bit) 7 Remove (R bit) 0-255 Reserved Must not be allocated. Usage mirrors the BGP Flowspec registry. 256-64506 Specification Required 64507-65531 First Come First Served 65532-65535 Experimental Use 0-255 Reserved. Must not be allocated. Usage mirrors the BGP FlowSpec registry and 256 Route Distinguisher 257 IPv4 Multicast 258 IPv6 Multicast 259-65531 Unassigned 65532-65535 Experimental Use IETF Review 0-29 Unassigned 30 C - Co-routed Path 31 R - Reverse LSP IETF Review 0-29 Unassigned 30 Native IP 31 Label IETF Review 0-13 Unassigned 14 C Bit - PCC allocation 15 O Bit - Specifies label is out-label IETF Review 0 MPLS Label 1 MPLS Label Stack Entry 2 SRv6 SID 3 SRv6 SID with Behavior and Structure 4-255 Unassigned IETF Review 0 R (Removal) 1 Deprecated (Specified-BSID-only) 2-7 Unassigned IETF Review 0 GMPLS LSP (G) 1 Bidirectional Co-routed LSP (B) 2-3 Routing Granularity (RG) 4 Strict-Path Flag (O) 5-31 Unassigned IETF Review 0-7 Unassigned IETF Review 0 NAI is absent. 1 Unassigned 2 NAI is an IPv6 node ID. 3 Unassigned 4 NAI is an IPv6 adjacency with global IPv6 addresses. 5 Unassigned 6 NAI is an IPv6 adjacency with link-local IPv6 addresses. 7-15 Unassigned IETF Review 0-6 Unassigned 7 SR-Algorithm Flag (A) 8 SID Verification (V) 9 SID Structure is present (T) 10 NAI is absent (F) 11 SID is absent (S) IETF Review 0-12 Unassigned 13 SR-Algorithm Capability 14 Node or Adjacency Identifier (NAI) is supported (N) 15 Unassigned IETF Review 0-15 Unassigned IETF Review 0 Reserved 1 BGP Session Established 2 BGP Session Establishment In Progress 3 BGP Session Down 4-255 Unassigned IETF Review 0 Reserved 1 ASes do not match - BGP Session Failure 2 Peer IP can't be reached - BGP Session Failure 3-255 Unassigned IETF Review 0-6 Unassigned 7 T (IP-in-IP) bit IETF Review 0-6 Unassigned 7 D: Dropping - the LSP is actively dropping traffic as a result of Drop-Upon-Invalid behavior being activated. IETF Review 0-6 Unassigned 7 D: Drop enabled - the Candidate Path has Drop-Upon-Invalid feature enabled. IETF Review 0-26 Unassigned 27 Stateless Operation (L-flag) 28 Unassigned 29 Invalidation (I-flag) 30 Explicit NULL Label Policy (E-flag) 31 Computation Priority (P-flag) IETF Review 0-13 Unassigned 14 Permanent (P) 15 Force (F)