Network Shaofu. Peng Internet-Draft ZTE Corporation Intended status: Standards Track 8 January 2026 Expires: 12 July 2026 Advertising DetNet Resources in BGP Link-State draft-peng-idr-bgp-ls-detnet-te-00 Abstract BGP Link-State (BGP-LS) enables the collection of various topology information from the network. This document specifies the advertisement of DetNet scheduling resources in BGP-LS, providing a foundation for the controller to calculate DetNet based traffic engineering path. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 12 July 2026. Copyright Notice Copyright (c) 2026 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Peng Expires 12 July 2026 [Page 1] Internet-Draft BGP-LS Adv DetNet Resources January 2026 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 2. Advertising DetNet Scheduling Capability . . . . . . . . . . 3 3. Advertising DetNet Maximum Reservable Bandwidth . . . . . . . 5 4. Advertising DetNet Unreserved Bandwidth . . . . . . . . . . . 7 5. Advertising DetNet Maximum Reservable Burst . . . . . . . . . 8 6. Advertising DetNet Unreserved Burst . . . . . . . . . . . . . 10 7. Advertising DetNet Timeslot Mapping . . . . . . . . . . . . . 11 8. Advertising DetNet Period Mapping . . . . . . . . . . . . . . 12 9. Advertising DetNet Intra-node Forwarding Delay . . . . . . . 13 10. Operations . . . . . . . . . . . . . . . . . . . . . . . . . 14 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 12. Security Considerations . . . . . . . . . . . . . . . . . . . 14 13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 15 14.1. Normative References . . . . . . . . . . . . . . . . . . 15 14.2. Informative References . . . . . . . . . . . . . . . . . 16 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 17 1. Introduction [RFC8655] describes the architecture of a deterministic networking (DetNet) and defines the QoS goals of deterministic forwarding: 1) Minimum and maximum end-to-end latency from source to destination, timely delivery, and bounded jitter (packet delay variation); 2) A bounded packet loss ratio under various assumptions about the operational states of the nodes and links; 3) An upper bound on out- of-order packet delivery. In order to achieve these goals, DetNet use resource reservation, explicit routing, and service protection, as well as other means. A deterministic forwarding path is typically (but not necessarily) an explicit route so that it does not suffer temporary interruptions caused by the convergence of routing or bridging protocols. Some enhanced data plane (EDP) queueing mechanisms are under discussion in DetNet WG to meet large scaling requirements in IP/MPLS network. According to [Net-Calculus], queueing mechanisms may be roughly classified into two categories: rate based, and delay based. The latency bound provided by rate based mechanisms is generally overestimated due to inversely proportional to the service rate of the flow or flow aggregate. While the latency bound provided by delay based mechanisms is more tighter due to accurately planning the scheduling slot or deadline. Note that even if two mechanisms belong to the same category, e.g., both based on traffic class queuing, they may provide different worst case latency due to different underlying scheduling principles. Peng Expires 12 July 2026 [Page 2] Internet-Draft BGP-LS Adv DetNet Resources January 2026 [I-D.peng-lsr-deterministic-traffic-engineering] provides the abstraction and quantification of DetNet scheduling resources for all queueing mechanisms, and defines the IGP advertisement method. DetNet scheduling resources can be used for admission check when set up a new DetNet flow in the network. This document specifies the advertisement of DetNet scheduling resources in BGP-LS, providing a foundation for the controller to calculate DetNet based traffic engineering path. 1.1. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 2. Advertising DetNet Scheduling Capability The DetNet Scheduling Capability TLV is a BGP-LS Link Attribute TLV associated with the Link NLRI that is used for the advertisement of the DetNet scheduling capability associated with a link. The format of this TLV is as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ST | Flags | Scheduling Capability Info // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: DetNet Scheduling Capbility TLV where: * Type: TBD. * Length: variable, depending on size of the Scheduling Capability Info field. * ST (Scheduling Type): 1 byte, represents the type of scheduling mechanism supported by the link, as below. Peng Expires 12 July 2026 [Page 3] Internet-Draft BGP-LS Adv DetNet Resources January 2026 - 0: Reserved for default or unspecified scheduling mechanisms, such as SP (strict priority) that is widely used in the network. It is not recommended to explicitly advertise the detailed capability information of default scheduling mechanisms by the DetNet Scheduling Capability Sub-TLV. - 1: ATS[IEEE802.1Qcr]. - 2: CBS[IEEE802.1Qav]. - 3: ATS+CBS[ATSplusCBS]. - 4: ECQF[IEEE802.1Qdv]/TCQF[I-D.eckert-detnet-tcqf]. - 5: EDF[I-D.peng-detnet-deadline-based-forwarding]. - 6: TQF[I-D.peng-detnet-packet-timeslot-mechanism]. - 7: C-SCORE[I-D.joung-detnet-stateless-fair-queuing]. - 8: gLBF[I-D.eckert-detnet-glbf]. - 9~255: To be defined in the future. * Flags: 1 byte, currently two flags are defined as below: - I (In-time mode): indicates whether the scheduling mechanism supports in-time scheduling mode. Support if set, otherwise not support. In-time scheduling mode can be understood as sending the packet as soon as possible before its bounded latency per-hop. - O (On-time mode): indicates whether the scheduling mechanism supports on-time scheduling mode. Support if set, otherwise not support. On-time scheduling mode can be understood as sending the packet as close as possible to its bounded latency per-hop. * Scheduling Capability Info: Includes capability level information corresponding to the specific scheduling mechanism type with variable size. - If ST is one of ATS, CBS, ATS+CBS, or gLBF, the field size is 1 byte, and it contains the number (i.e., n) of traffic classes supported by the scheduling mechanism. Let the first traffic class be 0, the last traffic class be n-1, with ascending priority order from traffic class 0 to traffic class n-1. Peng Expires 12 July 2026 [Page 4] Internet-Draft BGP-LS Adv DetNet Resources January 2026 - If ST is ECQF/TCQF, the field size is n*2 bytes, and it contains n cycle durations, each with 2 bytes, in unit of microseconds. For example, the cycle duration may be 10 us, or 20 us, and so on. Different cycle durations represent different CQF instances. - If ST is EDF, the field size is 6 bytes, and it contains the minimum delay level (2 bytes, in unit of microseconds), maximum delay level (2 bytes, in unit of microseconds), and delay level interval (2 bytes, in unit of microseconds) supported by the EDF scheduling mechanism. The number of supported delay levels can be deduced by n = (maximum delay level - minimum delay level) / delay level interval + 1. For example, the minimum delay level may be 10 us, the maximum delay level may be 100 us, and the delay level interval may be 10 us. - If ST is TQF, the field size is n*8 bytes, and it contains n TQF instances, each with 8 bytes. These 8 bytes specifically include the Orchestration Period Length (4 bytes, in unit of microseconds), the amount of timeslots N (2 bytes) within the Orchestration Period, and the amount of timeslots M (2 bytes) within the Scheduling Period. The timeslot length can be deduced by Orchestration Period Length / N. For example, the Orchestration Period Length may be 1000 us, containing 100 timeslots, and the Scheduling Period may contain fewer timeslots, such as 10. - If ST is C-SCORE, the field size is zero, and there is no need to specify capability level information. It can be considered to support a single instance. The DetNet Scheduling Capbility TLV MAY be advertised more than once in the BGP-LS Attribute, one for each scheduling type. If multiple instances are present for the same scheduling type, then the first one MUST be considered valid, and the rest MUST be ignored. 3. Advertising DetNet Maximum Reservable Bandwidth The DetNet Maximum Reservable Bandwidth TLV is a BGP-LS Link Attribute TLV associated with the Link NLRI that is used for the advertisement of the maximum reservable bandwidth of specific scheduling mechanism associated with a link. The format of this TLV is as follows: Peng Expires 12 July 2026 [Page 5] Internet-Draft BGP-LS Adv DetNet Resources January 2026 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ST | Maximum Reservable Bandwidth // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: DetNet Maximum Reservable Bandwidth TLV where: * Type: TBD. * Length: variable, depending on size of the Maximum Reservable Bandwidth field. * ST (Scheduling Type): 1 byte, represents the type of scheduling mechanism supported by the link. * Maximum Reservable Bandwidth: includes the maximum reservable bandwidth (MRBan) corresponding to the specific scheduling mechanism type with variable size, depending on the ST. - If ST is one of ATS, CBS, ATS+CBS, or gLBF, the field size is n*4 bytes, and it contains the MRBan per traffic class (4 bytes, in the unit of bytes per second in IEEE floating point format), from traffic class 0 to traffic class n-1. - If ST is CQF/ECQF, the field size is n*6 bytes, and it contains n tuple , where, cycle duration in the unit of microseconds, and MRBan in the unit of bytes per second in IEEE floating point format. - If ST is EDF, the field size is n*6 bytes, and it contains n tuple , where, delay level in the unit of microseconds, and MRBan in the unit of bytes per second in IEEE floating point format. Note that all delay levels' maximum reservable bandwidth must meet the schedulability condition. - If ST is TQF, the field size is n*8 bytes, and it contains n tuple , where, OPL (Orchestration Period Length) in the unit of microseconds, and MRBan in the unit of bytes per second in IEEE floating point format. Peng Expires 12 July 2026 [Page 6] Internet-Draft BGP-LS Adv DetNet Resources January 2026 - If ST is C-SCORE, the field size is 4 bytes, and it contains the MRBan in the unit of bytes per second in IEEE floating point format. The DetNet Maximum Reservable Bandwidth TLV MAY be advertised more than once in the BGP-LS Attribute, one for each scheduling type. If multiple instances are present for the same scheduling type, then the first one MUST be considered valid, and the rest MUST be ignored. 4. Advertising DetNet Unreserved Bandwidth The DetNet Maximum Reservable Bandwidth TLV is a BGP-LS Link Attribute TLV associated with the Link NLRI that is used for the advertisement of the unreserved bandwidth of specific scheduling mechanism associated with a link. The format of this TLV is as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ST | Unreserved Bandwidth // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: DetNet Unreserved Bandwidth TLV where: * Type: TBD. * Length: variable, depending on size of the Unreserved Bandwidth field. * ST (Scheduling Type): 1 byte, represents the type of scheduling mechanism supported by the link. * Unreserved Bandwidth: includes the unreserved bandwidth (UBan) corresponding to the specific scheduling mechanism type with variable size, depending on the ST. - If ST is one of ATS, CBS, ATS+CBS, or gLBF, the field size is n*4 bytes, and it contains the UBan per traffic class (4 bytes, in the unit of bytes per second in IEEE floating point format), from traffic class 0 to traffic class n-1. Peng Expires 12 July 2026 [Page 7] Internet-Draft BGP-LS Adv DetNet Resources January 2026 - If ST is CQF/ECQF, the field size is n*6 bytes, and it contains n tuple , where, cycle duration in the unit of microseconds, and UBan in the unit of bytes per second in IEEE floating point format. - If ST is EDF, the field size is n*6 bytes, and it contains n tuple , where, delay level in the unit of microseconds, and UBan in the unit of bytes per second in IEEE floating point format. - If ST is TQF, the field size is n*8 bytes, and it contains n tuple , where, OPL (Orchestration Period Length) in the unit of microseconds, and UBan in the unit of bytes per second in IEEE floating point format. - If ST is C-SCORE, the field size is 4 bytes, and it contains the UBan in the unit of bytes per second in IEEE floating point format. The DetNet Unreserved Bandwidth TLV MAY be advertised more than once in the BGP-LS Attribute, one for each scheduling type. If multiple instances are present for the same scheduling type, then the first one MUST be considered valid, and the rest MUST be ignored. 5. Advertising DetNet Maximum Reservable Burst The DetNet Maximum Reservable Burst TLV is a BGP-LS Link Attribute TLV associated with the Link NLRI that is used for the advertisement of the maximum reservable burst of specific scheduling mechanism associated with a link. The format of this TLV is as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ST | Maximum Reservable Burst // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4: DetNet Maximum Reservable Burst TLV where: * Type: TBD. Peng Expires 12 July 2026 [Page 8] Internet-Draft BGP-LS Adv DetNet Resources January 2026 * Length: variable, depending on size of the Maximum Reservable Burst field. * ST (Scheduling Type): 1 byte, represents the type of scheduling mechanism supported by the link. * Maximum Reservable Burst: includes the maximum reservable burst (MRBur) corresponding to the specific scheduling mechanism type with variable size, depending on the ST. - If ST is one of ATS, CBS, ATS+CBS, or gLBF, the field size is n*4 bytes, and it contains the MRBur per traffic class (4 bytes, in the unit of bytes), from traffic class 0 to traffic class n-1. - If ST is CQF/ECQF, the field size is n*6 bytes, and it contains n tuple , where, cycle duration in the unit of microseconds, and MRBur in the unit of bytes. Note that MRBur represents the resources of the entire CQF instance, not the resources of a specific cycle (or bin) under that instance (e.g., a CQF instance may configure 3-bin mode, with bin a, b, c). - If ST is EDF, the field size is n*6 bytes, and it contains n tuple , where, delay level in the unit of microseconds, and MRBur in the unit of bytes. Note that all delay levels' maximum reservable burst must meet the schedulability condition equation. - If ST is TQF, the field size is n*8 bytes, and it contains n tuple , where, OPL (Orchestration Period Length) in the unit of microseconds, and MRBur in the unit of bytes. Note that MRBur represents resources for individual timeslot within the Orchestration Period, and in general all timeslots have the same MRBur value. - If ST is C-SCORE, the field size is 4 bytes, and it contains the MRBur in the unit of bytes. The DetNet Maximum Reservable Burst TLV MAY be advertised more than once in the BGP-LS Attribute, one for each scheduling type. If multiple instances are present for the same scheduling type, then the first one MUST be considered valid, and the rest MUST be ignored. Peng Expires 12 July 2026 [Page 9] Internet-Draft BGP-LS Adv DetNet Resources January 2026 6. Advertising DetNet Unreserved Burst The DetNet Maximum Unreserved Burst TLV is a BGP-LS Link Attribute TLV associated with the Link NLRI that is used for the advertisement of the unreserved burst of specific scheduling mechanism associated with a link. The format of this TLV is as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ST | Unreserved Burst // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 5: DetNet Unreserved Burst TLV where: * Type: TBD. * Length: variable, depending on size of the Unreserved Burst field. * ST (Scheduling Type): 1 byte, represents the type of scheduling mechanism supported by the link. * Unreserved Burst: includes the unreserved burst (UBur) corresponding to the specific scheduling mechanism type with variable size, depending on the ST. - If ST is one of ATS, CBS, ATS+CBS, or gLBF, the field size is n*4 bytes, and it contains the UBur per traffic class (4 bytes, in the unit of bytes), from traffic class 0 to traffic class n-1. - If ST is CQF/ECQF, the field size is n*6 bytes, and it contains n tuple , where, cycle duration in the unit of microseconds, and UBur in the unit of bytes. Note that UBur represents the resources of the entire CQF instance, not the resources of a specific cycle (or bin) under that instance (e.g., a CQF instance may configure 3-bin mode, with bin a, b, c). - If ST is EDF, the field size is n*6 bytes, and it contains n tuple , where, delay level in the unit of microseconds, and UBur in the unit of bytes. Peng Expires 12 July 2026 [Page 10] Internet-Draft BGP-LS Adv DetNet Resources January 2026 - If ST is TQF, the field size is 4+k*6 bytes, and it contains OPL(4B) and k (k <= N) tuple , where, OPL (Orchestration Period Length) in the unit of microseconds, and UBur in the unit of bytes. Note that UBur represents resources for individual timeslot within the Orchestration Period. - If ST is C-SCORE, the field size is 4 bytes, and it contains the UBur in the unit of bytes. The DetNet Unreserved Burst TLV MAY be advertised more than once in the BGP-LS Attribute, one for each scheduling type. If multiple instances are present for the same scheduling type, then the first one MUST be considered valid, and the rest MUST be ignored, except that TQF may advertise multiple DetNet Unreserved Burst TLV each for a set of timeslots. 7. Advertising DetNet Timeslot Mapping The DetNet Timeslot Mapping TLV is a BGP-LS Link Attribute TLV associated with the Link NLRI that is used for the advertisement of the timeslot mapping relationship associated with a link. This mapping represents a timeslot id (e.g, x) of the output port of the local node, after link propagation delay, falls into the timeslot id (e.g, y) of the incomming port of the remote node. The format of this TLV is as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | Local Timeslot ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Remote Timeslot ID | Remaining Time | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Period Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 6: DetNet Timeslot Mapping TLV where: * Type: TBD. * Length: 12. Peng Expires 12 July 2026 [Page 11] Internet-Draft BGP-LS Adv DetNet Resources January 2026 * Reserved: 2 octet field that MUST be set to 0 by the originator and ignored by the receiver. * Local Timeslot ID: 2 octet field that represents the type of scheduling mechanism supported by the link. * Remote Timeslot ID: 2 octet field that represents the timeslot id of the incomming port of the remote node that mapped by Local Timeslot ID. * Remaining Time: 2 octet field that represents the offset between the end of the Local Timeslot ID and the end of the Remote Timeslot ID. * Period Length: 4 octet field that represents the dinstinguisher of the instance which contains multiple consecutive cyclic timeslots. The DetNet Timeslot Mapping TLV SHOULD be advertised once at most for each period length enabled on the link. If multiple instances are present for the same period length, then the first one MUST be considered valid, and the rest MUST be ignored. 8. Advertising DetNet Period Mapping The DetNet Period Mapping TLV is a BGP-LS Link Attribute TLV associated with the Link NLRI that is used for the advertisement of the period mapping relationship associated with a link. This mapping represents the end of the period of the output port of the local node, after link propagation delay, falls into the period of the incomming port of the remote node. The format of this TLV is as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Period Offset | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Period Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 7: DetNet Period Mapping TLV where: Peng Expires 12 July 2026 [Page 12] Internet-Draft BGP-LS Adv DetNet Resources January 2026 * Type: TBD. * Length: 8. * Period Offset: 4 octet field that represents the offset between the end of the local period and the end of the remote period. * Period Length: 4 octet field that represents the dinstinguisher of the instance which contains multiple consecutive cyclic timeslots. The DetNet Period Mapping TLV SHOULD be advertised once at most for each period length enabled on the link. If multiple instances are present for the same period length, then the first one MUST be considered valid, and the rest MUST be ignored. 9. Advertising DetNet Intra-node Forwarding Delay The DetNet Intra-node Forwarding Delay TLV is a BGP-LS Node Attribute TLV associated with the Node NLRI that is used for the maximum intra- node forwarding delay associated with a given node. It represents the maximum forwarding delay experienced by a packet from the node's incomming port (or the control plane of this node) to the output port, depending on the node's implementation. The format of this TLV is as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Intra-node Forwarding Delay | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 8: DetNet Intra-node Forwarding Delay TLV where: * Type: TBD. * Length: 4. * Intra-node Forwarding Delay: 4 octet field that represents the maximum forwarding delay experienced by a packet from the node's incomming port (or the control plane of this node) to the output port. Peng Expires 12 July 2026 [Page 13] Internet-Draft BGP-LS Adv DetNet Resources January 2026 The DetNet Intra-node Forwarding Delay TLV SHOULD be advertised once at most. If multiple instances are present, then the first one MUST be considered valid, and the rest MUST be ignored. 10. Operations The controller calculate a DetNet path for the service flow in the network that satisfies RSspec, using a specific scheduling mechanism type based on the resources collected from all links in the network. The unreserved resources of each link in the path should cover the TSpec of the service flow. Choosing continuous links with the same mechanism can achieve better DetNet QoS. Choosing heterogeneous scheduling mechanisms for path calculation usually occurs across domains, where different domains use different scheduling mechanisms. The controller must furtherly specify the capability level of each link for the service flow. In general, the same capability level (such as the same traffic class) can be used on all links, however, different capability levels is also possible. It is the unreserved resources corresponding to the specific capability level should cover the TSpec of the service flow. Once the path is calculated, the controller reserve the bandwidth and burst resources from the locally maintained database. 11. IANA Considerations This document try to allocate code points from the "BGP-LS NLRI and Attribute TLVs" sub-registry of the "Border Gateway Protocol - Link- State (BGP-LS) Parameters" registry group as follows: +--------+------------------------------------------+---------------+ | Code | | | | Point | Description | Reference | +--------+------------------------------------------+---------------+ | TBD1 | DetNet Maximum Reservable Bandwidth | this document | | TBD2 | DetNet Unreserved Bandwidth | this document | | TBD3 | DetNet Maximum Reservable Burst | this document | | TBD4 | DetNet Unreserved Burst | this document | | TBD5 | DetNet Timeslot Mapping | this document | | TBD6 | DetNet Periold Mapping | this document | | TBD7 | DetNet Intra-node Forwarding Delay | this document | +--------+------------------------------------------+---------------+ 12. Security Considerations This document does not introduce any new security considerations beyond those covered by [RFC9552]. Peng Expires 12 July 2026 [Page 14] Internet-Draft BGP-LS Adv DetNet Resources January 2026 13. Acknowledgements TBD 14. References 14.1. Normative References [I-D.eckert-detnet-glbf] Eckert, T. T., Clemm, A., Bryant, S., and S. Hommes, "Deterministic Networking (DetNet) Data Plane - guaranteed Latency Based Forwarding (gLBF) for bounded latency with low jitter and asynchronous forwarding in Deterministic Networks", Work in Progress, Internet-Draft, draft-eckert- detnet-glbf-07, 11 December 2025, . [I-D.eckert-detnet-tcqf] Eckert, T. T., Li, Y., Bryant, S., Malis, A. G., Ryoo, J., Liu, P., Li, G., and S. Ren, "Deterministic Networking (DetNet) Data Plane - Tagged Cyclic Queuing and Forwarding (TCQF) for bounded latency with low jitter in large scale DetNets", Work in Progress, Internet-Draft, draft-eckert- detnet-tcqf-12, 15 December 2025, . [I-D.joung-detnet-stateless-fair-queuing] Joung, J., Ryoo, J., Cheung, T., Li, Y., and P. Liu, "Latency Guarantee with Stateless Fair Queuing", Work in Progress, Internet-Draft, draft-joung-detnet-stateless- fair-queuing-06, 22 December 2025, . [I-D.peng-detnet-deadline-based-forwarding] Peng, S., Du, Z., Basu, K., cheng, C., Yang, D., and C. Liu, "Deadline Based Deterministic Forwarding", Work in Progress, Internet-Draft, draft-peng-detnet-deadline- based-forwarding-18, 13 October 2025, . [I-D.peng-detnet-packet-timeslot-mechanism] Peng, S., Liu, P., Basu, K., Liu, A., Yang, D., Peng, G., and J. Zhao, "Timeslot Queueing and Forwarding Mechanism", Work in Progress, Internet-Draft, draft-peng-detnet- Peng Expires 12 July 2026 [Page 15] Internet-Draft BGP-LS Adv DetNet Resources January 2026 packet-timeslot-mechanism-13, 12 October 2025, . [I-D.peng-lsr-deterministic-traffic-engineering] Peng, S., "IGP Extensions for Deterministic Traffic Engineering", Work in Progress, Internet-Draft, draft- peng-lsr-deterministic-traffic-engineering-04, 8 January 2026, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8655] Finn, N., Thubert, P., Varga, B., and J. Farkas, "Deterministic Networking Architecture", RFC 8655, DOI 10.17487/RFC8655, October 2019, . [RFC9552] Talaulikar, K., Ed., "Distribution of Link-State and Traffic Engineering Information Using BGP", RFC 9552, DOI 10.17487/RFC9552, December 2023, . 14.2. Informative References [ATSplusCBS] "Latency and Backlog Bounds in Time-Sensitive Networking with Credit Based Shapers and Asynchronous Traffic Shaping", 2018, . [IEEE802.1Qav] "IEEE Standard for Local and metropolitan area networks -- Virtual Bridged Local Area Networks - Amendment 12: Forwarding and Queuing Enhancements for Time-Sensitive Streams", 2010, . Peng Expires 12 July 2026 [Page 16] Internet-Draft BGP-LS Adv DetNet Resources January 2026 [IEEE802.1Qcr] "IEEE Standard for Local and Metropolitan Area Networks-- Bridges and Bridged Networks Amendment 34:Asynchronous Traffic Shaping", 2020, . [IEEE802.1Qdv] "Draft Standard for Local and metropolitan area networks-- Enhancements to Cyclic Queuing and Forwarding", 2023, . [Net-Calculus] "Network Calculus: A Theory of Deterministic Queuing Systems for the Internet", 2001, . Author's Address Shaofu Peng ZTE Corporation China Email: peng.shaofu@zte.com.cn Peng Expires 12 July 2026 [Page 17]