Internet-Draft Echo Request/Reply for DetNet Capability February 2024
Zhang, et al. Expires 21 August 2024 [Page]
Workgroup:
detnet Working Group
Internet-Draft:
draft-tan-detnet-cap-discovery-01
Published:
Intended Status:
Standards Track
Expires:
Authors:
L. Zhang
Huawei
H. Huang
Huawei
T. Zhou
Huawei

Echo Request/Reply for DetNet Capability Discovery

Abstract

This document describes an extension to the echo request/reply mechanisms used in IP, MPLS or other DetNet data plane environments, which can be used within the DetNet domain, allowing the ping initiator node to discover the enabled DetNet capabilities of each relay node of detnet service-sub layer, which including discovering DetNet relay nodes, collecting DetNet service sub-layer specific information from DetNet relay nodes, as well as discovering the locations of PREOF functions.

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 21 August 2024.

1. Introduction

[RFC8655] provides the overall architecture for Deterministic Networking (DetNet), which provides a capability to carry specified unicast or multicast data flows for real-time applications with extremely low data loss rates and bounded latency within a network domain. Currently DetNet operates on IP and MPLS data plane.

DetNet functionality is divided into two sub-layers. The DetNet service sub-layer provides DetNet service protection with functionalities and operation of PREOF, a collective name for Packet Replication, Elimination, and Ordering Functions. The DetNet forwarding sub-layer provides resource allocation for DetNet flows over paths provided by the underlying network.

[I-D.ietf-detnet-oam-framework] details the specific requirements of the Operation, Administration, and Maintenance (OAM) recommended to maintain a deterministic network. OAM for the DetNet MPLS data plane is described in [I-D.ietf-detnet-mpls-oam] and OAM for the DetNet IP data plane is described in [I-D.ietf-detnet-ip-oam].

[I-D.ietf-detnet-oam-framework] described the DetNet service sub-layer oam requirements of discovering DetNet relay nodes , collecting DetNet service sub-layer specific (e.g., configuration/operation/status) information from DetNet relay nodes, as well as discovering the locations of PREOF functions.

These requirements, could be satisfied using alternative technologies like NETCONF/YANG, IGP flooding or ping/traceroute. [I-D.varga-detnet-service-sub-layer-oam] introduced a ping/traceroute method, "DetNet Ping", and mentions that it could be used for discovering DetNet capabilities of DetNet relay nodes.

This document introduced extensions to DetNet Ping (echo request/reply) used in IP, MPLS or other DetNet data plane environments, which can be used within the DetNet domain, allowing the ping initiator node to discover the enabled DetNet capabilities of each relay node of detnet service-sub layer.

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.

1.2. Terminology

The abbreviations used in this document are:

DetNet: Deterministic Networking

OAM: Operation, Administration, and Maintenance

PRF: Packet Replication Function

PEF: Packet Elimination Function

POF: Packet Ordering Function

PREOF: Packet Replication, Elimination and Ordering Function

2. DetNet Capability Discovery

2.1. DetNet Capability Discovery Operation

Once the DetNet PING initiator node is triggered to discover the enabled DetNet capabilities of each DetNet relay node, the initiator node will send DetNet echo requests that include the DetNet Capabilities Discovery Header.
First, with TTL equal to 1 to reach the closest node, which may be an DetNet relay node or not. Then with TTL equal to 2 to reach the second nearest node, which also may be an DetNet relay node or not.
And further, increasing by 1 the TTL every time the initiator node sends a new echo request. As a result, the echo requests sent by the initiator node will reach all nodes one by one along the transport path of DetNet service flow.
Alternatively, if the initiator node knows precisely all the DetNet relay nodes beforehand, once the initiator node is triggered to discover the enabled DetNet capabilities, it can send an echo request to each DetNet relay node directly, without TTL expiration.

2.2. DetNet Capability Discovery Header

For echo DetNet request/reply message used for DetNet capability discovery, DetNet capabilities information are delivered by several kinds of DetNet Capabilities Discovery Objects. This document introduces an abstract header which has the corresponding format depending on the type of DetNet data plane. The format of DetNet Capabilities Discovery Object is shown as below.

     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
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    .                                                               .
    .            DetNet Capabilities Discovery Header               .
    .                                                               .
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    .                                                               .
    .            DetNet Capabilities Discovery Data                 .
    .                                                               .
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: The Format of Mandatory Section of A BFD Control Packet
DetNet Capabilities Discovery Header: abstract header of DetNet Capabilities Discovery Object, with varied length and format depending on the type of DetNet data plane.
DetNet Capabilities Discovery Data: detailed information of DetNet Capabilities Discovery Object, with fixed length and format depending on the type of Detnet capability.

2.3. DetNet Capabilities Discovery Objects

2.3.1. DetNet Capability Object

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                                                               .
     .            DetNet Capabilities Discovery Header               .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                   DetNet Capability Flags             |S|F|I|O|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: DetNet Capability Object Format
Flags (4 bytes): DetNet Capability Flags
 * S: Service sub-layer capability
 * F: Forwarding sub-layer capability
 * I: Incoming flow configuration
 * O: Outgoing flow configuration

2.3.2. DetNet Relay Node Identifier Object

2.3.2.1. DetNet Node Identifier Object (MPLS)
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                                                               .
     .            DetNet Capabilities Discovery Header               .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                 Node ID               |     RESERVED    | OP  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: DetNet Node Identifier Object (MPLS) Format
  Node ID (20 bits): The value of the Node ID field identifies the DetNet node that originated the packet. It is same as defined in {{I-D.ietf-detnet-mpls-oam}}.
  OP (3 bits): Service operation on the node.
               0x00: No operation for DetNet service sub-layer
               0x01: Initiation for DetNet service sub-layer encapsulation
               0x02: Termination for DetNet service sub-layer encapsulation
               0x03: Relay(Swap) operation for DetNet service sub-layer
2.3.2.2. DetNet Node Identifier Object (IPv4)
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                                                               .
     .            DetNet Capabilities Discovery Header               .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                   IPv4 address (4 bytes)                      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | Prefix Length |                   RESERVED              | OP  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: DetNet Node Identifier Object (IPv4) Format
  IPv4 address(4 bytes): An IPv4 address. This address is treated as a prefix based on the prefix length value.
  Prefix length(1 bytes): Length in bits of the IPv4 prefix.
  OP (3 bits): Service operation on the node.
               0x00: No operation for DetNet service sub-layer
               0x01: Initiation for DetNet service sub-layer encapsulation
               0x02: Termination for DetNet service sub-layer encapsulation
               0x03: Relay(Swap) operation for DetNet service sub-layer
2.3.2.3. DetNet Node Identifier Object (IPv6)
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                                                               .
     .            DetNet Capabilities Discovery Header               .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                   IPv6 address (16 bytes)                     |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | Prefix Length |                   RESERVED              | OP  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: DetNet Node Identifier Object (IPv6) Format
  IPv6 address: An IPv6 address. This address is treated as a prefix based on the prefix length value.
  Prefix length: Length in bits of the IPv6 prefix.
  OP (3 bits): Service operation on the node.
               0x00: No operation for DetNet service sub-layer
               0x01: Initiation for DetNet service sub-layer encapsulation
               0x02: Termination for DetNet service sub-layer encapsulation
               0x03: Relay(Swap) operation for DetNet service sub-layer

2.3.3. DetNet service protection function objects

2.3.3.1. Service Protection Object
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                                                               .
     .            DetNet Capabilities Discovery Header               .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                              flags                  | OP  |SL |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: Service Protection Object Format
 flags (4 bytes): service protection flags.
  * SL (2 bits): Sequence number length.
                 0b00: no sequence number
                 0b01: sequence number length of 16 bits
                 0b10: sequence number length of 28 bits
2.3.3.2. Replication Capability Object
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                                                               .
     .            DetNet Capabilities Discovery Header               .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                              flags                            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 7: Replication Capability Object Format
 Flags (4 bytes): unused.
2.3.3.3. Elimination Capability Object
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                                                               .
     .            DetNet Capabilities Discovery Header               .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                              flags                            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 8: Elimination Capability Object Format
 Flags (4 bytes): unused.
2.3.3.4. Ordering Capability Object
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                                                               .
     .            DetNet Capabilities Discovery Header               .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                              flags                            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 9: Ordering Capability Object Format
 Flags (4 bytes): unused.

2.3.4. DetNet Service Flow Information Objects

2.3.4.1. DetNet Service Flow Identifier Object (MPLS)
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                                                               .
     .            DetNet Capabilities Discovery Header               .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                             Flags                       |P|I|O|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 10: DetNet Service Flow Identifier Object Format
Flags (4 bytes):
 * I: Incoming flow
 * O: Outgoing flow
 * P: platform-label-space
2.3.4.2. Service Label Object
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                                                               .
     .            DetNet Capabilities Discovery Header               .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                        Service Label                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 11: Service Label Object Format
Service Label (4 bytes): S-Label, DetNet Service identifier with MPLS data plane.
2.3.4.3. DetNet Service Flow Identifier Object (IPv4)
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                                                               .
     .            DetNet Capabilities Discovery Header               .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                             Flags                     |S|A|I|O|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 12: DetNet Service Flow Identifier Object (IPv4) Object Format
Flags (4 bytes):
 * I: Incoming flow
 * O: Outgoing flow
 * A: IPv4 flow identifier, including Source Address, Destination Address, Source Port, Destination Port, Protocol and Dscp
 * S: IPSec-spi
2.3.4.4. IPv4 Flow Identifier Object
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                                                               .
     .            DetNet Capabilities Discovery Header               .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                        Source Address                         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                     Destination Address                       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |         Source Port           |      Destination Port         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Protocol    |     Dscp      |           RESERVED            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 13: IPv4 Flow Identifier Object Format
Source Address (4 bytes): IPv4 source address of the packet.
Destination Address (4 bytes): IPv4 destination address of the packet.
Source Port (2 bytes): Source port of the packet.
Destination Port (2 bytes): Destination port of the packet.
Protocol (1 byte): Protocol of the packet.
Dscp (1 byte): Differentiated Services Code Point.
2.3.4.5. DetNet Service Flow Identifier Object (IPv6)
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                                                               .
     .            DetNet Capabilities Discovery Header               .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                             Flags                   |L|S|A|I|O|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 14: DetNet Service Flow Identifier Object (IPv6) Object Format
Flags (4 bytes):
 * I: Incoming flow
 * O: Outgoing flow
 * A: IPv6 flow identifier, including Source Address, Destination Address, Source Port, Destination Port, Protocol and Dscp
 * S: IPSec-spi
 * L: IPv6 flow label
2.3.4.6. IPv6 Flow Identifier Object
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                                                               .
     .            DetNet Capabilities Discovery Header               .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     +                                                               +
     |                                                               |
     +                         Source Address                        +
     |                                                               |
     +                                                               +
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     +                                                               +
     |                                                               |
     +                       Destination Address                     +
     |                                                               |
     +                                                               +
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |         Source Port           |      Destination Port         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Protocol    |     Dscp      |           RESERVED            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 15: IPv6 Flow Identifier Object Format
Source Address (16 bytes): IPv6 source address of the packet.
Destination Address (16 bytes): IPv6 destination address of the packet.
Source Port (2 bytes): Source port of the packet.
Destination Port (2 bytes): Destination port of the packet.
Protocol (1 byte): Protocol of the packet.
Dscp (1 byte): Differentiated Services Code Point.
2.3.4.7. IPv6 Flow Label Object
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                                                               .
     .            DetNet Capabilities Discovery Header               .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                         IPv6 Flow Label                       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 16: IPv6 Flow Label Object Format
IPv6 Flow Label (4 bytes): The flow label value of the header. IPv6 only.
2.3.4.8. IPSec-SPI Object
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                                                               .
     .            DetNet Capabilities Discovery Header               .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |              IPsec Security Parameters Index                  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 17: IPSec-SPI Object Format
IPSec-SPI (4 bytes): IPsec Security Parameters Index

2.4. DetNet Data Plane Considerations

2.4.1. MPLS Data Plane

DetNet echo request/reply messages in MPLS data plane, could encapsulate DetNet Capabilities Discovery Objects with typical TLV header format in place of the "DetNet Capabilities Discovery Header", as defined in {#detnet-cap-disc-obj}. The values of tlv types had not been defined yet.

      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              |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 18: MPLS TLV Header Format
Type (2 bytes): Tlv type
Length (2 bytes): Tlv Length
      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              |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                                                               .
     .            DetNet Capabilities Discovery Data                 .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 19: DetNet Capabilities Discovery Object (MPLS) Format

4. Security Considerations

The security considerations described in [RFC8655] apply to the extensions defined in this document as well. This document does not raise new security issues.

5. References

5.1. Normative References

[RFC8655]
Finn, N., Thubert, P., Varga, B., and J. Farkas, "Deterministic Networking Architecture", RFC 8655, DOI 10.17487/RFC8655, , <https://www.rfc-editor.org/rfc/rfc8655>.
[I-D.ietf-detnet-oam-framework]
Mirsky, G., Theoleyre, F., Papadopoulos, G. Z., Bernardos, C. J., Varga, B., and J. Farkas, "Framework of Operations, Administration and Maintenance (OAM) for Deterministic Networking (DetNet)", Work in Progress, Internet-Draft, draft-ietf-detnet-oam-framework-11, , <https://datatracker.ietf.org/doc/html/draft-ietf-detnet-oam-framework-11>.
[I-D.ietf-detnet-mpls-oam]
Mirsky, G., Chen, M., and B. Varga, "Operations, Administration and Maintenance (OAM) for Deterministic Networks (DetNet) with MPLS Data Plane", Work in Progress, Internet-Draft, draft-ietf-detnet-mpls-oam-15, , <https://datatracker.ietf.org/doc/html/draft-ietf-detnet-mpls-oam-15>.
[I-D.ietf-detnet-ip-oam]
Mirsky, G., Chen, M., and D. L. Black, "Operations, Administration, and Maintenance (OAM) for Deterministic Networks (DetNet) with IP Data Plane", Work in Progress, Internet-Draft, draft-ietf-detnet-ip-oam-13, , <https://datatracker.ietf.org/doc/html/draft-ietf-detnet-ip-oam-13>.
[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/rfc/rfc2119>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/rfc/rfc8174>.

5.2. Informative References

[I-D.varga-detnet-service-sub-layer-oam]
Varga, B., Farkas, J., and G. Mirsky, "Deterministic Networking (DetNet): OAM Functions for The Service Sub-Layer", Work in Progress, Internet-Draft, draft-varga-detnet-service-sub-layer-oam-03, , <https://datatracker.ietf.org/doc/html/draft-varga-detnet-service-sub-layer-oam-03>.

Authors' Addresses

Li Zhang
Huawei
China
Hongyi Huang
Huawei
China
Tianran Zhou
Huawei
China