RFC 8533

A YANG Data Model for Retrieval Methods for the Management of Operations, Administration, and Maintenance (OAM) Protocols That Use Connectionless Communications

πŸ“… published April 2019, from ietf

RFC 8533 πŸ’– A YANG Data Model for Retrieval Methods for the Management of Operations, Administration, and Maintenance (OAM) Protocols That Use Connectionless Communications

Okay bestie, let's get the deets first πŸ“‹βœ¨ This is RFC 8533, a Standards Track doc from April 2019 (ISSN 2070-1721). The authors are D. Kumar (Cisco), M. Wang, Q. Wu, Ed. (Huawei), R. Rahman, and S. Raghavan (Cisco). Q. Wu is the editor 🫢 The title page doesn't print an affiliation next to M. Wang or R. Rahman, so I'm not guessing πŸ™ˆ The title block also doesn't list anything it obsoletes or updates, so there's no drama there πŸ’…

Abstract ✨

This doc gives you a retrieval method YANG data model for connectionless OAM protocols πŸ¦‹ It's technology-independent, meaning it has RPC operations that work for any OAM protocol using connectionless communication. You can extend the model with technology-specific details if you need them πŸ”₯

Why is this iconic? Two big reasons πŸ‘‘ First, every OAM protocol ends up speaking the same language, so it's uniform. Second, it supports nested OAM workflows (doing OAM functions at different or the same levels through one unified interface) AND interactive OAM workflows (doing OAM functions at the same levels through one unified interface). Main character energy, fr fr πŸ’œ

Status of This Memo

Okay so this is an Internet Standards Track document 🌸

It's a product of the Internet Engineering Task Force (IETF), and it represents the consensus of the IETF community. It got public review and was approved for publication by the Internet Engineering Steering Group (IESG). If you want more info on Internet Standards, check Section 2 of RFC 7841 πŸ“š

For the current status of this doc, any errata, and how to give feedback, go to https://www.rfc-editor.org/info/rfc8533 🧚

Copyright time πŸ“œ Copyright (c) 2019 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 Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License 🫢

Table of Contents

1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
2.  Conventions Used in This document . . . . . . . . . . . . . .   3
  2.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   4
  2.2.  Tree Diagrams . . . . . . . . . . . . . . . . . . . . . .   4
3.  Overview of the Connectionless OAM Retrieval Methods Model  .   4
  3.1.  RPC Operation Definitions . . . . . . . . . . . . . . . .   4
  3.2.  OAM Retrieval Methods Hierarchy . . . . . . . . . . . . .   7
4.  OAM Retrieval Methods YANG Module . . . . . . . . . . . . . .  16
5.  Security Considerations . . . . . . . . . . . . . . . . . . .  26
6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  26
7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  27
  7.1.  Normative References  . . . . . . . . . . . . . . . . . .  27
  7.2.  Informative References  . . . . . . . . . . . . . . . . .  28
Appendix A.  Extending Connectionless OAM Method Module Example .  29
  A.1.  Example of New Retrieval Procedures Model . . . . . . . .  29
Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  40
Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  41

1. Introduction πŸŽ€

Operations, Administration, and Maintenance (OAM) are important networking functions that let operators do three things πŸ’…

  1. monitor network communications (i.e., reachability verification and Continuity Check) πŸ“‘
  2. troubleshoot failures (i.e., fault verification and localization) πŸ”
  3. monitor service-level agreements and performance (i.e., performance management) πŸ“ˆ

If you want an overview of OAM tools, [RFC7276] has you covered πŸ“–

Ping and Traceroute [RFC4443], plus Bidirectional Forwarding Detection (BFD) [RFC5880], are the well-known fault verification and isolation tools for IP networks [RFC792], respectively πŸ¦‹ Over the years, different technologies built similar toolsets for equivalent purposes. Same energy, different outfits πŸ‘—

This document presents an on-demand retrieval method YANG data model for OAM protocols that use connectionless communication. It's giving technology-independent RPC operations for connectionless OAM protocols (i.e., connectionless OAM) πŸ’– It's separated from the generic YANG data model for connectionless OAM [RFC8532], so the models for the retrieved data don't get mixed up with the retrieval procedures. It's expected that retrieval procedures will evolve faster than the data model [RFC8532], and they'll allow new procedures to be defined for retrieving the same data that the generic YANG data model for connectionless OAM defines 🌈

2. Conventions Used in This document ✨

The following terms are defined in [RFC6241] and are used in this document 🧚

  • client
  • configuration data
  • server
  • state data

The following terms are defined in [RFC6020] and are used in this document πŸ’œ

  • augment
  • data model
  • data node

The terminology for describing YANG data models is found in [RFC6020] πŸ“š

2.1. Terminology 🌸

TP - Test Point
MAC - Media Access Control
RPC - Remote Procedure Call
RPC Operation - A specific Remote Procedure Call

2.2. Tree Diagrams 🌿

Tree diagrams used in this document follow the notation defined in [RFC8340] πŸ¦‹

3. Overview of the Connectionless OAM Retrieval Methods Model πŸ’…

This document describes an on-demand retrieval method YANG data model for OAM protocols that use connectionless communication. It provides technology-independent retrieval procedures (RPC operations) for connectionless OAM protocols πŸ”₯ It's a flexible way to retrieve the data defined by the "ietf-connectionless-oam.yang" module [RFC8532] πŸŽ€

3.1. RPC Operation Definitions πŸ› οΈ

The RPC model lets you issue commands to a Network Configuration Protocol (NETCONF) server (in this case, the device that needs to execute the OAM command) and get a response back πŸ“¬

Under the "connectionless-oam-methods" module, we summarize common OAM functions and define two generic RPC operations: 'continuity-check' and 'path-discovery' 🫢 In practice, these RPC operations get activated on demand and are supported by corresponding technology-specific OAM tools [RFC7276]. For example, for the IP OAM model, the Continuity Check RPC corresponds to the IP Ping [RFC792] [RFC4443], while the path discovery RPC operation corresponds to IP Traceroute [RFC792] [RFC4443] ✨

Note that the RPC operation in this document is the base building block, which gets used to derive a model for a technology-specific OAM (i.e., ICMP Ping [RFC792] [RFC4443] and Label Switched Path (LSP) Ping [RFC8029]). This base building block should be extended with corresponding technology-specific parameters. To make future enhancements to data retrieval methods easier, the RPCs are captured under a separate module πŸ’–

The generic 'tp-address' grouping is used as data input from the different RPCs described in this document. The generic 'path-discovery-data' and 'continuity-check-data' groupings defined by the "ietf-connectionless-oam.yang" module [RFC8532] are used as data outputs from the different RPCs described in this document. Similar methods, including other RPCs, can retrieve the data using the same data model (i.e., the "ietf-connectionless-oam.yang" module) 🌈

     rpc continuity-check {
       if-feature cl-oam:continuity-check;
       description
         "Continuity Check RPC operation as per RFC 7276.";
       reference
         "RFC 7276: An Overview of Operations, Administration, and
          Maintenance (OAM) Tools";
       input {
       uses rpc-input-parameters;
       ....
       }
     output {
       container response-info {
         leaf protocol-id {
           type identityref {
             base protocol-id;
           }
           mandatory true;
           description
             "Protocol used in the Continuity Check. ";
         }
         leaf protocol-id-meta-data {
            type identityref {
             base protocol-id-meta-data;
             }
              description
              "An optional metadata related to the protocol ID.";
         }
         leaf status-code {

           type identityref{
          base status-code;
        }
           mandatory true;
           description
             "Status code for Continuity Check RPC operation.";
         }
         leaf status-sub-code {
           type identityref{
           base status-sub-code;
        }
           mandatory true;
           description
             "Status-sub-code for Continuity Check RPC operation.";
         }
         description
           "Status code and status-sub-code for Continuity Check RPC
            operation.";
       }
       uses cl-oam:continuity-check-data;
     }
   }

     rpc path-discovery {
       description
         "Path discovery RPC operation as per RFC 7276.";
       reference
         "RFC 7276: An Overview of Operations, Administration, and
          Maintenance (OAM) Tools";
       input {
       uses rpc-input-parameters;
       .....
       }
     output {
       list response-list {
         key "response-index";
         description
           "Path discovery response list.";
         leaf response-index {
           type uint32;
           mandatory true;
           description
             "Response index.";
         }
         leaf protocol-id {
           type identityref {
             base protocol-id;
           }
           mandatory true;
           description
             "Protocol used in path discovery. ";
         }
         leaf protocol-id-meta-data {
            type identityref {
             base protocol-id-meta-data;
             }
              description
              "An optional metadata related to the protocol ID.";
         }
         leaf status-code {
           type identityref{
           base status-code;
         }
           mandatory true;
           description
             "Status code for path discovery RPC operation. ";
         }
         leaf status-sub-code {
           type identityref{
           base status-sub-code;
        }
           mandatory true;
           description
             "Status-sub-code for path discovery RPC operation. ";
         }
       }
       uses cl-oam:path-discovery-data;
     }
   }

Snippet of Data Hierarchy Related to RPC Operations 🧩

3.2. OAM Retrieval Methods Hierarchy 🌳

The complete data hierarchy related to the Connectionless OAM Retrieval Methods YANG data model is presented below πŸ‘€

module: ietf-connectionless-oam-methods

Okay bestie, this is the RPC tree for the continuity-check and path-discovery operations, and it's giving full YANG-model main character energy πŸ¦‹βœ¨

     rpcs:
       +---x continuity-check {cl-oam:continuity-check}?
       |  +---w input
       |  |  +---w destination-tp
       |  |  |  +---w tp-location-type    identityref
       |  |  |  +---w mac-address
       |  |  |  |  +---w mac-address    yang:mac-address
       |  |  |  +---w ipv4-address
       |  |  |  |  +---w ipv4-address    inet:ipv4-address
       |  |  |  +---w ipv6-address
       |  |  |  |  +---w ipv6-address    inet:ipv6-address
       |  |  |  +---w tp-attribute
       |  |  |  |  +---w tp-attribute-type?
       |  |  |  |       address-attribute-type
       |  |  |  |  +---w (tp-attribute-value)?
       |  |  |  |     +--:(ip-prefix)
       |  |  |  |     |  +---w ip-prefix?
       |  |  |  |     |          inet:ip-prefix
       |  |  |  |     +--:(bgp)
       |  |  |  |     |  +---w bgp?
       |  |  |  |     |          inet:ip-prefix
       |  |  |  |     +--:(tunnel)
       |  |  |  |     |  +---w tunnel-interface?         uint32
       |  |  |  |     +--:(pw)
       |  |  |  |     |  +---w remote-pe-address?
       |  |  |  |     |  |       inet:ip-address
       |  |  |  |     |  +---w pw-id?                    uint32
       |  |  |  |     +--:(vpls)
       |  |  |  |     |  +---w route-distinguisher?
       |  |  |  |     |  |       rt:route-distinguisher
       |  |  |  |     |  +---w sender-ve-id?             uint16
       |  |  |  |     |  +---w receiver-ve-id?           uint16
       |  |  |  |     +--:(mpls-mldp)
       |  |  |  |        +---w (root-address)?
       |  |  |  |           +--:(ip-address)
       |  |  |  |           |  +---w source-address?
       |  |  |  |           |  |       inet:ip-address
       |  |  |  |           |  +---w group-ip-address?
       |  |  |  |           |          inet:ip-address
       |  |  |  |           +--:(vpn)
       |  |  |  |           |  +---w as-number?
       |  |  |  |           |          inet:as-number
       |  |  |  |           +--:(global-id)
       |  |  |  |              +---w lsp-id?             string
       |  |  |  +---w system-info
       |  |  |     +---w router-id?   rt:router-id
       |  |  +---w source-interface      if:interface-ref
       |  |  +---w outbound-interface    if:interface-ref
       |  |  +---w vrf?
       |  |  |       cl-oam:routing-instance-ref
       |  |  +---w session-type?         enumeration
       |  |  +---w count?                uint32
       |  |  +---w ttl?                  uint8
       |  |  +---w packet-size?          uint32
       |  +--ro output
       |     +--ro response-info
       |     |  +--ro protocol-id              identityref
       |     |  +--ro protocol-id-meta-data?   identityref
       |     |  +--ro status-code              identityref
       |     |  +--ro status-sub-code          identityref
       |     +--ro src-test-point
       |     |  +--ro ni?                 routing-instance-ref
       |     |  +--ro tp-location-type    identityref
       |     |  +--ro mac-address
       |     |  |  +--ro mac-address    yang:mac-address
       |     |  +--ro ipv4-address
       |     |  |  +--ro ipv4-address    inet:ipv4-address
       |     |  +--ro ipv6-address
       |     |  |  +--ro ipv6-address    inet:ipv6-address
       |     |  +--ro tp-attribute
       |     |  |  +--ro tp-attribute-type?
       |     |  |  |       address-attribute-type
       |     |  |  +--ro (tp-attribute-value)?
       |     |  |     +--:(ip-prefix)
       |     |  |     |  +--ro ip-prefix?
       |     |  |     |          inet:ip-prefix
       |     |  |     +--:(bgp)
       |     |  |     |  +--ro bgp?
       |     |  |     |          inet:ip-prefix
       |     |  |     +--:(tunnel)
       |     |  |     |  +--ro tunnel-interface?         uint32
       |     |  |     +--:(pw)
       |     |  |     |  +--ro remote-pe-address?
       |     |  |     |  |       inet:ip-address
       |     |  |     |  +--ro pw-id?                    uint32
       |     |  |     +--:(vpls)
       |     |  |     |  +--ro route-distinguisher?
       |     |  |     |  |       rt:route-distinguisher
       |     |  |     |  +--ro sender-ve-id?             uint16
       |     |  |     |  +--ro receiver-ve-id?           uint16
       |     |  |     +--:(mpls-mldp)
       |     |  |        +--ro (root-address)?
       |     |  |           +--:(ip-address)
       |     |  |           |  +--ro source-address?
       |     |  |           |  |       inet:ip-address
       |     |  |           |  +--ro group-ip-address?
       |     |  |           |          inet:ip-address
       |     |  |           +--:(vpn)
       |     |  |           |  +--ro as-number?
       |     |  |           |          inet:as-number
       |     |  |           +--:(global-id)
       |     |  |              +--ro lsp-id?             string
       |     |  +--ro system-info
       |     |  |  +--ro router-id?   rt:router-id
       |     |  +--ro egress-intf-name?   if:interface-ref
       |     +--ro dest-test-point
       |     |  +--ro ni?                  routing-instance-ref
       |     |  +--ro tp-location-type     identityref
       |     |  +--ro mac-address
       |     |  |  +--ro mac-address    yang:mac-address
       |     |  +--ro ipv4-address
       |     |  |  +--ro ipv4-address    inet:ipv4-address
       |     |  +--ro ipv6-address
       |     |  |  +--ro ipv6-address    inet:ipv6-address
       |     |  +--ro tp-attribute
       |     |  |  +--ro tp-attribute-type?
       |     |  |  |       address-attribute-type
       |     |  |  +--ro (tp-attribute-value)?
       |     |  |     +--:(ip-prefix)
       |     |  |     |  +--ro ip-prefix?
       |     |  |     |          inet:ip-prefix
       |     |  |     +--:(bgp)
       |     |  |     |  +--ro bgp?
       |     |  |     |          inet:ip-prefix
       |     |  |     +--:(tunnel)
       |     |  |     |  +--ro tunnel-interface?         uint32
       |     |  |     +--:(pw)
       |     |  |     |  +--ro remote-pe-address?
       |     |  |     |  |       inet:ip-address
       |     |  |     |  +--ro pw-id?                    uint32
       |     |  |     +--:(vpls)
       |     |  |     |  +--ro route-distinguisher?
       |     |  |     |  |       rt:route-distinguisher
       |     |  |     |  +--ro sender-ve-id?             uint16
       |     |  |     |  +--ro receiver-ve-id?           uint16
       |     |  |     +--:(mpls-mldp)
       |     |  |        +--ro (root-address)?
       |     |  |           +--:(ip-address)
       |     |  |           |  +--ro source-address?
       |     |  |           |  |       inet:ip-address
       |     |  |           |  +--ro group-ip-address?
       |     |  |           |          inet:ip-address
       |     |  |           +--:(vpn)
       |     |  |           |  +--ro as-number?
       |     |  |           |          inet:as-number
       |     |  |           +--:(global-id)
       |     |  |              +--ro lsp-id?             string
       |     |  +--ro system-info
       |     |  |  +--ro router-id?   rt:router-id
       |     |  +--ro ingress-intf-name?   if:interface-ref
       |     +--ro sequence-number?             uint64
       |     +--ro hop-cnt?                     uint8
       |     +--ro session-packet-statistics
       |     |  +--ro rx-packet-count?    uint32
       |     |  +--ro tx-packet-count?    uint32
       |     |  +--ro rx-bad-packet?      uint32
       |     |  +--ro tx-packet-failed?   uint32
       |     +--ro session-error-statistics
       |     |  +--ro packet-loss-count?          uint32
       |     |  +--ro loss-ratio?                 percentage
       |     |  +--ro packet-reorder-count?       uint32
       |     |  +--ro packets-out-of-seq-count?   uint32
       |     |  +--ro packets-dup-count?          uint32
       |     +--ro session-delay-statistics
       |     |  +--ro time-unit-value?       identityref
       |     |  +--ro min-delay-value?       uint32
       |     |  +--ro max-delay-value?       uint32
       |     |  +--ro average-delay-value?   uint32
       |     +--ro session-jitter-statistics
       |        +--ro unit-value?             identityref
       |        +--ro min-jitter-value?       uint32
       |        +--ro max-jitter-value?       uint32
       |        +--ro average-jitter-value?   uint32
       +---x path-discovery {cl-oam:path-discovery}?
          +---w input
          |  +---w destination-tp
          |  |  +---w tp-location-type    identityref
          |  |  +---w mac-address
          |  |  |  +---w mac-address    yang:mac-address
          |  |  +---w ipv4-address
          |  |  |  +---w ipv4-address    inet:ipv4-address
          |  |  +---w ipv6-address
          |  |  |  +---w ipv6-address    inet:ipv6-address
          |  |  +---w tp-attribute
          |  |  |  +---w tp-attribute-type?
          |  |  |  |       address-attribute-type
          |  |  |  +---w (tp-attribute-value)?
          |  |  |     +--:(ip-prefix)
          |  |  |     |  +---w ip-prefix?
          |  |  |     |          inet:ip-prefix
          |  |  |     +--:(bgp)
          |  |  |     |  +---w bgp?
          |  |  |     |          inet:ip-prefix
          |  |  |     +--:(tunnel)
          |  |  |     |  +---w tunnel-interface?         uint32
          |  |  |     +--:(pw)
          |  |  |     |  +---w remote-pe-address?
          |  |  |     |  |       inet:ip-address
          |  |  |     |  +---w pw-id?                    uint32
          |  |  |     +--:(vpls)
          |  |  |     |  +---w route-distinguisher?
          |  |  |     |  |       rt:route-distinguisher
          |  |  |     |  +---w sender-ve-id?             uint16
          |  |  |     |  +---w receiver-ve-id?           uint16
          |  |  |     +--:(mpls-mldp)
          |  |  |        +---w (root-address)?
          |  |  |           +--:(ip-address)
          |  |  |           |  +---w source-address?
          |  |  |           |  |       inet:ip-address
          |  |  |           |  +---w group-ip-address?
          |  |  |           |          inet:ip-address
          |  |  |           +--:(vpn)
          |  |  |           |  +---w as-number?
          |  |  |           |          inet:as-number
          |  |  |           +--:(global-id)
          |  |  |              +---w lsp-id?             string
          |  |  +---w system-info
          |  |     +---w router-id?   rt:router-id
          |  +---w source-interface      if:interface-ref
          |  +---w outbound-interface    if:interface-ref
          |  +---w vrf?
          |  |       cl-oam:routing-instance-ref
          |  +---w session-type?         enumeration
          |  +---w max-ttl?              uint8
          +--ro output
             +--ro response-list* [response-index]
             |  +--ro response-index           uint32
             |  +--ro protocol-id              identityref
             |  +--ro protocol-id-meta-data?   identityref
             |  +--ro status-code              identityref
             |  +--ro status-sub-code          identityref
             +--ro src-test-point
             |  +--ro ni?                 routing-instance-ref
             |  +--ro tp-location-type    identityref
             |  +--ro mac-address
             |  |  +--ro mac-address    yang:mac-address
             |  +--ro ipv4-address
             |  |  +--ro ipv4-address    inet:ipv4-address
             |  +--ro ipv6-address
             |  |  +--ro ipv6-address    inet:ipv6-address
             |  +--ro tp-attribute
             |  |  +--ro tp-attribute-type?
             |  |  |       address-attribute-type
             |  |  +--ro (tp-attribute-value)?
             |  |     +--:(ip-prefix)
             |  |     |  +--ro ip-prefix?
             |  |     |          inet:ip-prefix
             |  |     +--:(bgp)
             |  |     |  +--ro bgp?
             |  |     |          inet:ip-prefix
             |  |     +--:(tunnel)

4. OAM Retrieval Methods YANG Module ✨

okay so this part is where the data model gets real πŸ’… the diagram below is the rest of the Data Hierarchy of OAM Retrieval Methods (the tree we started back in Section 3.2), and then we get to the actual YANG module. it's giving blueprint energy πŸ¦‹

             |  |     |  +--ro tunnel-interface?         uint32
             |  |     +--:(pw)
             |  |     |  +--ro remote-pe-address?
             |  |     |  |       inet:ip-address
             |  |     |  +--ro pw-id?                    uint32
             |  |     +--:(vpls)
             |  |     |  +--ro route-distinguisher?
             |  |     |  |       rt:route-distinguisher
             |  |     |  +--ro sender-ve-id?             uint16
             |  |     |  +--ro receiver-ve-id?           uint16
             |  |     +--:(mpls-mldp)
             |  |        +--ro (root-address)?
             |  |           +--:(ip-address)
             |  |           |  +--ro source-address?
             |  |           |  |       inet:ip-address
             |  |           |  +--ro group-ip-address?
             |  |           |          inet:ip-address
             |  |           +--:(vpn)
             |  |           |  +--ro as-number?
             |  |           |          inet:as-number
             |  |           +--:(global-id)
             |  |              +--ro lsp-id?             string
             |  +--ro system-info
             |     +--ro router-id?   rt:router-id
             +--ro dest-test-point
             |  +--ro ni?                 routing-instance-ref
             |  +--ro tp-location-type    identityref
             |  +--ro mac-address
             |  |  +--ro mac-address    yang:mac-address
             |  +--ro ipv4-address
             |  |  +--ro ipv4-address    inet:ipv4-address
             |  +--ro ipv6-address
             |  |  +--ro ipv6-address    inet:ipv6-address
             |  +--ro tp-attribute
             |  |  +--ro tp-attribute-type?
             |  |  |       address-attribute-type
             |  |  +--ro (tp-attribute-value)?
             |  |     +--:(ip-prefix)
             |  |     |  +--ro ip-prefix?
             |  |     |          inet:ip-prefix
             |  |     +--:(bgp)
             |  |     |  +--ro bgp?
             |  |     |          inet:ip-prefix
             |  |     +--:(tunnel)
             |  |     |  +--ro tunnel-interface?         uint32
             |  |     +--:(pw)
             |  |     |  +--ro remote-pe-address?
             |  |     |  |       inet:ip-address
             |  |     |  +--ro pw-id?                    uint32
             |  |     +--:(vpls)
             |  |     |  +--ro route-distinguisher?
             |  |     |  |       rt:route-distinguisher
             |  |     |  +--ro sender-ve-id?             uint16
             |  |     |  +--ro receiver-ve-id?           uint16
             |  |     +--:(mpls-mldp)
             |  |        +--ro (root-address)?
             |  |           +--:(ip-address)
             |  |           |  +--ro source-address?
             |  |           |  |       inet:ip-address
             |  |           |  +--ro group-ip-address?
             |  |           |          inet:ip-address
             |  |           +--:(vpn)
             |  |           |  +--ro as-number?
             |  |           |          inet:as-number
             |  |           +--:(global-id)
             |  |              +--ro lsp-id?             string
             |  +--ro system-info
             |     +--ro router-id?   rt:router-id
             +--ro sequence-number?             uint64
             +--ro hop-cnt?                     uint8
             +--ro session-packet-statistics
             |  +--ro rx-packet-count?    uint32
             |  +--ro tx-packet-count?    uint32
             |  +--ro rx-bad-packet?      uint32
             |  +--ro tx-packet-failed?   uint32
             +--ro session-error-statistics
             |  +--ro packet-loss-count?          uint32
             |  +--ro loss-ratio?                 percentage
             |  +--ro packet-reorder-count?       uint32
             |  +--ro packets-out-of-seq-count?   uint32
             |  +--ro packets-dup-count?          uint32
             +--ro session-delay-statistics
             |  +--ro time-unit-value?       identityref
             |  +--ro min-delay-value?       uint32
             |  +--ro max-delay-value?       uint32
             |  +--ro average-delay-value?   uint32
             +--ro session-jitter-statistics
             |  +--ro unit-value?             identityref
             |  +--ro min-jitter-value?       uint32
             |  +--ro max-jitter-value?       uint32
             |  +--ro average-jitter-value?   uint32
             +--ro path-verification
             |  +--ro flow-info?
             |  |       string
             |  +--ro session-path-verification-statistics
             |     +--ro verified-count?   uint32
             |     +--ro failed-count?     uint32
             +--ro path-trace-info
                +--ro path-trace-info-list* [index]
                   +--ro index                   uint32
                   +--ro ni?
                   |       routing-instance-ref
                   +--ro tp-location-type        identityref
                   +--ro mac-address
                   |  +--ro mac-address    yang:mac-address
                   +--ro ipv4-address
                   |  +--ro ipv4-address    inet:ipv4-address
                   +--ro ipv6-address
                   |  +--ro ipv6-address    inet:ipv6-address
                   +--ro tp-attribute
                   |  +--ro tp-attribute-type?
                   |  |       address-attribute-type
                   |  +--ro (tp-attribute-value)?
                   |     +--:(ip-prefix)
                   |     |  +--ro ip-prefix?
                   |     |          inet:ip-prefix
                   |     +--:(bgp)
                   |     |  +--ro bgp?
                   |     |          inet:ip-prefix
                   |     +--:(tunnel)
                   |     |  +--ro tunnel-interface?
                   |     |          uint32
                   |     +--:(pw)
                   |     |  +--ro remote-pe-address?
                   |     |  |       inet:ip-address
                   |     |  +--ro pw-id?
                   |     |          uint32
                   |     +--:(vpls)
                   |     |  +--ro route-distinguisher?
                   |     |  |       rt:route-distinguisher
                   |     |  +--ro sender-ve-id?
                   |     |  |       uint16
                   |     |  +--ro receiver-ve-id?
                   |     |          uint16
                   |     +--:(mpls-mldp)
                   |        +--ro (root-address)?
                   |           +--:(ip-address)
                   |           |  +--ro source-address?
                   |           |  |       inet:ip-address
                   |           |  +--ro group-ip-address?
                   |           |          inet:ip-address
                   |           +--:(vpn)
                   |           |  +--ro as-number?
                   |           |          inet:as-number
                   |           +--:(global-id)
                   |              +--ro lsp-id?
                   |                      string
                   +--ro system-info
                   |  +--ro router-id?   rt:router-id
                   +--ro timestamp-type?         identityref
                   +--ro timestamp-64bit
                   |  +--ro timestamp-sec?       uint32
                   |  +--ro timestamp-nanosec?   uint32
                   +--ro timestamp-80bit {ptp-long-format}?
                   |  +--ro timestamp-sec?       uint64
                   |  +--ro timestamp-nanosec?   uint32
                   +--ro ntp-timestamp-32bit
                   |       {ntp-short-format}?
                   |  +--ro timestamp-sec?       uint16
                   |  +--ro timestamp-nanosec?   uint16
                   +--ro icmp-timestamp-32bit {icmp-timestamp}?
                   |  +--ro timestamp-millisec?   uint32
                   +--ro ingress-intf-name?
                   |       if:interface-ref
                   +--ro egress-intf-name?
                   |       if:interface-ref
                   +--ro queue-depth?            uint32
                   +--ro transit-delay?          uint32
                   +--ro app-meta-data?          uint64

Data Hierarchy of OAM Retrieval Methods

okay now the main event πŸŽ€ the YANG module itself. it's the actual machine-readable definition for the RPC operations, and the vibe is: the module is protocol-independent on purpose 🌈 every protocol maps the abstract stuff to its own native format, and protocols are free to extend the model with their own bits. iconic design, ngl 😭

   <CODE BEGINS> file
      "ietf-connectionless-oam-methods@2019-04-16.yang"

module ietf-connectionless-oam-methods {
  namespace
    "urn:ietf:params:xml:ns:yang:ietf-connectionless-oam-methods";
  prefix cloam-methods;

  import ietf-interfaces {
    prefix if;
  }
  import ietf-connectionless-oam {
    prefix cl-oam;
  }
  organization
    "IETF LIME Working Group";
  contact
    "WG Web:   <https://datatracker.ietf.org/wg/lime>
     WG List:  <mailto:lmap@ietf.org>

     Deepak Kumar <dekumar@cisco.com>
     Qin Wu <bill.wu@huawei.com>
     Srihari Raghavan <rihari@cisco.com>
     Michael Wang <wangzitao@huawei.com>
     Reshad Rahman <rrahman@cisco.com>";
  description
    "This YANG module defines the RPC operations for
     connectionless OAM to be used within the IETF
     in a protocol-independent manner.  It is
     assumed that each protocol maps corresponding
     abstracts to its native format.  Each protocol
     may extend the YANG data model defined here to
     include protocol-specific extensions.

     Copyright (c) 2019 IETF Trust and the persons identified as
     authors of the code.  All rights reserved.

     Redistribution and use in source and binary forms, with or
     without modification, is permitted pursuant to, and subject
     to the license terms contained in, the Simplified BSD License
     set forth in Section 4.c of the IETF Trust's Legal Provisions
     Relating to IETF Documents
     (http://trustee.ietf.org/license-info).

     This version of this YANG module is part of RFC 8533; see
     the RFC itself for full legal notices.";

  revision 2019-04-16 {
    description
      "Initial revision.";
    reference
      "RFC 8533: Retrieval Methods YANG Data Model for the Management
       of Operations, Administration, and Maintenance (OAM)
       Protocols That Use Connectionless Communications";
  }

  identity protocol-id {
    description
      "This is the base identity for a generic protocol
       ID.  The protocol registry can be found at
       https://www.iana.org/protocols.";
  }
  identity protocol-id-internet {
    base protocol-id;
    description
      "Identity for Internet Protocols.";
  }

  identity protocol-id-proprietary {
    base protocol-id;
    description
      "Identity for proprietary protocols (e.g.,
       IP SLA).";
  }

  identity protocol-id-sfc {
    base protocol-id;
    description
      "Identity for Service Function Chaining.";
  }

  identity protocol-id-mpls {
    base protocol-id;
    description
      "The MPLS protocol.";
  }

  identity protocol-id-mpls-tp {
    base protocol-id;
    description
      "The MPLS-TP protocol.";
  }

  identity protocol-id-twamp {
    base protocol-id;
    description
      "The Two-Way Active Measurement Protocol (TWAMP)
       protocol.";
  }

  identity protocol-id-bier {
    base protocol-id;
    description
      "The Bit Index Explicit Replication (BIER)
       protocol.";
  }

  identity status-code {
    description
      "This is base identity for a status code.";

  }

  identity success-reach {
    base status-code;
    description
      "Indicates that the destination being verified
       is reachable (see RFC 7276).";
    reference
      "RFC 7276: An Overview of Operations, Administration, and
       Maintenance (OAM) Tools";
  }

  identity fail-reach {
    base status-code;
    description
      "Indicates that the destination being verified
       is not reachable (see RFC 7276).";
    reference
      "RFC 7276: An Overview of Operations, Administration, and
       Maintenance (OAM) Tools";
  }
  identity success-path-verification {
    base status-code;
    description
      "Indicates that the path verification is performed
       successfully (see RFC 7276).";
    reference
      "RFC 7276: An Overview of Operations, Administration, and
       Maintenance (OAM) Tools";
  }

  identity fail-path-verification {
    base status-code;
    description
      "Indicates that the path verification fails
       (see RFC 7276).";
    reference
      "RFC 7276: An Overview of Operations, Administration, and
       Maintenance (OAM) Tools";
  }

  identity status-sub-code {
    description
      "IdentityBase status-sub-code.";
  }

  identity invalid-cc {

    base status-sub-code;
    description
      "Indicates that the Continuity Check message is invalid
       (see RFC 7276).";
    reference
      "RFC 7276: An Overview of Operations, Administration, and
       Maintenance (OAM) Tools";
  }

  identity invalid-pd {
    base status-sub-code;
    description
      "Indicates that the path discovery message is invalid
       (see RFC 7276).";
    reference
      "RFC 7276: An Overview of Operations, Administration, and
       Maintenance (OAM) Tools";
  }

  identity protocol-id-meta-data {
    description
      "This is the base identity for metadata that corresponds
       to the protocol ID.";
  }

  identity protocol-internet-number {
    base protocol-id-meta-data;
    description
      "Internet Protocol number for standard
       Internet Protocols (IANA-assigned Internet
       Protocol numbers) to help in protocol processing.
       The Protocol Numbers registry can be found at
       https://www.iana.org/assignments/protocol-numbers.";
  }

  grouping rpc-input-parameters {
    container destination-tp {
      uses cl-oam:tp-address;
      description
        "Destination test point.";
    }
    leaf source-interface {
      type if:interface-ref;
      mandatory true;
      description
        "Source interface.";
    }
    leaf outbound-interface {

      type if:interface-ref;
      mandatory true;
      description
        "Outbound interface.";
    }
    leaf vrf {
      type cl-oam:routing-instance-ref;
      description
        "Virtual Routing and Forwarding (VRF) instance.";
    }
    description
      "Grouping for RPC input parameters";
  }

  rpc continuity-check {
    if-feature "cl-oam:continuity-check";
    description
      "Continuity Check RPC operation as per RFC 7276.";
    reference
      "RFC 7276: An Overview of Operations, Administration, and
       Maintenance (OAM) Tools";
    input {
      uses rpc-input-parameters;
      uses cl-oam:session-type {
        description
          "If session-type is specified, then session-type
              must be set to on demand";
      }
      leaf count {
        type uint32 {
          range "0..4294967295" {
            description
              "The overall number of packets to be transmitted
               by the sender.  The value of the count will be set
               to zero (0) on creation and will thereafter
               increase monotonically until it reaches a maximum
               value of 2^32-1 (4294967295 decimal), when it wraps
               around and starts increasing again from zero.";
          }
        }
        default "5";
        description
          "Specifies the number of
           packets that will be sent.  By
           default, the packet number is
           set to 5.";
      }
      leaf ttl {

        type uint8;
        default "255";
        description
          "Time to live (TTL) used to limit the lifetime
           of data packets transmitted in the network
           to prevent looping.  The TTL value is decremented
           for every hop that the packet traverses.  If the
           TTL is zero, the data packet will be discarded.";
      }
      leaf packet-size {
        type uint32 {
          range "64..10000";
        }
        default "64";
        description
          "Packet size of the Continuity Check message, in octets.
           By default, the packet size is set to 64 octets.";
      }
    }
    output {
      container response-info {
        leaf protocol-id {
          type identityref {
            base protocol-id;
          }
          mandatory true;
          description
            "Protocol used in the Continuity Check message.
             This could be a standard protocol (e.g.,
             TCP/IP protocols, MPLS, etc.) or a proprietary
             protocol as identified by this field.";
        }
        leaf protocol-id-meta-data {
          type identityref {
            base protocol-id-meta-data;
          }
          description
            "An optional metadata related to the protocol ID.
             For example, this could be the Internet Protocol
             number for standard Internet Protocols used for
             help with protocol processing.";
        }
        leaf status-code {
          type identityref {
            base status-code;
          }
          mandatory true;
          description

            "Status code for Continuity Check RPC operation.
             This could be a basic status code (e.g., destination
             is reachable or destination is not reachable; see RFC 7276)
             or some customized status code as identified by this
             field.";
          reference
            "RFC 7276: An Overview of Operations, Administration, and
             Maintenance (OAM) Tools";
        }
        leaf status-sub-code {
          type identityref {
            base status-sub-code;
          }
          mandatory true;
          description
            "An optional status-sub-code for Continuity Check
             RPC operation.  If the basic status code is destination
             reachable, this status-sub-code doesn't need to be
             specified.  If the basic status code is destination
             unreachable, the status-sub-code can be used to specify
             the detailed reasons.  This could be a basic
             sub-status-code (such as an invalid Continuity Check) or
             other error codes specific to the protocol under use for
             the Continuity Checks.  For example, if ICMP is the
             protocol under use, the error codes defined in RFC 4443
             can be used to specify the reasons specific to ICMP.
             This technology-specific status-sub-code can be
             defined in technology-specific models.";
          reference
            "RFC 4443: The IETF Administrative Oversight Committee
             (IAOC) Member Selection Guidelines and Process.";
        }
        description
          "Status code and status-sub-code for Continuity Check RPC
           operation.";
      }
      uses cl-oam:continuity-check-data;
    }
  }

  rpc path-discovery {
    if-feature "cl-oam:path-discovery";
    description
      "Path discovery RPC operation as per RFC 7276.";
    reference
      "RFC 7276: An Overview of Operations, Administration, and
       Maintenance (OAM) Tools";
    input {

      uses rpc-input-parameters;
      uses cl-oam:session-type {
        description
          "If session-type is specified, then session-type
            must be set to on demand";
      }
      leaf max-ttl {
        type uint8;
        default "255";
        description
          "Maximum TTL indicates the maximum number of hops that
           a packet is permitted to travel before being discarded
           by a router.  By default, the maximum TTL is set to
           255.";
      }
    }
    output {
      list response-list {
        key "response-index";
        description
          "Path discovery response list.";
        leaf response-index {
          type uint32;
          mandatory true;
          description
            "Response index.";
        }
        leaf protocol-id {
          type identityref {
            base protocol-id;
          }
          mandatory true;
          description
            "Protocol used in path discovery.  This could be a
             standard protocol (e.g., TCP/IP protocols, MPLS, etc.)
             or a proprietary protocol as identified by
             this field.";
        }
        leaf protocol-id-meta-data {
          type identityref {
            base protocol-id-meta-data;
          }
          description
            "An optional metadata related to the protocol ID.
             For example, this could be the Internet Protocol
             number for standard Internet Protocols used for
             help with protocol processing.";
        }
        leaf status-code {
          type identityref {
            base status-code;
          }
          mandatory true;
          description
            "Status code for Continuity Check RPC operation.
             This could be a basic status code (e.g., destination
             is reachable or destination is not reachable) or some
             customized status code as identified by this field.";
        }
        leaf status-sub-code {
          type identityref {
            base status-sub-code;
          }
          mandatory true;
          description
            "An optional status-sub-code for Continuity Check
             RPC operation.  If the basic status code is destination
             reachable, this status-sub-code doesn't need to be
             specified.  If the basic status code is destination
             unreachable, the status-sub-code can be used to specify
             the detailed reasons.  This could be a basic
             sub-status-code (such as an invalid Continuity Check) or
             other error codes specific to the protocol under use for
             Continuity Checks.  For example, if ICMP is the protocol
             under use, the error codes defined in RFC 4443
             can be used to specify the reasons specific to ICMP.
             This technology-specific status-sub-code can be defined
             in technology-specific models.";
          reference
            "RFC 4443: The IETF Administrative Oversight Committee
             (IAOC) Member Selection Guidelines and Process.";
        }
      }
      uses cl-oam:path-discovery-data;
    }
  }
}

<CODE ENDS>

5. Security Considerations ✨

Okay bestie, security is serious business πŸ” so let's get into it. The YANG module in this document defines a schema for data that's meant to be accessed through network management protocols like NETCONF [RFC6241] or RESTCONF [RFC8040]. For NETCONF, the bottom layer is the secure transport layer, and the transport it has to support is Secure Shell (SSH) [RFC6242]. For RESTCONF, the bottom layer is HTTPS, and the transport it has to support is TLS [RFC8446]. πŸ™ˆ

Then there's the Network Configuration Access Control Model (NACM) [RFC8341], which is giving access control queen πŸ‘‘. It lets you restrict particular NETCONF or RESTCONF users to a preconfigured subset of all the available protocol operations and content, so not everyone gets to touch everything.

Some of the RPC operations in this YANG module may be considered sensitive or vulnerable in some network environments, so it's important to control access to them. Here are the operations and why they're sensitive πŸ’€:

  • continuity-check: Generates Continuity Check.
  • path-discovery: Generates path discovery.

These operations are used to retrieve data from the device that needs to execute the OAM command. Unauthorized source access to some of that sensitive information may be used for network reconnaissance, or it could lead to denial-of-service attacks on both the local device and the network. Honestly, that's a whole lot of drama, so lock it down πŸ”’πŸ’–

6. IANA Considerations πŸ’…

okay bestie, IANA gets two registrations from this doc πŸŽ€ First, a URI goes into the "IETF XML Registry" [RFC3688]. Here's the entry:

URI: urn:ietf:params:xml:ns:yang:ietf-connectionless-oam-methods
Registrant Contact: The IESG.  XML: N/A, the requested URI is an XML
namespace.

Second, a YANG module gets registered in the "YANG Module Names" registry [RFC6020] 🧚

name: ietf-connectionless-oam-methods
namespace:
   urn:ietf:params:xml:ns:yang:ietf-connectionless-oam-methods
prefix: cloam-methods
reference: RFC 8533

7. References πŸ¦‹

7.1. Normative References

7.2. Informative References

Appendix A. Extending Connectionless OAM Method Module Example ✨

okay so this appendix is the "how would I extend this thing" moment 🌸 Here's the snippet that augments the "ietf-connectionless-oam-methods" YANG data model with ICMP ping attributes. It's giving main character energy πŸ‘‘

augment "/cloam-methods:continuity-check"
+"/cloam-methods:output"{
  container session-rtt-statistics{
   leaf min-rtt{
    type uint32;
description
"This minimum ping round-trip-time (RTT) received.";
   }
   leaf max-rtt{
    type uint32;
description
"This maximum ping RTT received.";
   }
   leaf avg-rtt{
    type uint32;
description
 "The current average ping RTT.";
   }
   description
   "This container presents the ping RTT statistics.";
  }
}

A.1. Example of New Retrieval Procedures Model πŸ¦‹

as we talked about in the Introduction section, new retrieval procedures can be defined to pull the same data that the base YANG data model for connectionless OAM protocols already describes. This appendix shows how that base model can be extended to support persistent data retrieval, not just the on-demand retrieval procedures from Section 3. The flow is: first you retrieve a persistent-id based on the destination test point location information, then you retrieve the export details based on that persistent-id πŸ’œ The export options outlined here for now are Internet Protocol Flow Information Export (IPFIX) [RFC7011] and YANG-Push [YANG-Push]. More export options can be added in the future 🌈

The YANG module "example-cl-oam-persistent-methods" below is just an illustration. It is not a real definition of an RPC operation model for persistent data retrieval πŸ™ˆ For the sake of brevity, this module doesn't follow all the guidelines in [RFC8407], so don't copy it as a template without checking πŸ’€

module example-cl-oam-persistent-methods {
  namespace "http://example.com/cl-oam-persistent-methods";
  prefix pcloam-methods;

  import ietf-interfaces {
    prefix if;
  }
  import ietf-connectionless-oam {
    prefix cl-oam;
  }
  import ietf-yang-types {
    prefix yang;
  }

  identity export-method {
    description
      "Base identity to represent a conceptual
       export-method.";
  }

  identity ipfix-export {
    base export-method;
    description
      "IPFIX-based export.  Configuration provided
       separately.";
  }

  identity yang-push-export {
    base export-method;
    description
      "YANG-Push from draft-ietf-netconf-yang-push.";
  }

  identity protocol-id {
    description
      "A generic protocol identifier.";
  }

  identity status-code {
    description
      "Base status code.";
  }
  identity success-reach {
    base status-code;
    description
      "Indicates that the destination being verified
       is reachable.";
  }

  identity fail-reach {
    base status-code;
    description
      "Indicates that the destination being verified
       is not reachable";
  }

  identity success-path-verification {
    base status-code;
    description
      "Indicates that the path verification is performed
       successfully.";
  }

  identity fail-path-verification {
    base status-code;
    description
      "Indicates that the path verification fails.";
  }

  identity status-sub-code {
    description
      "Base status-sub-code.";
  }

  identity invalid-cc {
    base status-sub-code;
    description
      "Indicates that the Continuity Check message is
       invalid.";
  }

  identity invalid-pd {
    base status-sub-code;
    description
      "Indicates that the path discovery message is invalid.";
  }

  typedef export-method {
    type identityref {
      base export-method;

    }
    description
      "Export method type.";
  }

  typedef change-type {
    type enumeration {
      enum create {
        description
          "Change due to a create.";
      }
      enum delete {
        description
          "Change due to a delete.";
      }
      enum modify {
        description
          "Change due to an update.";
      }
    }
    description
      "Different types of changes that may occur.";
  }

  rpc cc-get-persistent-id {
    if-feature "cl-oam:continuity-check";
    description
      "Obtains Continuity Check persistent identification
       given mapping parameters as input.";
    input {
      container destination-tp {
        uses cl-oam:tp-address;
        description
          "Destination test point.";
      }
      uses cl-oam:session-type;
      leaf source-interface {
        type if:interface-ref;
        description
          "Source interface.";
      }
      leaf outbound-interface {
        type if:interface-ref;
        description
          "Outbound interface.";
      }
      leaf vrf {
        type cl-oam:routing-instance-ref;
        description
          "VRF instance.";
      }
    }
    output {
      container error-code {
        leaf protocol-id {
          type identityref {
            base protocol-id;
          }
          mandatory true;
          description
            "Protocol used.  This could be a standard
             protocol (e.g., TCP/IP protocols, MPLS, etc.)
             or a proprietary protocol as identified by
             this field.";
        }
        leaf protocol-id-meta-data {
          type uint64;
          description
            "An optional metadata related to the protocol ID.
             For example, this could be the Internet Protocol
             number for standard Internet Protocols used for
             help with protocol processing.";
        }
        leaf status-code {
          type identityref {
            base status-code;
          }
          mandatory true;
          description
            "Status code.";
        }
        leaf status-sub-code {
          type identityref {
            base status-sub-code;
          }
          mandatory true;
          description
            "Sub code for the Continuity Check.";
        }
        description
          "Status code and sub code.";
      }
      leaf cc-persistent-id {
        type string;
        description
          "Id to act as a cookie.";

      }
    }
  }
  rpc cc-persistent-get-export-details {
    if-feature "cl-oam:continuity-check";
    description
      "Given the persistent ID, gets the configuration
       options and details related to the configured data
       export.";
    input {
      leaf cc-persistent-id {
        type string;
        description
          "Persistent ID for use as a key in search.";
      }
    }
    output {
      container error-code {
        leaf protocol-id {
          type identityref {
            base protocol-id;
          }
          mandatory true;
          description
            "Protocol used.  This could be a standard
             protocol (e.g., TCP/IP protocols, MPLS, etc.)
             or a proprietary protocol as identified by
             this field.";
        }
        leaf protocol-id-meta-data {
          type uint64;
          description
            "An optional metadata related to the protocol ID.
             For example, this could be the Internet Protocol
             number for standard Internet Protocols used for
             help with protocol processing.";
        }
        leaf status-code {
          type identityref {
            base status-code;
          }
          mandatory true;
          description
            "Status code.";
        }
        leaf status-sub-code {
          type identityref {

            base status-sub-code;
          }
          mandatory true;
          description
            "Sub code for the Continuity Check.";
        }
        description
          "Status code and sub code.";
      }
      leaf data-export-method {
        type export-method;
        description
          "Type of export in use.";
      }
      choice cc-trigger {
        description
          "Necessary conditions for
           periodic or on-change trigger.";
        case periodic {
          description
            "Periodic reports.";
          leaf period {
            type yang:timeticks;
            description
              "Time interval between reports.";
          }
          leaf start-time {
            type yang:date-and-time;
            description
              "Timestamp from which reports were started.";
          }
        }
        case on-change {
          description
            "On-change trigger and not periodic.";
          leaf all-data-on-start {
            type boolean;
            description
              "Full update done on start or not.";
          }
          leaf-list excluded-change {
            type change-type;
            description
              "Changes that will not trigger an update.";
          }
        }
      }
    }

  }

  rpc pd-get-persistent-id {
    if-feature "cl-oam:path-discovery";
    description
      "Obtains persistent path discovery identification.";
    input {
      container destination-tp {
        uses cl-oam:tp-address;
        description
          "Destination test point.";
      }
      uses cl-oam:session-type;
      leaf source-interface {
        type if:interface-ref;
        description
          "Source interface.";
      }
      leaf outbound-interface {
        type if:interface-ref;
        description
          "Outbound interface.";
      }
      leaf vrf {
        type cl-oam:routing-instance-ref;
        description
          "VRF";
      }
    }
    output {
      list response-list {
        key "response-index";
        description
          "Path discovery response list.";
        leaf response-index {
          type uint32;
          mandatory true;
          description
            "Response index.";
        }
        leaf protocol-id {
          type identityref {
            base protocol-id;
          }
          mandatory true;
          description
            "Protocol used.  This could be a standard
             protocol (e.g., TCP/IP protocols, MPLS, etc.)
             or a proprietary protocol as identified by
             this field.";
        }
        leaf protocol-id-meta-data {
          type uint64;
          description
            "An optional metadata related to the protocol ID.
             For example, this could be the Internet Protocol
             number for standard Internet Protocols used for
             help with protocol processing.";
        }
        leaf status-code {
          type identityref {
            base status-code;
          }
          mandatory true;
          description
            "Status code for persistent path discovery
             information.";
        }
        leaf status-sub-code {
          type identityref {
            base status-sub-code;
          }
          mandatory true;
          description
            "Sub code for persistent path discovery
             information.";
        }
        leaf pd-persistent-id {
          type string;
          description
            "Id to act as a cookie.";
        }
      }
    }
  }

  rpc pd-persistent-get-export-details {
    if-feature "cl-oam:path-discovery";
    description
      "Given the persistent ID, gets the configuration
       options and details related to the configured data
       export.";
    input {
      leaf cc-persistent-id {
        type string;
        description

          "Persistent ID for use as a key in search.";
      }
    }
    output {
      list response-list {
        key "response-index";
        description
          "Path discovery response list.";
        leaf response-index {
          type uint32;
          mandatory true;
          description
            "Response index.";
        }
        leaf protocol-id {
          type identityref {
            base protocol-id;
          }
          mandatory true;
          description
            "Protocol used.  This could be a standard
             protocol (e.g., TCP/IP protocols, MPLS, etc.)
             or a proprietary protocol as identified by
             this field.";
        }
        leaf protocol-id-meta-data {
          type uint64;
          description
            "An optional metadata related to the protocol ID.
             For example, this could be the Internet Protocol
             number for standard Internet Protocols used for
             help with protocol processing.";
        }
        leaf status-code {
          type identityref {
            base status-code;
          }
          mandatory true;
          description
            "Status code for persistent path discovery
             creation.";
        }
        leaf status-sub-code {
          type identityref {
            base status-sub-code;
          }
          mandatory true;
          description

            "Sub code for persistent path discovery
             creation.";
        }
        leaf data-export-method {
          type export-method;
          description
            "Type of export.";
        }
        choice pd-trigger {
          description
            "Necessary conditions
             for periodic or on-change
             trigger.";
          case periodic {
            description
              "Periodic reports.";
            leaf period {
              type yang:timeticks;
              description
                "Time interval between reports.";
            }
            leaf start-time {
              type yang:date-and-time;
              description
                "Timestamp from which reports are started.";
            }
          }
          case on-change {
            description
              "On-change trigger and not periodic.";
            leaf all-data-on-start {
              type boolean;
              description
                "Full update done on start or not.";
            }
            leaf-list excluded-change {
              type change-type;
              description
                "Changes that will not trigger an update.";
            }
          }
        }
      }
    }
  }
}

Acknowledgements ✨

Huge thank-you 🫢 to the whole squad who reviewed this doc: Elwyn Davies, Alia Atlas, Brian E. Carpenter, Greg Mirsky, Adam Roach, Alissa Cooper, Eric Rescorla, Ben Campbell, Benoit Claise, Kathleen Moriarty, Carlos Pignataro, Benjamin Kaduk, and everyone else who helped out. Your deep reviews, comments, and proposals made the document so much better πŸ’–

Authors' Addresses πŸŽ€

Meet the authors πŸ’…

Deepak Kumar
CISCO Systems
510 McCarthy Blvd.
Milpitas, CA  95035
United States of America

Email: dekumar@cisco.com
Michael Wang
Huawei Technologies, Co., Ltd
101 Software Avenue, Yuhua District
Nanjing  210012
China

Email: wangzitao@huawei.com
Qin Wu (editor)
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu  210012
China

Email: bill.wu@huawei.com
Reshad Rahman
CISCO Systems
2000 Innovation Drive
Kanata, Ontario  K2K 3E8
Canada

Email: rrahman@cisco.com
Srihari Raghavan
CISCO Systems
Tril Infopark Sez, Ramanujan IT City
Neville Block, 2nd floor, Old Mahabalipuram Road
Chennai, Tamil Nadu  600113
India

Email: srihari@cisco.com
πŸ“¦ where this page comes from