Internet-Draft STAMP Data Model July 2021
Mirsky, et al. Expires 13 January 2022 [Page]
Workgroup:
Network Working Group
Internet-Draft:
draft-ietf-ippm-stamp-yang-09
Published:
Intended Status:
Standards Track
Expires:
Authors:
G. Mirsky
ZTE Corp.
X. Min
ZTE Corp.
W.S. Luo
Ericsson

Simple Two-way Active Measurement Protocol (STAMP) Data Model

Abstract

This document specifies the data model for implementations of Session-Sender and Session-Reflector for Simple Two-way Active Measurement Protocol (STAMP) mode using YANG.

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 13 January 2022.

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Table of Contents

1. Introduction

The Simple Two-way Active Measurement Protocol (STAMP) [RFC8762] can be used to measure performance parameters of IP networks such as latency, jitter, and packet loss by sending test packets and monitoring their experience in the network. The STAMP protocol [RFC8762] in unauthenticated mode is on-wire compatible with TWAMP Light, discussed in Appendix I [RFC5357]. The TWAMP Light is known to have many implementations though no common management framework being defined, thus leaving some aspects of test packet processing to interpretation. As one of the goals of STAMP is to support these variations, this document presents their analysis; describes the data model of the base STAMP specification. The defined STAMP data model can be augmented to include STAMP extensions, for example, described in [RFC8972]. This document defines the STAMP data model and specifies it formally, using the YANG data modeling language [RFC7950].

This version of the interfaces data model conforms to the Network Management Datastore Architecture (NMDA) defined in [RFC8342].

1.1. Conventions used in this document

1.1.1. 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. Scope, Model, and Applicability

The scope of this document includes a model of the STAMP as defined in [RFC8762] and Section 3 [RFC8972].


      o----------------------------------------------------------o
      |                        Config client                     |
      o----------------------------------------------------------o
            ||                                          ||
            ||             NETCONF/RESTCONF             ||
            ||                                          ||
  o----------------------o                o-------------------------o
  |    Config server     |                |      Config server      |
  |                      |                |                         |
  +----------------------+                +-------------------------+
  | STAMP Session-Sender | <--- STAMP---> | STAMP Session-Reflector |
  +----------------------+                +-------------------------+
Figure 1: STAMP Reference Model

2.1. Data Model Parameters

This section describes containers within the STAMP data model.

2.1.1. STAMP-Sender

The stamp-session-sender container holds items that are related to the configuration of the stamp Session-Sender logical entity.

The stamp-session-sender-state container holds information about the state of the particular STAMP test session.

RPCs stamp-sender-start and stamp-sender-stop respectively start and stop the referenced session by the stamp-session-id of the STAMP.

2.1.1.1. Controls for Test Session and Performance Metric Calculation

The data model supports several scenarios for a STAMP Session-Sender to execute test sessions and calculate performance metrics:

  • The test mode in which the test packets are sent unbound in time as defined by the parameter 'interval' in the stamp-session-sender container frequency is referred to as continuous mode. Performance metrics in the continuous mode are calculated at a period defined by the parameter 'measurement-interval'.
  • The test mode that has a specific number of the test packets configured for the test session in the 'number-of-packets' parameter is referred to as a periodic mode. The STAMP-Sender MAY repeat the test session with the same parameters. The 'repeat' parameter defines the number of tests and the 'repeat-interval' - the interval between the consecutive tests. The performance metrics are calculated after each test session when the interval defined by the 'session-timeout' expires.

2.1.2. STAMP-Reflector

The stamp-session-reflector container holds items that are related to the configuration of the STAMP Session-Reflector logical entity.

The stamp-session-refl-state container holds Session-Reflector state data for the particular STAMP test session.

3. Data Model

Creating the STAMP data model presents several challenges, and among them is the identification of a test-session at Session-Reflector. A Session-Reflector MAY require only as little as the STAMP Session Identifier (SSID) and the source IP address in received STAMP-Test packet to spawn a new test session. More so, to test processing of Class-of-Service along the same route in Equal Cost Multi-Path environment Session-Sender may perform STAMP test sessions concurrently using the same source IP address, source UDP port number, destination IP address, and destination UDP port number. Thus the only parameter that can be used to differentiate these test sessions would be DSCP value. The DSCP field may get re-marked along the path, and without the use of Class of Service TLV (Section 4.4 [RFC8972]) that will go undetected, but by using SSID and the source IP address as a key, we can ensure that STAMP test packets that are considered as different test sessions follow the same path even in ECMP environments.

3.1. Tree Diagrams

This section presents a simplified graphical representation of the STAMP data model using a YANG tree diagram [RFC8340].


module: ietf-stamp
    +--rw stamp
    |  +--rw stamp-session-sender {session-sender}?
    |  |  +--rw sender-enable?   boolean
    |  |  +--rw sender-test-session* [stamp-session-id]
    |  |     +--rw test-session-enable?           boolean
    |  |     +--rw number-of-packets?             union
    |  |     +--rw interval?                      uint32
    |  |     +--rw session-timeout?               uint32
    |  |     +--rw measurement-interval?          uint32
    |  |     +--rw repeat?                        union
    |  |     +--rw repeat-interval?               uint32
    |  |     +--rw dscp-value?                    inet:dscp
    |  |     +--rw test-session-reflector-mode?   session-reflector-mode
    |  |     +--rw sender-ip                      inet:ip-address
    |  |     +--rw session-sender-udp-port  inet:port-number
    |  |     +--rw stamp-session-id                uint32
    |  |     +--rw session-reflector-ip             inet:ip-address
    |  |     +--rw session-reflector-udp-port?      inet:port-number
    |  |     +--rw sender-timestamp-format?       timestamp-format
    |  |     +--rw security! {stamp-security}?
    |  |     |  +--rw key-chain?   kc:key-chain-ref
    |  |     +--rw first-percentile?              percentile
    |  |     +--rw second-percentile?             percentile
    |  |     +--rw third-percentile?              percentile
    |  +--rw stamp-session-reflector {session-reflector}?
    |     +--rw reflector-enable?       boolean
    |     +--rw ref-wait?               uint32
    |     +--rw reflector-mode-state?   session-reflector-mode
    |     +--rw reflector-test-session* [stamp-session-id]
    |        +--rw stamp-session-id                    union
    |        +--rw dscp-handling-mode?           session-dscp-mode
    |        +--rw dscp-value?                   inet:dscp
    |        +--rw sender-ip?                    union
    |        +--rw sender-udp-port?              union
    |        +--rw reflector-ip?                 union
    |        +--rw reflector-udp-port?           inet:port-number
    |        +--rw reflector-timestamp-format?   timestamp-format
    |        +--rw security! {stamp-security}?
    |           +--rw key-chain?   kc:key-chain-ref
Figure 2: STAMP Configuration Tree Diagram 

module: ietf-stamp
    +--ro stamp-state
       +--ro stamp-session-sender-state {session-sender}?
       |  +--ro test-session-state* [stamp-session-id]
       |     +--ro stamp-session-id              uint32
       |     +--ro sender-session-state?   enumeration
       |     +--ro current-stats
       |     |  +--ro start-time                    yang:date-and-time
       |     |  +--ro interval?                     uint32
       |     |  +--ro duplicate-packets?            uint32
       |     |  +--ro reordered-packets?            uint32
       |     |  +--ro sender-timestamp-format?      timestamp-format
       |     |  +--ro reflector-timestamp-format?   timestamp-format
       |     |  +--ro dscp?                         inet:dscp
       |     |  +--ro two-way-delay
       |     |  |  +--ro delay
       |     |  |  |  +--ro min?   yang:gauge64
       |     |  |  |  +--ro max?   yang:gauge64
       |     |  |  |  +--ro avg?   yang:gauge64
       |     |  |  +--ro delay-variation
       |     |  |     +--ro min?   yang:gauge32
       |     |  |     +--ro max?   yang:gauge32
       |     |  |     +--ro avg?   yang:gauge32
       |     |  +--ro one-way-delay-far-end
       |     |  |  +--ro delay
       |     |  |  |  +--ro min?   yang:gauge64
       |     |  |  |  +--ro max?   yang:gauge64
       |     |  |  |  +--ro avg?   yang:gauge64
       |     |  |  +--ro delay-variation
       |     |  |     +--ro min?   yang:gauge32
       |     |  |     +--ro max?   yang:gauge32
       |     |  |     +--ro avg?   yang:gauge32
       |     |  +--ro one-way-delay-near-end
       |     |  |  +--ro delay
       |     |  |  |  +--ro min?   yang:gauge64
       |     |  |  |  +--ro max?   yang:gauge64
       |     |  |  |  +--ro avg?   yang:gauge64
       |     |  |  +--ro delay-variation
       |     |  |     +--ro min?   yang:gauge32
       |     |  |     +--ro max?   yang:gauge32
       |     |  |     +--ro avg?   yang:gauge32
       |     |  +--ro low-percentile
       |     |  |  +--ro delay-percentile
       |     |  |  |  +--ro rtt-delay?        yang:gauge64
       |     |  |  |  +--ro near-end-delay?   yang:gauge64
       |     |  |  |  +--ro far-end-delay?    yang:gauge64
       |     |  |  +--ro delay-variation-percentile
       |     |  |     +--ro rtt-delay-variation?        yang:gauge32
       |     |  |     +--ro near-end-delay-variation?   yang:gauge32
       |     |  |     +--ro far-end-delay-variation?    yang:gauge32
       |     |  +--ro mid-percentile
       |     |  |  +--ro delay-percentile
       |     |  |  |  +--ro rtt-delay?        yang:gauge64
       |     |  |  |  +--ro near-end-delay?   yang:gauge64
       |     |  |  |  +--ro far-end-delay?    yang:gauge64
       |     |  |  +--ro delay-variation-percentile
       |     |  |     +--ro rtt-delay-variation?        yang:gauge32
       |     |  |     +--ro near-end-delay-variation?   yang:gauge32
       |     |  |     +--ro far-end-delay-variation?    yang:gauge32
       |     |  +--ro high-percentile
       |     |  |  +--ro delay-percentile
       |     |  |  |  +--ro rtt-delay?        yang:gauge64
       |     |  |  |  +--ro near-end-delay?   yang:gauge64
       |     |  |  |  +--ro far-end-delay?    yang:gauge64
       |     |  |  +--ro delay-variation-percentile
       |     |  |     +--ro rtt-delay-variation?        yang:gauge32
       |     |  |     +--ro near-end-delay-variation?   yang:gauge32
       |     |  |     +--ro far-end-delay-variation?    yang:gauge32
       |     |  +--ro two-way-loss
       |     |  |  +--ro loss-count?         int32
       |     |  |  +--ro loss-ratio?         percentage
       |     |  |  +--ro loss-burst-max?     int32
       |     |  |  +--ro loss-burst-min?     int32
       |     |  |  +--ro loss-burst-count?   int32
       |     |  +--ro one-way-loss-far-end
       |     |  |  +--ro loss-count?         int32
       |     |  |  +--ro loss-ratio?         percentage
       |     |  |  +--ro loss-burst-max?     int32
       |     |  |  +--ro loss-burst-min?     int32
       |     |  |  +--ro loss-burst-count?   int32
       |     |  +--ro one-way-loss-near-end
       |     |  |  +--ro loss-count?         int32
       |     |  |  +--ro loss-ratio?         percentage
       |     |  |  +--ro loss-burst-max?     int32
       |     |  |  +--ro loss-burst-min?     int32
       |     |  |  +--ro loss-burst-count?   int32
       |     |  +--ro sender-ip                     inet:ip-address
       |     |  +--ro session-sender-udp-port       inet:port-number
       |     |  +--ro session-reflector-ip                  inet:ip-address
       |     |  +--ro session-reflector-udp-port?   inet:port-number
       |     |  +--ro sent-packets?                 uint32
       |     |  +--ro rcv-packets?                  uint32
       |     |  +--ro sent-packets-error?           uint32
       |     |  +--ro rcv-packets-error?            uint32
       |     |  +--ro last-sent-seq?                uint32
       |     |  +--ro last-rcv-seq?                 uint32
       |     +--ro history-stats* [stamp-session-id]
       |        +--ro stamp-session-id                    uint32
       |        +--ro end-time                      yang:date-and-time
       |        +--ro interval?                     uint32
       |        +--ro duplicate-packets?            uint32
       |        +--ro reordered-packets?            uint32
       |        +--ro sender-timestamp-format?      timestamp-format
       |        +--ro reflector-timestamp-format?   timestamp-format
       |        +--ro dscp?                         inet:dscp
       |        +--ro two-way-delay
       |        |  +--ro delay
       |        |  |  +--ro min?   yang:gauge64
       |        |  |  +--ro max?   yang:gauge64
       |        |  |  +--ro avg?   yang:gauge64
       |        |  +--ro delay-variation
       |        |     +--ro min?   yang:gauge32
       |        |     +--ro max?   yang:gauge32
       |        |     +--ro avg?   yang:gauge32
       |        +--ro one-way-delay-far-end
       |        |  +--ro delay
       |        |  |  +--ro min?   yang:gauge64
       |        |  |  +--ro max?   yang:gauge64
       |        |  |  +--ro avg?   yang:gauge64
       |        |  +--ro delay-variation
       |        |     +--ro min?   yang:gauge32
       |        |     +--ro max?   yang:gauge32
       |        |     +--ro avg?   yang:gauge32
       |        +--ro one-way-delay-near-end
       |        |  +--ro delay
       |        |  |  +--ro min?   yang:gauge64
       |        |  |  +--ro max?   yang:gauge64
       |        |  |  +--ro avg?   yang:gauge64
       |        |  +--ro delay-variation
       |        |     +--ro min?   yang:gauge32
       |        |     +--ro max?   yang:gauge32
       |        |     +--ro avg?   yang:gauge32
       |        +--ro low-percentile
       |        |  +--ro delay-percentile
       |        |  |  +--ro rtt-delay?        yang:gauge64
       |        |  |  +--ro near-end-delay?   yang:gauge64
       |        |  |  +--ro far-end-delay?    yang:gauge64
       |        |  +--ro delay-variation-percentile
       |        |     +--ro rtt-delay-variation?        yang:gauge32
       |        |     +--ro near-end-delay-variation?   yang:gauge32
       |        |     +--ro far-end-delay-variation?    yang:gauge32
       |        +--ro mid-percentile
       |        |  +--ro delay-percentile
       |        |  |  +--ro rtt-delay?        yang:gauge64
       |        |  |  +--ro near-end-delay?   yang:gauge64
       |        |  |  +--ro far-end-delay?    yang:gauge64
       |        |  +--ro delay-variation-percentile
       |        |     +--ro rtt-delay-variation?        yang:gauge32
       |        |     +--ro near-end-delay-variation?   yang:gauge32
       |        |     +--ro far-end-delay-variation?    yang:gauge32
       |        +--ro high-percentile
       |        |  +--ro delay-percentile
       |        |  |  +--ro rtt-delay?        yang:gauge64
       |        |  |  +--ro near-end-delay?   yang:gauge64
       |        |  |  +--ro far-end-delay?    yang:gauge64
       |        |  +--ro delay-variation-percentile
       |        |     +--ro rtt-delay-variation?        yang:gauge32
       |        |     +--ro near-end-delay-variation?   yang:gauge32
       |        |     +--ro far-end-delay-variation?    yang:gauge32
       |        +--ro two-way-loss
       |        |  +--ro loss-count?         int32
       |        |  +--ro loss-ratio?         percentage
       |        |  +--ro loss-burst-max?     int32
       |        |  +--ro loss-burst-min?     int32
       |        |  +--ro loss-burst-count?   int32
       |        +--ro one-way-loss-far-end
       |        |  +--ro loss-count?         int32
       |        |  +--ro loss-ratio?         percentage
       |        |  +--ro loss-burst-max?     int32
       |        |  +--ro loss-burst-min?     int32
       |        |  +--ro loss-burst-count?   int32
       |        +--ro one-way-loss-near-end
       |        |  +--ro loss-count?         int32
       |        |  +--ro loss-ratio?         percentage
       |        |  +--ro loss-burst-max?     int32
       |        |  +--ro loss-burst-min?     int32
       |        |  +--ro loss-burst-count?   int32
       |        +--ro sender-ip                     inet:ip-address
       |        +--ro session-sender-udp-port       inet:port-number
       |        +--ro session-reflector-ip                  inet:ip-address
       |        +--ro session-reflector-udp-port?   inet:port-number
       |        +--ro sent-packets?                 uint32
       |        +--ro rcv-packets?                  uint32
       |        +--ro sent-packets-error?           uint32
       |        +--ro rcv-packets-error?            uint32
       |        +--ro last-sent-seq?                uint32
       |        +--ro last-rcv-seq?                 uint32
       +--ro stamp-session-refl-state {session-reflector}?
          +--ro reflector-light-admin-status?   boolean
          +--ro test-session-state* [stamp-session-id]
             +--ro stamp-session-id                    uint32
             +--ro reflector-timestamp-format?   timestamp-format
             +--ro sender-ip                     inet:ip-address
             +--ro session-sender-udp-port       inet:port-number
             +--ro session-reflector-ip                  inet:ip-address
             +--ro session-reflector-udp-port?   inet:port-number
             +--ro sent-packets?                 uint32
             +--ro rcv-packets?                  uint32
             +--ro sent-packets-error?           uint32
             +--ro rcv-packets-error?            uint32
             +--ro last-sent-seq?                uint32
             +--ro last-rcv-seq?                 uint32
Figure 3: STAMP State Tree Diagram 

  rpcs:
    +---x stamp-sender-start
    |  +---w input
    |     +---w stamp-session-id    uint32
    +---x stamp-sender-stop
       +---w input
          +---w stamp-stamp-session-id    uint32
Figure 4: STAMP RPC Tree Diagram

3.2. YANG Module 

<CODE BEGINS> file "ietf-stamp@2021-07-12.yang"


module ietf-stamp {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-stamp";
  //namespace need to be assigned by IANA
  prefix "ietf-stamp";

import ietf-inet-types {
prefix inet;
reference "RFC 6991: Common YANG Types.";
}
import ietf-yang-types {
     prefix yang;
reference "RFC 6991: Common YANG Types.";
}
import ietf-key-chain {
prefix kc;
reference "RFC 8177: YANG Data Model for Key Chains.";
}

  organization
    "IETF IPPM (IP Performance Metrics) Working Group";

  contact
    "WG Web: http://tools.ietf.org/wg/ippm/
     WG List: ippm@ietf.org

     Editor: Greg Mirsky
          gregimirsky@gmail.com
     Editor: Xiao Min
          xiao.min2@zte.com.cn
     Editor: Wei S Luo
          wei.s.luo@ericsson.com";

  description
    "This YANG module specifies a vendor-independent model
     for the Simple Two-way Active Measurement Protocol (STAMP).

     The data model covers two STAMP logical entities -
     Session-Sender and Session-Reflector; characteristics
     of the STAMP test session, as well as measured and
     calculated performance metrics.

        Copyright (c) 2021 IETF Trust and the persons identified as
        the document authors.  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 XXXX; see
        the RFC itself for full legal notices.";

  revision "2021-07-10" {
    description
      "Initial Revision. Base STAMP specification is covered";
    reference
      "RFC XXXX: STAMP YANG Data Model.";
  }

/*
 * Typedefs
 */
typedef session-reflector-mode {
  type enumeration {
    enum stateful {
      description
        "When the Session-Reflector is stateful,
        i.e. is aware of STAMP-Test session state.";
      }
      enum stateless {
        description
          "When the Session-Reflector is stateless,
          i.e. is not aware of the state of
          STAMP-Test session.";
      }
    }
    description "State of the Session-Reflector";
    reference
      "RFC 8762 Simple Two-way Active
       Measurement Protocol (STAMP) Section 4.";
}

typedef session-dscp-mode {
  type enumeration {
    enum copy-received-value {
      description
        "Use DSCP value copied from received
        STAMP test packet of the test session.";
    }
    enum use-configured-value {
      description
        "Use DSCP value configured for this
        test session on the Session-Reflector.";
    }
  }
  description
    "DSCP handling mode by Session-Reflector.";
}

typedef timestamp-format {
  type enumeration {
    enum ntp-format {
      description
        "NTP 64 bit format of a timestamp";
    }
    enum ptp-format {
      description
        "PTPv2 truncated format of a timestamp";
    }
  }
  description
    "Timestamp format used by Session-Sender
    or Session-Reflector.";
  reference
    "RFC 8762 Simple Two-way Active
     Measurement Protocol (STAMP) Section 4.2.1.";
}

typedef percentage {
  type decimal64 {
    fraction-digits 5;
  }
  description "Percentage";
}

typedef percentile {
  type decimal64 {
    fraction-digits 5;
  }
  description
    "Percentile is a measure used in statistics
    indicating the value below which a given
    percentage of observations in a group of
    observations fall.";
}


/*
 * Feature definitions.
 */
feature session-sender {
  description
    "This feature relates to the device functions as the
    STAMP Session-Sender";
  reference
    "RFC 8762 Simple Two-way Active
     Measurement Protocol (STAMP) Section 4.2.";
}

feature session-reflector {
  description
    "This feature relates to the device functions as the
    STAMP Session-Reflector";
  reference
    "RFC 8762 Simple Two-way Active
     Measurement Protocol (STAMP) Section 4.3.";
}

feature stamp-security {
  description "Secure STAMP supported";
  reference
   "RFC 8762 Simple Two-way Active
     Measurement Protocol (STAMP) Section 4.4.";
}

/*
 * Reusable node groups
 */

grouping maintenance-statistics {
  description "Maintenance statistics grouping";
  leaf sent-packets {
    type uint32;
    description "Packets sent";
  }
  leaf rcv-packets {
    type uint32;
    description "Packets received";
  }
  leaf sent-packets-error {
    type uint32;
    description "Packets sent error";
  }
  leaf rcv-packets-error {
    type uint32;
    description "Packets received error";
  }
  leaf last-sent-seq {
    type uint32;
    description "Last sent sequence number";
  }
  leaf last-rcv-seq {
    type uint32;
    description "Last received sequence number";
  }
}

grouping test-session-statistics {
  description
    "Performance metrics calculated for
    a STAMP test session.";

  leaf interval  {
    type uint32;
    units microseconds;
    description
            "Time interval between transmission of two
      consecutive packets in the test session";
    }

    leaf duplicate-packets  {
      type uint32;
      description "Duplicate packets";
    }

    leaf reordered-packets  {
      type uint32;
      description "Reordered packets";
    }

    leaf sender-timestamp-format {
      type timestamp-format;
      description "Sender Timestamp format";
    }

    leaf reflector-timestamp-format {
      type timestamp-format;
      description "Reflector Timestamp format";
    }

    leaf dscp {
      type inet:dscp;
      description
        "The DSCP value that was placed in the header of
         STAMP UDP test packets by the Session-Sender.";
    }

    container two-way-delay {
      description
        "two way delay result of the test session";
      uses delay-statistics;
    }

    container one-way-delay-far-end {
      description
        "one way delay far-end of the test session";
      uses delay-statistics;
    }

    container one-way-delay-near-end {
      description
        "one way delay near-end of the test session";
      uses delay-statistics;
    }

    container low-percentile {
      when "/stamp/stamp-session-sender/"
        +"sender-test-session[stamp-session-id]/"
        +"first-percentile != '0.00'" {
          description
            "Only valid if the
            the first-percentile is not NULL";
      }
     description
      "Low percentile report";
       uses time-percentile-report;
    }

    container mid-percentile {
      when "/stamp/stamp-session-sender/"
        +"sender-test-session[stamp-session-id]/"
        +"second-percentile != '0.00'" {
          description
            "Only valid if the
            the first-percentile is not NULL";
      }
      description
      "Mid percentile report";
       uses time-percentile-report;
    }

    container high-percentile {
      when "/stamp/stamp-session-sender/"
        +"sender-test-session[stamp-session-id]/"
        +"third-percentile != '0.00'" {
        description
          "Only valid if the
           the first-percentile is not NULL";
      }
     description
        "High percentile report";
      uses time-percentile-report;
    }

    container two-way-loss {
      description
        "Two way loss count and ratio result of
        the test session";
      uses packet-loss-statistics;
    }

    container one-way-loss-far-end {
      when "/stamp/stamp-session-sender/"
        +"sender-test-session[stamp-session-id]/"
        +"test-session-reflector-mode = 'stateful'" {
        description
          "One-way statistic is only valid if the
          session-reflector is in stateful mode.";
      }
      description
        "One way loss count and ratio far-end of
         the test session";
      uses packet-loss-statistics;
    }

    container one-way-loss-near-end {
      when "/stamp/stamp-session-sender/"
        +"sender-test-session[stamp-session-id]/"
        +"test-session-reflector-mode = 'stateful'" {
        description
          "One-way statistic is only valid if the
           session-reflector is in stateful mode.";
      }
      description
        "One way loss count and ratio near-end of
        the test session";
      uses packet-loss-statistics;
    }
    uses session-parameters;
    uses maintenance-statistics;
}

grouping stamp-session-percentile {
  description "Percentile grouping";
  leaf first-percentile {
    type percentile;
    default 95.00;
    description
      "First percentile to report";
  }
  leaf second-percentile {
    type percentile;
    default 99.00;
    description
      "Second percentile to report";
  }
  leaf third-percentile {
    type percentile;
    default 99.90;
    description
      "Third percentile to report";
  }
}

grouping delay-statistics {
  description "Delay statistics grouping";
  container delay {
  description "Packets transmitted delay";
    leaf min {
      type yang:gauge64;
      units nanoseconds;
      description
        "Min of Packets transmitted delay";
    }
    leaf max {
      type yang:gauge64;
      units nanoseconds;
      description
        "Max of Packets transmitted delay";
    }
    leaf avg {
    type yang:gauge64;
    units nanoseconds;
    description
      "Avg of Packets transmitted delay";
    }
  }

  container delay-variation {
    description
      "Packets transmitted delay variation";
    leaf min {
      type yang:gauge32;
      units nanoseconds;
      description
        "Min of Packets transmitted
         delay variation";
    }
    leaf max {
      type yang:gauge32;
      units nanoseconds;
      description
        "Max of Packets transmitted
         delay variation";
    }
    leaf avg {
      type yang:gauge32;
      units nanoseconds;
                description
        "Avg of Packets transmitted
         delay variation";
    }
  }
}

grouping time-percentile-report {
  description "Delay percentile report grouping";
  container delay-percentile {
    description
      "Report round-trip, near- and far-end delay";
    leaf rtt-delay {
      type yang:gauge64;
      units nanoseconds;
      description
        "Percentile of round-trip delay";
    }
    leaf near-end-delay {
      type yang:gauge64;
        units nanoseconds;
        description
          "Percentile of near-end delay";
    }
    leaf far-end-delay {
      type yang:gauge64;
      units nanoseconds;
      description
        "Percentile of far-end delay";
    }
  }

  container delay-variation-percentile {
    description
      "Report round-trip, near- and far-end delay variation";
    leaf rtt-delay-variation {
      type yang:gauge32;
      units nanoseconds;
      description
        "Percentile of round-trip delay-variation";
    }
    leaf near-end-delay-variation {
      type yang:gauge32;
      units nanoseconds;
      description
        "Percentile of near-end delay variation";
    }
    leaf far-end-delay-variation {
      type yang:gauge32;
      units nanoseconds;
      description
        "Percentile of far-end delay-variation";
    }
  }
}

grouping packet-loss-statistics {
  description
    "Grouping for Packet Loss statistics";
  leaf loss-count {
    type int32;
    description
      "Number of lost packets
       during the test interval.";
  }
  leaf loss-ratio {
    type percentage;
    description
      "Ratio of packets lost to packets
       sent during the test interval.";
  }
  leaf loss-burst-max {
    type int32;
    description
      "Maximum number of consecutively
       lost packets during the test interval.";
  }
  leaf loss-burst-min {
    type int32;
    description
      "Minimum number of consecutively
       lost packets during the test interval.";
  }
  leaf loss-burst-count {
    type int32;
    description
    "Number of occasions with packet
     loss during the test interval.";
  }
}

grouping session-parameters {
  description
    "Parameters Session-Sender";
  leaf sender-ip {
    type inet:ip-address;
    mandatory true;
    description "Sender IP address";
  }
  leaf session-sender-udp-port {
    type inet:port-number {
      range "49152..65535";
    }
    mandatory true;
    description "Sender UDP port number";
    reference
    "RFC 8762 Simple Two-Way Active
     Measurement Protocol Section 4.1.";
  }
  leaf stamp-session-id {
    type uint32;
    description
    "A STAMP test session identifier
    assigned by the Session-Sender.";
    reference
    "RFC 8972 Simple Two-Way Active
     Measurement Protocol Optional
     Extensions Section 3.";
  }
  leaf session-reflector-ip {
    type inet:ip-address;
    mandatory true;
    description "Reflector IP address";
  }
  leaf session-reflector-udp-port {
    type inet:port-number{
      range "862 | 1024..49151 | 49152..65535";
    }
    default 862;
    description
    "Reflector UDP port number";
    reference
    "RFC 8762 Simple Two-Way Active
     Measurement Protocol Section 4.1.";
  }
}

grouping session-security {
  description
    "Grouping for STAMP security and related parameters";
  container security {
    if-feature stamp-security;
    presence "Enables secure STAMP";
    description
      "Parameters for STAMP authentication";
    leaf key-chain {
      type kc:key-chain-ref;
      description "Name of key-chain";
    }
  }
  reference
    "RFC 8762 Simple Two-Way Active
     Measurement Protocol Section 4.4.";
}

/*
 * Configuration Data
 */
container stamp {
  description
    "Top level container for STAMP configuration";

  container stamp-session-sender {
    if-feature session-sender;
    description "STAMP Session-Sender container";

    leaf sender-enable {
      type boolean;
      default "true";
      description
        "Whether this network element is enabled to
        act as STAMP Session-Sender";
      reference
        "RFC 8762 Simple Two-Way Active
         Measurement Protocol Section 4.2.";
    }

    list sender-test-session {
      key "stamp-session-id";
      unique "stamp-session-id";
      description
        "This structure is a container of test session
        managed objects";

      leaf test-session-enable {
        type boolean;
        default "true";
        description
          "Whether this STAMP Test session is enabled";
      }

      leaf number-of-packets {
        type union {
          type uint32 {
            range 1..4294967294 {
            description
              "The overall number of UDP test packet
              to be transmitted by the sender for this
              test session";
            }
          }
          type enumeration {
            enum forever {
              description
                "Indicates that the test session SHALL
                be run *forever*.";
            }
          }
        }
        default 10;
        description
          "This value determines if the STAMP-Test session is
          bound by number of test packets or not.";
      }

      leaf interval  {
        type uint32;
        units microseconds;
        description
          "Time interval between transmission of two
          consecutive packets in the test session in
          microseconds";
      }

      leaf session-timeout {
        when "../number-of-packets != 'forever'" {
          description
            "Test session timeout only valid if the
            test mode is periodic.";
        }
        type uint32;
        units "seconds";
        default 900;
        description
          "The timeout value for the Session-Sender to
          collect outstanding reflected packets.";
      }

      leaf measurement-interval {
        when "../number-of-packets = 'forever'" {
          description
            "Valid only when the test to run forever,
            i.e. continuously.";
        }
        type uint32;
        units "seconds";
        default 60;
        description
          "Interval to calculate performance metric when
          the test mode is 'continuous'.";
      }

      leaf repeat {
        type union {
          type uint32 {
            range 0..4294967294;
          }
          type enumeration {
            enum forever {
              description
                "Indicates that the test session SHALL
                be repeated *forever* using the
                information in repeat-interval
                parameter, and SHALL NOT decrement
                the value.";
            }
          }
        }
        default 0;
        description
          "This value determines if the STAMP-Test session must
          be repeated. When a test session has completed, the
          repeat parameter is checked. The default value
          of 0 indicates that the session MUST NOT be repeated.
          If the repeat value is 1 through 4,294,967,294
          then the test session SHALL be repeated using the
          information in repeat-interval parameter.
          The implementation MUST decrement the value of repeat
          after determining a repeated session is expected.";
      }

      leaf repeat-interval {
        when "../repeat != '0'";
        type uint32;
        units seconds;
        default 0;
        description
          "This parameter determines the timing of repeated
          STAMP-Test sessions when repeat is more than 0.";
      }

      leaf dscp-value {
        type inet:dscp;
        default 0;
        description
          "DSCP value to be set in the test packet.";
      }

      leaf test-session-reflector-mode {
        type session-reflector-mode;
        default "stateless";
        description
          "The mode of STAMP-Reflector for the test session.";
      }

      uses session-parameters;
      leaf sender-timestamp-format {
        type timestamp-format;
        default ntp-format;
        description "Sender Timestamp format";
      }
      uses session-security;
      uses stamp-session-percentile;
    }
  }

  container stamp-session-reflector {
    if-feature session-reflector;
    description
      "STAMP Session-Reflector container";
    leaf reflector-enable {
      type boolean;
      default "true";
      description
        "Whether this network element is enabled to
        act as STAMP Session-Reflector";
    }

    leaf ref-wait {
      type uint32 {
        range 1..604800;
      }
      units seconds;
      default 900;
          description
        "REFWAIT(STAMP test session timeout in seconds),
        the default value is 900";
    }

    leaf reflector-mode-state {
      type session-reflector-mode;
            default stateless;
      description
        "The state of the mode of the STAMP
        Session-Reflector";
    }

    list reflector-test-session {
      key "session-index";
      unique "sender-ip stamp-session-id";
      description
        "This structure is a container of test session
        managed objects";

      leaf session-index {
        type uint32;
        description "Session index";
      }

      leaf stamp-session-id {
        type union {
          type uint32;
          type enumeration {
            enum any {
              description
                "Indicates that the Session-Reflector
                accepts STAMP test packets from
                a Session-Sender with any SSID
                value";
            }
          }
        }
        description
          "This value determines whether specific
          SSID of the Session-Sender
          or the wildcard, i.e. any SSID accepted";
        reference
          "RFC 8972 Simple Two-Way Active
          Measurement Protocol Optional
          Extensions Section 3.";
      }

      leaf dscp-handling-mode {
        type session-dscp-mode;
        default copy-received-value;
        description
          "Session-Reflector handling of DSCP:
          - use value copied from received STAMP-Test packet;
          - use value explicitly configured";
      }

      leaf dscp-value {
        when "../dscp-handling-mode = 'use-configured-value'";
        type inet:dscp;
        default 0;
        description
        "DSCP value to be set in the reflected packet
        if dscp-handling-mode is set to use-configured-value.";
      }

      leaf sender-ip {
        type union {
          type inet:ip-address;
          type enumeration {
            enum any {
              description
                "Indicates that the Session-Reflector
                accepts STAMP test packets from
                any Session-Sender";
            }
          }
        }
        default any;
        description
          "This value determines whether specific
          IPv4/IPv6 address of the Session-Sender
          or the wildcard, i.e. any address";
      }

      leaf sender-udp-port {
        type union {
          type inet:port-number {
            range "49152..65535";
          }
          type enumeration {
            enum any {
              description
                "Indicates that the Session-Reflector
                accepts STAMP test packets from
                any Session-Sender";
            }
          }
        }
        default any;
        description
          "This value determines whether specific
          port number of the Session-Sender
          or the wildcard, i.e. any";
      }

      leaf reflector-ip {
        type union {
          type inet:ip-address;
          type enumeration {
            enum any {
              description
                "Indicates that the Session-Reflector
                accepts STAMP test packets on
                any of its interfaces";
            }
          }
        }
        default any;
        description
          "This value determines whether specific
          IPv4/IPv6 address of the Session-Reflector
          or the wildcard, i.e. any address";
      }

      leaf reflector-udp-port {
        type inet:port-number{
          range "862 | 1024..49151 | 49152..65535";
        }
        default 862;
        description
        "Reflector UDP port number";
        reference
        "RFC 8762 Simple Two-Way Active
         Measurement Protocol Section 4.1.";
      }

      leaf reflector-timestamp-format {
        type timestamp-format;
        default ntp-format;
        description "Reflector Timestamp format";
      }
      uses session-security;
    }
  }
}

 /*
 * Operational state data nodes
 */
container stamp-state {
  config false;
  description
    "Top level container for STAMP state data";

  container stamp-session-sender-state {
    if-feature session-sender;
    description
      "Session-Sender container for state data";
    list test-session-state{
      key "session-index";
      description
        "This structure is a container of test session
        managed objects";

      leaf session-index {
        type uint32;
        description "Session index";
      }

      leaf sender-session-state {
        type enumeration {
          enum active {
            description "Test session is active";
          }
          enum ready {
            description "Test session is idle";
          }
        }
        description
          "State of the particular STAMP test
          session at the sender";
      }

      container current-stats {
        description
          "This container contains the results for the current
          Measurement Interval in a Measurement session ";
        leaf start-time {
          type yang:date-and-time;
          mandatory true;
          description
            "The time that the current Measurement Interval started";
        }

        uses test-session-statistics;

      }

      list history-stats {
        key session-index;
        description
          "This container contains the results for the history
          Measurement Interval in a Measurement session ";
        leaf session-index {
          type uint32;
          description
            "The identifier for the Measurement Interval
            within this session";
        }

        leaf end-time {
          type yang:date-and-time;
          mandatory true;
          description
            "The time that the Measurement Interval ended";
        }

        uses test-session-statistics;
      }
    }
  }

  container stamp-session-refl-state {
    if-feature session-reflector;
    description
      "STAMP Session-Reflector container for
      state data";
    leaf reflector-light-admin-status {
      type boolean;
      description
        "Whether this network element is enabled to
        act as STAMP Session-Reflector";
    }

    list test-session-state {
      key "session-index";
      description
        "This structure is a container of test session
        managed objects";

      leaf session-index {
        type uint32;
        description "Session index";
      }

      leaf reflector-timestamp-format {
        type timestamp-format;
        description "Reflector Timestamp format";
      }
      uses session-parameters;
      uses maintenance-statistics;

    }
  }
}

rpc stamp-sender-start {
  description
    "start the configured sender session";
  input {
    leaf stamp-session-id {
      type uint32;
      mandatory true;
      description
        "The STAMP session to be started";
    }
  }
}

rpc stamp-sender-stop {
  description
    "stop the configured sender session";
  input {
    leaf stamp-session-id {
      type uint32;
      mandatory true;
      description
        "The session to be stopped";
    }
  }
}
}


<CODE ENDS>

4. IANA Considerations

This document registers a URI in the IETF XML registry [RFC3688]. Following the format in [RFC3688], the following registration is requested to be made.

URI: urn:ietf:params:xml:ns:yang:ietf-stamp

Registrant Contact: The IPPM WG of the IETF.

XML: N/A, the requested URI is an XML namespace.

This document registers a YANG module in the YANG Module Names registry [RFC7950].

name: ietf-stamp

namespace: urn:ietf:params:xml:ns:yang:ietf-stamp

prefix: stamp

reference: RFC XXXX

5. Security Considerations

The YANG module specified in this document defines a schema for data that is designed to be accessed via network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC8446].

The NETCONF access control model [RFC8341] provides the means to restrict access for particular NETCONF or RESTCONF users to a pre-configured subset of all available NETCONF or RESTCONF protocol operations and content.

There are a number of data nodes defined in this YANG module that are writable/creatable/deletable (i.e., config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations (e.g., edit-config) to these data nodes without proper protection can have an adverse effect on network operations. These are the subtrees and data nodes and their sensitivity/vulnerability:

TBD

Unauthorized access to any data node of these subtrees can adversely affect the routing subsystem of both the local device and the network. This may lead to corruption of the measurement that may result in false corrective action, e.g., false negative or false positive. That could be, for example, prolonged and undetected deterioration of the quality of service or actions to improve the quality unwarranted by the real network conditions.

Some of the readable data nodes in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. These are the subtrees and data nodes and their sensitivity/vulnerability:

TBD

Unauthorized access to any data node of these subtrees can disclose the operational state information of VRRP on this device.

Some of the RPC operations in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control access to these operations. These are the operations and their sensitivity/vulnerability:

TBD

6. Acknowledgments

Authors recognize and appreciate valuable comments provided by Adrian Pan and Henrik Nydell.

7. References

7.1. Normative References

[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/info/rfc2119>.
[RFC3688]
Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, , <https://www.rfc-editor.org/info/rfc3688>.
[RFC5357]
Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J. Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)", RFC 5357, DOI 10.17487/RFC5357, , <https://www.rfc-editor.org/info/rfc5357>.
[RFC6241]
Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, , <https://www.rfc-editor.org/info/rfc6241>.
[RFC6242]
Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, , <https://www.rfc-editor.org/info/rfc6242>.
[RFC7950]
Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, , <https://www.rfc-editor.org/info/rfc7950>.
[RFC8040]
Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, , <https://www.rfc-editor.org/info/rfc8040>.
[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/info/rfc8174>.
[RFC8341]
Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, , <https://www.rfc-editor.org/info/rfc8341>.
[RFC8342]
Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., and R. Wilton, "Network Management Datastore Architecture (NMDA)", RFC 8342, DOI 10.17487/RFC8342, , <https://www.rfc-editor.org/info/rfc8342>.
[RFC8446]
Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, , <https://www.rfc-editor.org/info/rfc8446>.
[RFC8762]
Mirsky, G., Jun, G., Nydell, H., and R. Foote, "Simple Two-Way Active Measurement Protocol", RFC 8762, DOI 10.17487/RFC8762, , <https://www.rfc-editor.org/info/rfc8762>.
[RFC8972]
Mirsky, G., Min, X., Nydell, H., Foote, R., Masputra, A., and E. Ruffini, "Simple Two-Way Active Measurement Protocol Optional Extensions", RFC 8972, DOI 10.17487/RFC8972, , <https://www.rfc-editor.org/info/rfc8972>.

7.2. Informative References

[RFC8340]
Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, , <https://www.rfc-editor.org/info/rfc8340>.

Appendix A. Example of STAMP Session Configuration

Figure 5 shows a configuration example of a STAMP-Sender.

   <?xml version="1.0" encoding="utf-8"?>
   <data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
    <stamp xmlns="urn:ietf:params:xml:ns:yang:ietf-stamp">
        <stamp-session-sender>
          <session-enable>enable</session-enable>
            <stamp-session-id>10</stamp-session-id>
            <test-session-enable>enable<test-session-enable>
            <number-of-packets>forever</number-of-packets>
            <interval>10</interval> <!-- 10 microseconds -->
            <measurement-interval/> <!-- use default 60 seconds -->
            <!-- use default 0 repetitions,
                  i.e. do not repeat this session -->
            <repeat/>
            <dscp-value/> <!-- use deafult 0 (CS0) -->
            <!-- use default 'stateless' -->
            <test-session-reflector-mode/>
            <sender-ip></sender-ip>
            <session-sender-udp-port></session-sender-udp-port>
            <session-reflector-ip></session-reflector-ip>
            <session-reflector-udp-port/> <!-- use default 862 -->
            <sender-timestamp-format/>
            <!-- No authentication -->
            <first-percentile/> <!-- use default 95 -->
            <second-percentile/> <!-- use default 99 -->
            <third-percentile/> <!-- use default 99.9 -->
        </stamp-session-sender>
     </stamp>
   </data>
Figure 5: XML instance of STAMP Session-Sender configuration 
   <?xml version="1.0" encoding="utf-8"?>
   <data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
    <stamp xmlns="urn:ietf:params:xml:ns:yang:ietf-stamp">
        <stamp-session-reflector>
          <session-enable>enable</session-enable>
          <ref-wait/> <!-- use default 900 seconds -->
          <!-- use default 'stateless' -->
          <reflector-mode-state/>
          <stamp-session-id/>   <!-- use default 'any' -->
          <!-- use default 'copy-received-value' -->
          <dscp-handling-mode/>
          <!-- not used because of dscp-hanling-mode
                being 'copy-received-value' -->
          <dscp-value/>
          <sender-ip/> <!-- use default 'any' -->
          <sender-udp-port/>  <!-- use default 'any' -->
          <reflector-ip/> <!-- use default 'any' -->
          <reflector-udp-port/>  <!-- use default 862 -->
          <reflector-timestamp-format/>
          <!-- No authentication -->
        </stamp-session-reflector>
     </stamp>
   </data>
Figure 6: XML instance of STAMP Session-Reflector configuration

Authors' Addresses

Greg Mirsky
ZTE Corp.
Xiao Min
ZTE Corp.
Wei S Luo
Ericsson