Network Working Group G. Mirsky
Internet-Draft X. Min
Intended status: Standards Track ZTE Corp.
Expires: September 2, 2018 W. Luo
Ericsson
March 1, 2018

Simple Two-way Active Measurement Protocol (STAMP) Data Model
draft-ietf-ippm-stamp-yang-01

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/.

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This Internet-Draft will expire on September 2, 2018.

Copyright Notice

Copyright (c) 2018 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

The Simple Two-way Active Measurement Protocol (STAMP) [I-D.ietf-ippm-stamp] 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 [Editor:ref to STAMP draft] in unauthenticated mode is on-wire compatible with STAMP Light, discussed in Appendix I [RFC5357]. The STAMP 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 goals of STAMP is to support these variations, this document presents their analysis; describes common STAMP and STAMP model while allowing for STAMP extensions in the future. This document defines the STAMP data model and specifies it formally using the YANG data modeling language [RFC6020].

This version of the interfaces data model confirms to the Network Management Datastore Architecture (NMDA) defined in [I-D.ietf-netmod-revised-datastores].

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 model of the STAMP as defined in [Editor:ref to STAMP draft].

             
      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 all the parameters of the 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 by session-id STAMP test session.

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:

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 STAMP data model presents number of challenges and among them is identification of a test-session at Session-Reflector. A Session-Reflector MAY require only as little as its IP and UDP port number in received STAMP-Test packet to spawn 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 run 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 use of [RFC7750] that will go undetected, but by using five-tuple instead of four-tuple 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

          
module: ietf-stamp
    +--rw stamp
    |  +--rw stamp-session-sender {session-sender}?
    |  |  +--rw sender-enable?   enable
    |  |  +--rw test-session* [session-id]
    |  |     +--rw session-id                     uint32
    |  |     +--rw test-session-enable?           enable
    |  |     +--rw number-of-packets?             union
    |  |     +--rw packet-padding-size?           uint32
    |  |     +--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 sender-udp-port                inet:port-number
    |  |     +--rw reflector-ip                   inet:ip-address
    |  |     +--rw 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?       enable
    |     +--rw ref-wait?               uint32
    |     +--rw reflector-mode-state?   session-reflector-mode
    |     +--rw test-session* [session-id]
    |        +--rw session-id                    uint32
    |        +--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* [session-id]
       |     +--ro session-id              uint32
       |     +--ro sender-session-state?   enumeration
       |     +--ro current-stats
       |     |  +--ro start-time                    yang:date-and-time
       |     |  +--ro packet-padding-size?          uint32
       |     |  +--ro interval?                     uint32
       |     |  +--ro duplicate-packets?            uint32
       |     |  +--ro reordered-packets?            uint32
       |     |  +--ro sender-ip                     inet:ip-address
       |     |  +--ro sender-udp-port               inet:port-number
       |     |  +--ro reflector-ip                  inet:ip-address
       |     |  +--ro reflector-udp-port?           inet:port-number
       |     |  +--ro sender-timestamp-format?      timestamp-format
       |     |  +--ro reflector-timestamp-format?   timestamp-format
       |     |  +--ro dscp?                         inet:dscp
       |     |  +--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 two-way-delay
       |     |  |  +--ro delay
       |     |  |  |  +--ro min?   yang:gauge32
       |     |  |  |  +--ro max?   yang:gauge32
       |     |  |  |  +--ro avg?   yang:gauge32
       |     |  |  +--ro delay-variation
       |     |  |     +--ro min?   uint32
       |     |  |     +--ro max?   uint32
       |     |  |     +--ro avg?   uint32
       |     |  +--ro one-way-delay-far-end
       |     |  |  +--ro delay
       |     |  |  |  +--ro min?   yang:gauge32
       |     |  |  |  +--ro max?   yang:gauge32
       |     |  |  |  +--ro avg?   yang:gauge32
       |     |  |  +--ro delay-variation
       |     |  |     +--ro min?   uint32
       |     |  |     +--ro max?   uint32
       |     |  |     +--ro avg?   uint32
       |     |  +--ro one-way-delay-near-end
       |     |  |  +--ro delay
       |     |  |  |  +--ro min?   yang:gauge32
       |     |  |  |  +--ro max?   yang:gauge32
       |     |  |  |  +--ro avg?   yang:gauge32
       |     |  |  +--ro delay-variation
       |     |  |     +--ro min?   uint32
       |     |  |     +--ro max?   uint32
       |     |  |     +--ro avg?   uint32
       |     |  +--ro low-percentile
       |     |  |  +--ro delay-percentile
       |     |  |  |  +--ro rtt-delay?        percentile
       |     |  |  |  +--ro near-end-delay?   percentile
       |     |  |  |  +--ro far-end-delay?    percentile
       |     |  |  +--ro delay-variation-percentile
       |     |  |     +--ro rtt-delay-variation?        percentile
       |     |  |     +--ro near-end-delay-variation?   percentile
       |     |  |     +--ro far-end-delay-variation?    percentile
       |     |  +--ro mid-percentile
       |     |  |  +--ro delay-percentile
       |     |  |  |  +--ro rtt-delay?        percentile
       |     |  |  |  +--ro near-end-delay?   percentile
       |     |  |  |  +--ro far-end-delay?    percentile
       |     |  |  +--ro delay-variation-percentile
       |     |  |     +--ro rtt-delay-variation?        percentile
       |     |  |     +--ro near-end-delay-variation?   percentile
       |     |  |     +--ro far-end-delay-variation?    percentile
       |     |  +--ro high-percentile
       |     |  |  +--ro delay-percentile
       |     |  |  |  +--ro rtt-delay?        percentile
       |     |  |  |  +--ro near-end-delay?   percentile
       |     |  |  |  +--ro far-end-delay?    percentile
       |     |  |  +--ro delay-variation-percentile
       |     |  |     +--ro rtt-delay-variation?        percentile
       |     |  |     +--ro near-end-delay-variation?   percentile
       |     |  |     +--ro far-end-delay-variation?    percentile
       |     |  +--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 history-stats* [id]
       |        +--ro id                            uint32
       |        +--ro end-time                      yang:date-and-time
       |        +--ro number-of-packets?            uint32
       |        +--ro packet-padding-size?          uint32
       |        +--ro interval?                     uint32
       |        +--ro duplicate-packets?            uint32
       |        +--ro reordered-packets?            uint32
       |        +--ro loss-packets?                 uint32
       |        +--ro sender-ip                     inet:ip-address
       |        +--ro sender-udp-port               inet:port-number
       |        +--ro reflector-ip                  inet:ip-address
       |        +--ro reflector-udp-port?           inet:port-number
       |        +--ro sender-timestamp-format?      timestamp-format
       |        +--ro reflector-timestamp-format?   timestamp-format
       |        +--ro dscp?                         inet:dscp
       |        +--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 two-way-delay
       |        |  +--ro delay
       |        |  |  +--ro min?   yang:gauge32
       |        |  |  +--ro max?   yang:gauge32
       |        |  |  +--ro avg?   yang:gauge32
       |        |  +--ro delay-variation
       |        |     +--ro min?   uint32
       |        |     +--ro max?   uint32
       |        |     +--ro avg?   uint32
       |        +--ro one-way-delay-far-end
       |        |  +--ro delay
       |        |  |  +--ro min?   yang:gauge32
       |        |  |  +--ro max?   yang:gauge32
       |        |  |  +--ro avg?   yang:gauge32
       |        |  +--ro delay-variation
       |        |     +--ro min?   uint32
       |        |     +--ro max?   uint32
       |        |     +--ro avg?   uint32
       |        +--ro one-way-delay-near-end
       |           +--ro delay
       |           |  +--ro min?   yang:gauge32
       |           |  +--ro max?   yang:gauge32
       |           |  +--ro avg?   yang:gauge32
       |           +--ro delay-variation
       |              +--ro min?   uint32
       |              +--ro max?   uint32
       |              +--ro avg?   uint32
       +--ro stamp-session-refl-state {session-reflector}?
          +--ro reflector-light-admin-status    boolean
          +--ro test-session-state* [session-id]
             +--ro session-id                    uint32
             +--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 reflector-timestamp-format?   timestamp-format
             +--ro sender-ip                     inet:ip-address
             +--ro sender-udp-port               inet:port-number
             +--ro reflector-ip                  inet:ip-address
             +--ro reflector-udp-port?           inet:port-number
          

Figure 3: STAMP State Tree Diagram

          
  rpcs:
    +---x stamp-sender-start
    |  +---w input
    |     +---w session-id    uint32
    +---x stamp-sender-stop
       +---w input
          +---w session-id    uint32
          

Figure 4: STAMP RPC Tree Diagram

3.2. YANG Module

          
<CODE BEGINS> file "ietf-stamp@2018-03-01.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";
   }
   import ietf-yang-types {
     prefix yang;
     reference "RFC 6991";
   }
   import ietf-key-chain {
     prefix kc;
     reference "RFC 8177";
   }
   
   organization
     "IETF IPPM (IP Performance Metrics) Working Group";

   contact
     "draft-ietf-ippm-stamp-yang@tools.ietf.org";

   description "STAMP Data Model";

   revision "2018-03-01" {
     description 
     "00 version. Base STAMP specification is covered";
     reference "";
   }

      /*
    * Feature definitions.
    */
     feature session-sender {
     description 
     "This feature relates to the device functions as the 
     STAMP Session-Sender";
   }

   feature session-reflector {
     description 
     "This feature relates to the device functions as the
     STAMP Session-Reflector";
   }

   feature stamp-security {
     description "Secure STAMP supported";
   }
   
   typedef enable {
      type boolean;
      description "enable";
   }

   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";
   }

   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.";
  }

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

   typedef percentile {
   	type decimal64 {
   		fraction-digits 2;
   	}
   	description 
   	"Percentile is a measure used in statistics
   	indicating the value below which a given 
   	percentage of observations in a group of 
   	observations fall.";
   }
     
   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 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:gauge32;
		   units microseconds;
		   description 
		   "Min of Packets transmitted delay";
		 }
		 leaf max {
		    type yang:gauge32;
		    units microseconds;
		    description 
		    "Max of Packets transmitted delay";
		 }
		 leaf avg {
		    type yang:gauge32;
		    units microseconds;
		    description 
		    "Avg of Packets transmitted delay";
		 }
     }

	 container delay-variation {
		 description 
		 "Packets transmitted delay variation";
		 leaf min {
		   type uint32;
		   units microseconds;
		   description 
		   "Min of Packets transmitted
		   delay variation";
		 }
		 leaf max {
		   type uint32;
		   units microseconds;
		   description 
		   "Max of Packets transmitted
		   delay variation";
		 }
		 leaf avg {
		   type uint32;
		   units microseconds;
		   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 percentile;
     			description
     			"Percentile of round-trip delay";
     		}
	     	leaf near-end-delay {
     			type percentile;
     			description
     			"Percentile of near-end delay";
     		}
	     	leaf far-end-delay {
     			type percentile;
     			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 percentile;
     			description
     			"Percentile of round-trip delay-variation";
     		}
	     	leaf near-end-delay-variation {
     			type percentile;
     			description
     			"Percentile of near-end delay variation";
     		}
	     	leaf far-end-delay-variation {
     			type percentile;
     			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 common among 
     Session-Sender and Session-Reflector";
     leaf sender-ip {
       type inet:ip-address;
       mandatory true;
       description "Sender IP address";
     }
     leaf sender-udp-port {
       type inet:port-number {
         range "49152..65535";
       }
       mandatory true;
       description "Sender UDP port number";
     }
     leaf reflector-ip {
       type inet:ip-address;
       mandatory true;
       description "Reflector IP address";
     }
     leaf reflector-udp-port {
       type inet:port-number{
         range "862 | 49152..65535";
       }
       default 862;
       description "Reflector UDP port number";
     }
   }

   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 or encryption";
         leaf key-chain {
            type kc:key-chain-ref;
            description "Name of key-chain";
         }
      }
   }

   /* 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 enable;
         default "true";
         description 
         "Whether this network element is enabled to
         act as STAMP Session-Sender";
       }       
       
       list test-session {
         key "session-id";
	       unique "sender-ip sender-udp-port reflector-ip"
         +" reflector-udp-port dscp-value";
         description 
         "This structure is a container of test session
         managed objects";

         leaf session-id {
           type uint32;
           description "Session ID";
         }

         leaf test-session-enable {
           type enable;
           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 packet-padding-size {
           type uint32;
           default 27;
           description 
           "Size of the Packet Padding. Suggested to run
           Path MTU Discovery to avoid packet fragmentation in
           IPv4 and packet blackholing in IPv6";
         }

         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 enable;
           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 test-session {
          key "session-id";
	        unique "sender-ip sender-udp-port reflector-ip"
          +" reflector-udp-port";
          description 
          "This structure is a container of test session
          managed objects";

        leaf session-id {
          type uint32;
          description "Session ID";
        }

        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 | 49152..65535";
       }
       default 862;
       description "Reflector UDP port number";
     }
     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-id";
       description 
       "This structure is a container of test session
       managed objects";

       leaf session-id {
         type uint32;
         description "Session ID";
       }

       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";
          }

          leaf packet-padding-size {
            type uint32;
            default 27;
            description 
            "Size of the Packet Padding. Suggested to run
            Path MTU Discovery to avoid packet fragmentation 
            in IPv4 and packet blackholing in IPv6";
          }

          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";
          }

          uses session-parameters;
      leaf sender-timestamp-format {
       type timestamp-format;
       default ntp-format;
       description "Sender Timestamp format";
     }
     leaf reflector-timestamp-format {
       type timestamp-format;
       default ntp-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.";
          }
          uses maintenance-statistics;

          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/"
          	+"test-session[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/"
          	+"test-session[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/"
          	+"test-session[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/"
            +"test-session[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/"
            +"test-session[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;
          }
       }

       list history-stats {
         key id;
         description
         "This container contains the results for the history
          Measurement Interval in a Measurement session ";
          leaf id {
            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";
          }
          leaf number-of-packets {
            type uint32;
            description 
            "The overall number of UDP test packets to be
            transmitted by the sender for this test session";
          }

          leaf packet-padding-size {
            type uint32;
            default 27;
            description 
            "Size of the Packet Padding. Suggested to run
            Path MTU Discovery to avoid packet fragmentation 
            in IPv4 and packet blackholing in IPv6";
          }

          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 loss-packets  {
            type uint32;
           description "Loss packets";
          }

          uses session-parameters;
      leaf sender-timestamp-format {
       type timestamp-format;
       default ntp-format;
       description "Sender Timestamp format";
     }
     leaf reflector-timestamp-format {
       type timestamp-format;
       default ntp-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.";
          }
          uses maintenance-statistics;

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

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

       leaf session-id {
         type uint32;
         description "Session ID";
       }

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

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

 rpc stamp-sender-stop {
   description
	 "stop the configured sender session";
   input {
  	 leaf 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 [RFC6020].

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 [RFC5246].

The NETCONF access control model [RFC6536] provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured 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 a negative 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 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:

/ietf-vrrp:stamp

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. Acknowledgements

Authors recognize and appreciate valuable comments provided by Adrian Pan.

7. Normative References

[I-D.ietf-ippm-stamp] Mirsky, G., Jun, G. and H. Nydell, "Simple Two-way Active Measurement Protocol", Internet-Draft draft-ietf-ippm-stamp-00, January 2018.
[I-D.ietf-netmod-revised-datastores] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K. and R. Wilton, "Network Management Datastore Architecture", Internet-Draft draft-ietf-netmod-revised-datastores-10, January 2018.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, DOI 10.17487/RFC5246, August 2008.
[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, October 2008.
[RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010.
[RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J. and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011.
[RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration Protocol (NETCONF) Access Control Model", RFC 6536, DOI 10.17487/RFC6536, March 2012.
[RFC7750] Hedin, J., Mirsky, G. and S. Baillargeon, "Differentiated Service Code Point and Explicit Congestion Notification Monitoring in the Two-Way Active Measurement Protocol (TWAMP)", RFC 7750, DOI 10.17487/RFC7750, February 2016.
[RFC8040] Bierman, A., Bjorklund, M. and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017.

Appendix A. Example of STAMP Session Configuration

Figure 5 shows a configuration example for 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>
            <session-id>10</session-id>
            <test-session-enable>enable<test-session-enable>
            <number-of-packets>forever</number-of-packets>
            <packet-padding-size/> <!-- use default 27 octets -->
            <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>
            <sender-udp-port></sender-udp-port>
            <reflector-ip></reflector-ip>
            <reflector-udp-port/> <!-- use default 862 -->
            <sender-timestamp-format/>
            <!-- No authentication or encryption -->
            <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/> 
          <session-id></session-id>
          <!-- 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 or encryption -->
        </stamp-session-reflector>
     </stamp>
   </data>

Figure 6: XML instance of STAMP Session-Reflector configuration

Authors' Addresses

Greg Mirsky ZTE Corp. EMail: gregimirsky@gmail.com
Xiao Min ZTE Corp. EMail: xiao.min2@zte.com.cn
Wei S Luo Ericsson EMail: wei.s.luo@ericsson.com