BESS Working Group                                               M. Wang
Internet-Draft                                                     Q. Wu
Intended status: Standards Track                                 R. Even
Expires: May 3, 2020                                              Huawei
                                                                  B. Wen
                                                                 Comcast
                                                                  C. Liu
                                                            China Unicom
                                                                   H. Xu
                                                           China Telecom
                                                        October 31, 2019


    A YANG Model for Network and VPN Service Performance Monitoring
                 draft-www-bess-yang-vpn-service-pm-04

Abstract

   The data model defined in [RFC8345] introduces vertical layering
   relationships between networks that can be augmented to cover
   network/service topologies.  This document defines a YANG model for
   both Network Performance Monitoring and VPN Service Performance
   Monitoring that can be used to monitor and manage network performance
   on the topology at higher layer or the service topology between VPN
   sites.  This model is an augmentation to the network topology YANG
   data model defined in [RFC8345].

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 May 3, 2020.








Wang, et al.               Expires May 3, 2020                  [Page 1]


Internet-Draft       Network and VPN Service PM YANG        October 2019


Copyright Notice

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

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions used in this document . . . . . . . . . . . . . .   3
     2.1.  Tree Diagrams . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Network and VPN service assurance module  . . . . . . . . . .   3
   4.  Layering relationship between multiple layers of topology . .   4
   5.  Model Usage Guideline . . . . . . . . . . . . . . . . . . . .   5
     5.1.  Performance Monitoring Data Source  . . . . . . . . . . .   5
     5.2.  Retrieval via I2RS Pub/Sub [RFC7923]  . . . . . . . . . .   5
     5.3.  On demand Retrieval via RPC model . . . . . . . . . . . .   5
   6.  Design of the Data Model  . . . . . . . . . . . . . . . . . .   5
     6.1.  Network Level . . . . . . . . . . . . . . . . . . . . . .   6
     6.2.  Node Level  . . . . . . . . . . . . . . . . . . . . . . .   6
     6.3.  Link and Termination Point Level  . . . . . . . . . . . .   7
   7.  Example of I2RS Pub/Sub Retrieval [RFC7923] . . . . . . . . .   8
   8.  Example of RPC model based Retrieval  . . . . . . . . . . . .  10
   9.  Network and VPN Service Assurance YANG Module . . . . . . . .  11
   10. Security Considerations . . . . . . . . . . . . . . . . . . .  20
   11. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  21
   12. Normative References  . . . . . . . . . . . . . . . . . . . .  22
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  23

1.  Introduction

   [RFC8345] defines an abstract YANG data model for network/service
   topologies and inventories.  Service topology described in [RFC8345]
   includes the a virtual topology for a service layer above the L1, L2,
   and L3 layers.  This service topology has the generic topology
   elements of node, link, and terminating point.  One typical example
   of a service topology is described in figure 3 of [RFC8345], two VPN
   service topologies instantiated over a common L3 topology.  Each VPN




Wang, et al.               Expires May 3, 2020                  [Page 2]


Internet-Draft       Network and VPN Service PM YANG        October 2019


   service topology is mapped onto a subset of nodes from the common L3
   topology.

   In [RFC8299], 3 types of VPN service topologies are defined for the
   L3VPN service data model: any to any; hub and spoke; and hub and
   spoke disjoint.  These VPN topology types can be used to describe how
   VPN sites communicate with each other.

   This document defines a YANG Model for both Network performance
   monitoring and VPN Service Performance Monitoring that can be used to
   monitor and manage network Performance on the topology at higher
   layer or the service topology between VPN sites and it is an
   augmentation to the network topology YANG data model defined in
   [RFC8345].

2.  Conventions used in this document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].  In this
   document, these words will appear with that interpretation only when
   in ALL CAPS.  Lower case uses of these words are not to be
   interpreted as carrying [RFC2119] significance.

2.1.  Tree Diagrams

   Tree diagrams used in this document follow the notation defined in
   [RFC8340].

3.  Network and VPN service assurance module

   This module defined in this document is a Network and VPN Service
   assurance module that can be used to monitor and manage the network
   Performance on the topology at higher layer layer or the service
   topology between VPN sites and it is an augmentation to the "ietf-
   network" and "ietf-network-topology" YANG data model [RFC8345].  The
   performance monitoring data is augmented to service topology.

   +----------------------+          +-----------------------+
   |ietf-network          |          |Network and VPN Service|
   |ietf-network-topology |<---------|Peformance Monitoring  |
   +----------------------+ augments |        Model          |
                                     +-----------------------+








Wang, et al.               Expires May 3, 2020                  [Page 3]


Internet-Draft       Network and VPN Service PM YANG        October 2019


4.  Layering relationship between multiple layers of topology

   The data model defined in [RFC8345] can describe vertical layering
   relationships between networks.  That model can be augmented to cover
   network/service topologies.

   Figure 1 describes an example on topology mapping between the VPN
   service topology and the underlying network:

                VPN-SVC 1           VPN-SVC 2
                   /                     \
      VPN-Service-topology 1     VPN-Service-topology-2
          /     |      \            /     |      \
     Site-1A Site-1B Site1-C    Site-2A Site-2B Site-2C    Top-Down
       |          |       |       |         |     |     Service Topology
       CE         CE     CE      CE        CE     CE
       |          |       |       |         |     |
       PE         PE     PE      PE        PE     PE
   ====|==========|=======|=======|=========|=====|======================
       +-------+  |        \    /           /     |
    Bottom-up  |  |         \ /           /       |
    Network    |  |         /\           /        |
    topology   |  |       /    \        |         |
               |  |      |       |      |         |
           node1 node2 node3   node4   node5    node6

    Example of topology mapping between VPN Service Topo and Underlying
                                  network

   As shown in Figure 1, Site-1A, Site-1B, and Site-1C are mapped to
   nodes 1, 2, and 3, while Site-2A, Site-2B, and Site-2C are mapped to
   nodes 4, 5, and 6 in the underlying physical network.  In this
   figure, two VPN services topologies are both built on top of one
   common underlying physical network.

      VPN-SVC 1: supporting hub-spoke communication for Customer 1
      connecting the customers access at 3 sites

      VPN-SVC 2: supporting hub-spoke disjoint communication for
      Customer 2 connecting the customers access at 3 sites

   VPN service topology 1 is hub and spoke topology while VPN service
   topology 2 is hub and spoke disjoint topology.  In VPN service
   topology 1, Site-1 A plays the role of hub while Site-2 B and C plays
   the role of spoke.  In VPN service topoogy 2, Site-2 A and B play the
   role of hub while Site-2 C plays the role of spoke.





Wang, et al.               Expires May 3, 2020                  [Page 4]


Internet-Draft       Network and VPN Service PM YANG        October 2019


5.  Model Usage Guideline

   An SP must be able to manage the capabilities and characteristics of
   their Network/VPN services when Network connection is established or
   VPN sites are setup to communicate with each other.  VPN service
   topology such as hub and spoke describes how these VPN sites are
   communicating with each other.

5.1.  Performance Monitoring Data Source

   As described in Section 4, once the mapping between VPN Service
   topology and underlying physical network has been setup, the
   performance monitoring data per link in the underlying network can be
   collected using network performance measurement method such as MPLS
   Loss and Delay Measurement [RFC6374].  The performance monitoring
   information reflecting the quality of the Network or VPN service such
   as end to end network performance data between source node and
   destination node in the network or between VPN sites can be
   aggregated or calculated using PCEP solution [RFC5440] or LMAP
   solution [RFC8194].  The information can be fed into data source such
   as the management system or network devices.  The measurement
   interval and report interval associated with these performance data
   usually depends on configuration parameters.

5.2.  Retrieval via I2RS Pub/Sub [RFC7923]

   Some applications such as service-assurance applications, which must
   maintain a continuous view of operational data and state, can use
   subscription model [I-D.ietf-netconf-yang-push] to subscribe to the
   Network performance data or VPN service performance data they are
   interested in, at the data source.

   The data source can then use the Network and VPN service assurance
   model defined in this document and push model [I-D.ietf-netconf-yang-
   push] to distribute specific telemetry data to target recipients.

5.3.  On demand Retrieval via RPC model

   To obtain a snapshot of a large amount of performance data from the
   network element, service-assurance applications can also use polling
   based solution such as RPC model to fetch performance data on demand.

6.  Design of the Data Model

   This document defines the YANG module "ietf-network-vpn-pm", which
   has the following structure





Wang, et al.               Expires May 3, 2020                  [Page 5]


Internet-Draft       Network and VPN Service PM YANG        October 2019


6.1.  Network Level

      module: ietf-network-vpn-pm
        augment /nw:networks/nw:network/nw:network-types:
          +--rw network-technology-type*   identityref
        augment /nw:networks/nw:network:
          +--rw vpn-topo-attributes
             +--rw vpn-topo?   identityref

                   Network Level View of the hierarchies

   For VPN service performance monitoring, this model defines only the
   following minimal set of Network level network topology attributes:

   o  Network-technology-type: Indicate the network technology type such
      as L3VPN, L2VPN,ISIS, OSPF.  If the network-technology-type is VPN
      type,e.g.,L3VPN, L2VPN, the VPN-topo should be set.

   o  vpn-topo: The type of VPN service topology, this model supports
      any-to-any, Hub and Spoke (where Hubs can exchange traffic), and
      "Hub and Spoke disjoint" (where Hubs cannot exchange traffic).

   For network performance monitoring, the attributes of "Network Level"
   that defined in [RFC8345] do not need to be extended.

6.2.  Node Level

   augment /nw:networks/nw:network/nw:node:
       +--rw node-attributes
          +--rw node-type?   identityref
          +--rw site-id?     string
          +--rw site-role?   Identityref

                    Node Level View of the hierarchies

   The Network and VPN service performance monitoring model defines only
   the following minimal set of Node level network topology attributes
   and constraints:

   o  Node-type (Attribute): Indicate the type of the node, such as PE
      or ASBR.

   o  Site-id (Constraint): Uniquely identifies the site within the
      overall network infrastructure.

   o  Site-role (Constraint): Defines the role of the site in a
      particular VPN topology.




Wang, et al.               Expires May 3, 2020                  [Page 6]


Internet-Draft       Network and VPN Service PM YANG        October 2019


6.3.  Link and Termination Point Level

     augment /nw:networks/nw:network/nt:link:
       +--rw link-type?                        identityref
       +--ro link-telemetry-attributes
          +--ro loss-statistics
          |  +--ro direction                   identityref
          |  +--ro packet-loss-count?          uint32
          |  +--ro loss-ratio?                 percentage
          |  +--ro packet-reorder-count?       uint32
          |  +--ro packets-out-of-seq-count?   uint32
          |  +--ro packets-dup-count?          uint32
          +--ro delay-statistics
          |  +--ro direction?                identityref
          |  +--ro min-delay-value?          uint32
          |  +--ro max-delay-value?          uint32
          |  +--ro average-delay-value?      uint32
          +--ro jitter-statistics
             +--ro direction?                identityref
             +--ro min-jitter-value?         uint32
             +--ro max-jitter-value?         uint32
             +--ro average-jitter-value?     uint32
     augment /nw:networks/nw:network/nw:node/nt:termination-point:
       +--ro tp-telemetry-attributes
          +--ro in-octets?           uint32
          +--ro inbound-unicast?     uint32
          +--ro inbound-nunicast?    uint32
          +--ro inbound-discards?    uint32
          +--ro inbound-errors?      uint32
          +--ro inunknow-protos?     uint32
          +--ro out-octets?          uint32
          +--ro outbound-unicast?    uint32
          +--ro outbound-nunicast?   uint32
          +--ro outbound-discards?   uint32
          +--ro outbound-errors?     uint32
          +--ro outbound-qlen?       uint32

         Link and Termination point Level View of the hierarchies

   The Network and VPN service performance monitoring model defines only
   the following minimal set of Link level network topology attributes:

   o  Link-type (Attribute): Indicate the type of the link, such as
      GRE,IP in IP.

   o  Loss Statistics: A set of loss statistics attributes that are used
      to measure end to end loss between VPN sites.




Wang, et al.               Expires May 3, 2020                  [Page 7]


Internet-Draft       Network and VPN Service PM YANG        October 2019


   o  Delay Statistics: A set of delay statistics attributes that are
      used to measure end to end latency between VPN sites.

   o  Jitter Statistics: A set of jitter statistics attributes that are
      used to measure end to end jitter between VPN sites.

   The Network and VPN service performance monitoring defines the
   following minimal set of Termination point level network topology
   attributes:

   o  Inbound statistics: A set of inbound statistics attributes that
      are used to measure the inbound statistics of the termination
      point, such as "the total number of octets received on the
      termination point", "The number of inbound packets which were
      chosen to be discarded", "The number of inbound packets that
      contained errors", etc.

   o  Outbound statistics: A set of outbound statistics attributes that
      are used to measure the outbound statistics of the termination
      point, such as "the total number of octets transmitted out of the
      termination point", "The number of outbound packets which were
      chosen to be discarded", "The number of outbound packets that
      contained errors", etc.

7.  Example of I2RS Pub/Sub Retrieval [RFC7923]

   This example shows the way for a client to subscribe for the
   Performance monitoring information between node A and node B in the
   L3 network topology built on top of the underlying network . The
   performance monitoring parameter that the client is interested in is
   end to end loss attribute.

    <rpc netconf:message-id="101"
       xmlns:netconf="urn:ietf:params:xml:ns:netconf:base:1.0">
       <establish-subscription
          xmlns="urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications">
          <stream-subtree-filter>
             <networks xmlns="urn:ietf:params:xml:ns:yang:ietf-network-topo">
                <network>
                 <network-id>l3-network</network-id>
                 <network-technology-type xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
                 L3VPN
                 </network-technology-type>
                  <node>
                   <node-id>A</node-id>
                   <node-attributes xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
                    <node-type>pe</node-type>
                   </node-attribtues>



Wang, et al.               Expires May 3, 2020                  [Page 8]


Internet-Draft       Network and VPN Service PM YANG        October 2019


                   <termination-point xmlns="urn:ietf:params:xml:ns:yang:ietf-network-topology">
                    <tp-id>1-0-1</tp-id>
                   <tp-telemetry-attributes xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
                     <in-octets>100</in-octets>
                     <out-octets>150</out-octets>
                    </tp-telemetry-attributes>
                   </termination-point>
                  </node>
                  <node>
                   <node-id>B</node-id>
                   <node-attributes xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
                    <node-type>pe</node-type>
                   </node-attribtues>
                   <termination-point xmlns="urn:ietf:params:xml:ns:yang:ietf-network-topology">
                    <tp-id>2-0-1</tp-id>
                   <tp-telemetry-attributes xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
                     <in-octets>150</in-octets>
                     <out-octets>100</out-octets>
                    </tp-telemetry-attributes>
                   </termination-point>
                  </node>
                  <link xmlns="urn:ietf:params:xml:ns:yang:ietf-network-topology">
                   <link-id>A-B</link-id>
                   <source>
                    <source-node>A</source-node>
                   </source>
                   <destination>
                    <dest-node>B</dest-node>
                   </destination>
                    <link-type>mpls-te</link-type>
                    <link-telemetry-attributes
                     xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
                     <loss-statistics>
                      <packet-loss-count>100</packet-loss-count>
                     </loss-statistics>
                    </link-telemetry-attributes>
                   </link>
                </network>
             </networks>
          </stream-subtree-filter>
          <period xmlns="urn:ietf:params:xml:ns:yang:ietf-yang-push:1.0">500</period>
       </establish-subscription>
    </rpc>








Wang, et al.               Expires May 3, 2020                  [Page 9]


Internet-Draft       Network and VPN Service PM YANG        October 2019


8.  Example of RPC model based Retrieval

   This example shows the way for the client to use RPC model to fetch
   performance data on demand,e.g., the client requests packet-loss-
   count between PE1 in site 1 and PE2 in site 2 belonging to the same
   VPN1.

    <rpc xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"
        message-id="1">
     <report xmlns="urn:ietf:params:xml:ns:yang:example-service-pm-report">
      <networks xmlns="urn:ietf:params:xml:ns:yang:ietf-network-topo">
        <network>
         <network-id>vpn1</network-id>
         <node>
          <node-id>A</node-id>
          <node-attributes xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
          <node-type>pe</node-type>
          </node-attribtues>
          <termination-point xmlns="urn:ietf:params:xml:ns:yang:ietf-network-topology">
           <tp-id>1-0-1</tp-id>
           <tp-telemetry-attributes xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
            <in-octets>100</in-octets>
            <out-octets>150</out-octets>
           </tp-telemetry-attributes>
          </termination-point>
         </node>
         <node>
          <node-id>B</node-id>
          <node-attributes xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
          <node-type>pe</node-type>
          </node-attribtues>
          <termination-point xmlns="urn:ietf:params:xml:ns:yang:ietf-network-topology">
           <tp-id>2-0-1</tp-id>
           <tp-telemetry-attributes xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
            <in-octets>150</in-octets>
            <out-octets>100</out-octets>
           </tp-telemetry-attributes>
          </termination-point>
         </node>
         <link-id>A-B</link-id>
          <source>
           <source-node>A</source-node>
          </source>
          <destination>
           <dest-node>B</dest-node>
          </destination>
           <link-type>mpls-te</link-type>
          <telemetry-attributes xmlns="urn:ietf:params:xml:ns:yang:ietf-network-pm">



Wang, et al.               Expires May 3, 2020                 [Page 10]


Internet-Draft       Network and VPN Service PM YANG        October 2019


           <loss-statistics>
            <packet-loss-count>120</packet-loss-count>
           </loss-statistics>
          </telemetry-attributes>
         </link>
       </network>
     </report>
   </rpc>

9.  Network and VPN Service Assurance YANG Module

<CODE BEGINS> file "ietf-network-vpn-pm.yang"
module ietf-network-vpn-pm {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm";
  prefix nvp;

  import ietf-network {
    prefix nw;
  }
  import ietf-network-topology {
    prefix nt;
  }
  import ietf-l3vpn-svc {
    prefix l3vpn-svc;
  }

  organization
    "IETF BESS Working Group";
  contact
    "Zitao Wang: wangzitao@huawei.com
     Qin Wu: bill.wu@huawei.com";
  description
    "This module defines a model for the VPN Service Performance monitoring.";

  revision 2019-03-01 {
    description
      "Initial revision.";
    reference
      "foo";
  }

  identity network-type {
    description
      "Base type for Overlay network topology";
  }

  identity l3vpn {



Wang, et al.               Expires May 3, 2020                 [Page 11]


Internet-Draft       Network and VPN Service PM YANG        October 2019


    base network-type;
    description
      "Indentity for layer3 vpn network type.";
  }

  identity l2vpn {
    base network-type;
    description
      "Identity for layer2 vpn network type.";
  }

  identity ospf {
    base network-type;
    description
      "Identity for OSPF network type.";
  }

  identity isis {
    base network-type;
    description
      "Identity for ISIS network type.";
  }
  identity node-type {
    description
      "Base identity for node type";
  }

  identity pe {
    base node-type;
    description
      "Identity for PE type";
  }

  identity ce {
    base node-type;
    description
      "Identity for CE type";
  }

  identity asbr {
    base node-type;
    description
      "Identity for ASBR type";
  }

  identity p {
    base node-type;
    description



Wang, et al.               Expires May 3, 2020                 [Page 12]


Internet-Draft       Network and VPN Service PM YANG        October 2019


      "Identity for P type";
  }

  identity link-type {
    description
      "Base identity for link type,e.g.,GRE, MPLS TE, VXLAN.";
  }
  identity gre {
    base link-type;
    description
      "Base identity for GRE Tunnel.";
  }
  identity VXLAN {
    base link-type;
    description
      "Base identity for VXLAN Tunnel.";
  }
  identity ip-in-ip {
    base link-type;
    description
      "Base identity for IP in IP Tunnel.";
  }
  identity direction {
    description
      "Base Identity for measurement direction including
       one way measurement and two way measurement.";
  }

  identity oneway {
    base direction;
    description
      "Identity for one way measurement.";
  }

  identity twoway {
    base direction;
    description
      "Identity for two way measurement.";
  }
  typedef percentage {
    type decimal64 {
      fraction-digits 5;
      range "0..100";
    }
    description
      "Percentage.";
  }




Wang, et al.               Expires May 3, 2020                 [Page 13]


Internet-Draft       Network and VPN Service PM YANG        October 2019


  grouping link-error-statistics {
    description
      "Grouping for per link error statistics";
    container loss-statistics {
      description
        "Per link loss statistics.";
      leaf direction {
        type identityref {
          base direction;
        }
        default "oneway";
        description
          "Define measurement direction including one way
           measurement and two way measurement.";
      }
      leaf packet-loss-count {
        type uint32 {
          range "0..4294967295";
        }
        default "0";
        description
          "Total received packet drops count.
           The value of count will be set to zero (0)
           on creation and will thereafter increase
           monotonically until it reaches a maximum value
           of 2^32-1 (4294967295 decimal), when it wraps
           around and starts increasing again from zero.";
      }
      leaf loss-ratio {
        type percentage;
        description
          "Loss ratio of the packets. Express as percentage
           of packets lost with respect to packets sent.";
      }
      leaf packet-reorder-count {
        type uint32 {
          range "0..4294967295";
        }
        default "0";
        description
          "Total received packet reordered count.
           The value of count will be set to zero (0)
           on creation and will thereafter increase
           monotonically until it reaches a maximum value
           of 2^32-1 (4294967295 decimal), when it wraps
           around and starts increasing again from zero.";
      }
      leaf packets-out-of-seq-count {



Wang, et al.               Expires May 3, 2020                 [Page 14]


Internet-Draft       Network and VPN Service PM YANG        October 2019


        type uint32 {
          range "0..4294967295";
        }
        description
          "Total received out of sequence count.
           The value of count will be set to zero (0)
           on creation and will thereafter increase
           monotonically until it reaches a maximum value
           of 2^32-1 (4294967295 decimal), when it wraps
           around and starts increasing again from zero..";
      }
      leaf packets-dup-count {
        type uint32 {
          range "0..4294967295";
        }
        description
          "Total received packet duplicates count.
           The value of count will be set to zero (0)
           on creation and will thereafter increase
           monotonically until it reaches a maximum value
           of 2^32-1 (4294967295 decimal), when it wraps
           around and starts increasing again from zero.";
      }
    }
  }

  grouping link-delay-statistics {
    description
      "Grouping for per link delay statistics";
    container delay-statistics {
      description
        "Link delay summarised information. By default,
         one way measurement protocol (e.g., OWAMP) is used
         to measure delay.";
      leaf direction {
        type identityref {
          base direction;
        }
        default "oneway";
        description
          "Define measurement direction including one way
           measurement and two way measurement.";
      }
      leaf min-delay-value {
        type uint32;
        description
          "Minimum delay value observed.";
      }



Wang, et al.               Expires May 3, 2020                 [Page 15]


Internet-Draft       Network and VPN Service PM YANG        October 2019


      leaf max-delay-value {
        type uint32;
        description
          "Maximum delay value observed.";
      }
      leaf average-delay-value {
        type uint32;
        description
          "Average delay is calculated on all the packets of a sample
           and is a simple computation to be performed for single marking method.";
      }
    }
  }

  grouping link-jitter-statistics {
    description
      "Grouping for per link jitter statistics";
    container jitter-statistics {
      description
        "Link jitter summarised information. By default,
         jitter is measured using IP Packet Delay Variation
         (IPDV) as defined in RFC3393.";
      leaf direction {
        type identityref {
          base direction;
        }
        default "oneway";
        description
          "Define measurement direction including one way
           measurement and two way measurement.";
      }
      leaf min-jitter-value {
        type uint32;
        description
          "Minimum jitter value observed.";
      }
      leaf max-jitter-value {
        type uint32;
        description
          "Maximum jitter value observed.";
      }
      leaf average-jitter-value {
        type uint32;
        description
          "Average jitter is calculated on all the packets of a sample
           and is a simple computation to be performed for single marking method.";
      }
    }



Wang, et al.               Expires May 3, 2020                 [Page 16]


Internet-Draft       Network and VPN Service PM YANG        October 2019


  }

  grouping tp-svc-telemetry {

    leaf in-octets {
      type uint32;
      description
        "The total number of octets received on the
         interface, including framing characters.";
    }
    leaf inbound-unicast {
      type uint32;
      description
        "Inbound unicast packets were received, and delivered
         to a higher layer during the last period.";
    }
    leaf inbound-nunicast {
      type uint32;
      description
        "The number of non-unicast (i.e., subnetwork-
         broadcast or subnetwork-multicast) packets
         delivered to a higher-layer protocol.";
    }
    leaf inbound-discards {
      type uint32;
      description
        "The number of inbound packets which were chosen
         to be discarded even though no errors had been
         detected to prevent their being deliverable to a
         higher-layer protocol.";
    }
    leaf inbound-errors {
      type uint32;
      description
        "The number of inbound packets that contained
         errors preventing them from being deliverable to a
         higher-layer protocol.";
    }
    leaf inunknow-protos {
      type uint32;
      description
        "The number of packets received via the interface
         which were discarded because of an unknown or
         unsupported protocol";
    }
    leaf out-octets {
      type uint32;
      description



Wang, et al.               Expires May 3, 2020                 [Page 17]


Internet-Draft       Network and VPN Service PM YANG        October 2019


        "The total number of octets transmitted out of the
         interface, including framing characters";
    }
    leaf outbound-unicast {
      type uint32;
      description
        "The total number of packets that higher-level
         protocols requested be transmitted to a
         subnetwork-unicast address, including those that
         were discarded or not sent.";
    }
    leaf outbound-nunicast {
      type uint32;
      description
        "The total number of packets that higher-level
         protocols requested be transmitted to a non-
         unicast (i.e., a subnetwork-broadcast or
         subnetwork-multicast) address, including those
         that were discarded or not sent.";
    }
    leaf outbound-discards {
      type uint32;
      description
        "The number of outbound packets which were chosen
         to be discarded even though no errors had been
         detected to prevent their being transmitted.  One
         possible reason for discarding such a packet could
         be to free up buffer space.";
    }
    leaf outbound-errors {
      type uint32;
      description
        "The number of outbound packets that contained
         errors preventing them from being deliverable to a
         higher-layer protocol.";
    }
    leaf outbound-qlen {
      type uint32;
      description
        " Length of the queue of the interface from where
          the packet is forwarded out.  The queue depth could
           be the current number of memory buffers used by the
          queue and a packet can consume one or more memory buffers
          thus constituting device-level information.";
    }
    description
      "Grouping for interface service telemetry";
  }



Wang, et al.               Expires May 3, 2020                 [Page 18]


Internet-Draft       Network and VPN Service PM YANG        October 2019


  augment "/nw:networks/nw:network/nw:network-types" {
    description
      "Augment the network-types with service topologyies types";
    leaf-list network-technology-type {
      type identityref {
        base network-type;
      }
      description
        "Identify the network technology type,e.g.,L3VPN,L2VPN, ISIS, OSPF.";
    }
  }
  augment "/nw:networks/nw:network" {
    description
      "Augment the network with service topology attributes";
    container overlay-topo-attributes {
      leaf vpn-topology {
        type identityref {
          base l3vpn-svc:vpn-topology;
        }
        description
          "VPN service topology, e.g. hub-spoke, any-to-any, hub-spoke-disjoint, etc";
      }
      description
        "Container for vpn services";
    }
  }
  augment "/nw:networks/nw:network/nw:node" {
    description
      "Augment the network node with overlay topology attributes";
    container node-attributes {
      leaf node-type {
        type identityref {
          base node-type;
        }
        description
          "Node type, e.g. PE, P, ASBR, etc";
      }
      leaf site-id {
        type string;
        description
          "Asscoiated vpn site";
      }
      leaf site-role {
        type identityref {
          base l3vpn-svc:site-role;
        }
        default "l3vpn-svc:any-to-any-role";
        description



Wang, et al.               Expires May 3, 2020                 [Page 19]


Internet-Draft       Network and VPN Service PM YANG        October 2019


          "Role of the site in the VPN.";
      }
      description
        "Container for overlay topology attributes";
    }
  }
  augment "/nw:networks/nw:network/nt:link" {
    description
      "Augment the network topology link with overlay topology attributes";
     leaf link-type {
        type identityref {
          base link-type;
        }
        description
          "Link type, e.g. GRE,VXLAN,IP in IP, etc";
      }
    container link-telemetry-attributes {
      config false;
      uses link-error-statistics;
      uses link-delay-statistics;
      uses link-jitter-statistics;
      description
        "Container for service telemetry attributes";
    }
  }
  augment "/nw:networks/nw:network/nw:node/nt:termination-point" {
    description
      "Augment the network topology termination point with vpn service attributes";
    container tp-telemetry-attributes {
      config false;
      uses tp-svc-telemetry;
      description
        "Container for termination point service telemetry attributes.";
    }
  }
}

<CODE ENDS>

10.  Security Considerations

   The YANG modules defined in this document MAY be accessed via the
   RESTCONF protocol [RFC8040] or NETCONF protocol ([RFC6241]).  The
   lowest RESTCONF or NETCONF layer requires that the transport-layer
   protocol provides both data integrity and confidentiality, see
   Section 2 in [RFC8040] and [RFC6241].  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



Wang, et al.               Expires May 3, 2020                 [Page 20]


Internet-Draft       Network and VPN Service PM YANG        October 2019


   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:

   o  /nw:networks/nw:network/svc-topo:svc-telemetry-attributes

   o  /nw:networks/nw:network/nw:node/svc-topo:node-attributes

11.  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-network-vpn-pm

      Registrant Contact: The IESG.

      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-network-vpn-pm
      Namespace:    urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm
      Prefix:       nvp
      Reference:    RFC xxxx
   ---------------------------------------------------------------------








Wang, et al.               Expires May 3, 2020                 [Page 21]


Internet-Draft       Network and VPN Service PM YANG        October 2019


12.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", March 1997.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.

   [RFC5440]  Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation
              Element (PCE) Communication Protocol (PCEP)", RFC 5440,
              DOI 10.17487/RFC5440, March 2009,
              <https://www.rfc-editor.org/info/rfc5440>.

   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <https://www.rfc-editor.org/info/rfc6020>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
              <https://www.rfc-editor.org/info/rfc6242>.

   [RFC6370]  Bocci, M., Swallow, G., and E. Gray, "MPLS Transport
              Profile (MPLS-TP) Identifiers", RFC 6370,
              DOI 10.17487/RFC6370, September 2011,
              <https://www.rfc-editor.org/info/rfc6370>.

   [RFC6374]  Frost, D. and S. Bryant, "Packet Loss and Delay
              Measurement for MPLS Networks", RFC 6374,
              DOI 10.17487/RFC6374, September 2011,
              <https://www.rfc-editor.org/info/rfc6374>.

   [RFC6536]  Bierman, A. and M. Bjorklund, "Network Configuration
              Protocol (NETCONF) Access Control Model", RFC 6536,
              DOI 10.17487/RFC6536, March 2012,
              <https://www.rfc-editor.org/info/rfc6536>.

   [RFC7923]  Voit, E., Clemm, A., and A. Gonzalez Prieto, "Requirements
              for Subscription to YANG Datastores", RFC 7923,
              DOI 10.17487/RFC7923, June 2016,
              <https://www.rfc-editor.org/info/rfc7923>.




Wang, et al.               Expires May 3, 2020                 [Page 22]


Internet-Draft       Network and VPN Service PM YANG        October 2019


   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

   [RFC7952]  Lhotka, L., "Defining and Using Metadata with YANG",
              RFC 7952, DOI 10.17487/RFC7952, August 2016,
              <https://www.rfc-editor.org/info/rfc7952>.

   [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
              BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
              <https://www.rfc-editor.org/info/rfc8340>.

   [RFC8345]  Clemm, A., Medved, J., Varga, R., Bahadur, N.,
              Ananthakrishnan, H., and X. Liu, "A YANG Data Model for
              Network Topologies", RFC 8345, DOI 10.17487/RFC8345, March
              2018, <https://www.rfc-editor.org/info/rfc8345>.

Authors' Addresses

   Michael Wang
   Huawei Technologies,Co.,Ltd
   101 Software Avenue, Yuhua District
   Nanjing  210012
   China

   Email: wangzitao@huawei.com


   Qin Wu
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: bill.wu@huawei.com


   Roni Even
   Huawei Technologies,Co.,Ltd
   Tel Aviv
   Israel

   Email: roni.even@huawei.com








Wang, et al.               Expires May 3, 2020                 [Page 23]


Internet-Draft       Network and VPN Service PM YANG        October 2019


   Bin Wen
   Comcast

   Email: bin_wen@comcast.com


   Change Liu
   China Unicom

   Email: liuc131@chinaunicom.cn


   Honglei Xu
   China Telecom

   Email: xuhl.bri@chinatelecom.cn



































Wang, et al.               Expires May 3, 2020                 [Page 24]