BESS Working Group M. Wang Internet-Draft Q. Wu Intended status: Standards Track R. Even Expires: April 25, 2019 Huawei B. Wen Comcast October 22, 2018 A YANG Model for VPN Service Performance Monitoring draft-www-bess-yang-vpn-service-pm-01 Abstract As specified in [RFC8345], 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 VPN Service Performance Monitoring that can be used to monitor and manage network Performance between VPN sites and it is an augmentation to the I2RS network topology YANG data model. 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 April 25, 2019. 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 Wang, et al. Expires April 25, 2019 [Page 1] Internet-Draft Service Topo YANG October 2018 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 3. VPN Service Topology Overview . . . . . . . . . . . . . . . . 4 4. VPN service assurance model . . . . . . . . . . . . . . . . . 5 5. Model Usage Guideline . . . . . . . . . . . . . . . . . . . . 5 5.1. Performance Monitoring Data Source . . . . . . . . . . . 5 5.2. Retrieval via I2RS Pub/Sub . . . . . . . . . . . . . . . 5 5.3. On demand Retrieval via RPC model . . . . . . . . . . . . 6 6. Design of the Data Model . . . . . . . . . . . . . . . . . . 6 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 . . . . . . . . . . . . . . 8 8. Example of RPC model based Retrieval . . . . . . . . . . . . 9 9. VPN Service Assurance YANG Module . . . . . . . . . . . . . . 9 10. Security Considerations . . . . . . . . . . . . . . . . . . . 16 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 12. Normative References . . . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18 1. Introduction [RFC8345] defines an abstract YANG data model for network/service topologies and inventories. Service topology in [RFC8345] includes the a virtual topology for a service layer above the L1, L2, and L3 layers. This virtual 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 service topology is mapped onto a subset of nodes from the common L3 topology. In [RFC8299], the 3 types of VPN service topologies proposed for L3VPN service data model are any to any, hub and spoke, hub and spoke disjoint. These VPN topology types can be used to describe how VPN sites are communicating with each other. This document defines a YANG Model for VPN Service Performance Monitoring that can be used to monitor and manage network Performance Wang, et al. Expires April 25, 2019 [Page 2] Internet-Draft Service Topo YANG October 2018 between VPN sites and it is an augmentation to the I2RS network topology YANG data model. 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. The following notations are used within the data tree and carry the meaning as below. Each node is printed as: is one of: + for current is one of: rw for configuration data ro for non-configuration data -x for rpcs -n for notifications -w for writable is the name of the node If the node is augmented into the tree from another module, its name is printed as :. is one of: ? for an optional leaf or choice ! for a presence container * for a leaf-list or list [] for a list's keys (choice)/:(case) Parentheses enclose choice and case nodes, and case nodes are also marked with a colon (":") is the name of the type for leafs and leaf-lists Wang, et al. Expires April 25, 2019 [Page 3] Internet-Draft Service Topo YANG October 2018 3. VPN Service Topology Overview As specified in [RFC8345], the data model defined in [RFC8345] can describe vertical layering relationships between networks that can be augmented to cover network/service topologies. The following figure describes relationships between L3VPN Service Topo and Underlying network: VPN-1 VPN-2 / \ L3VPN-Service-topology 1 L3VPN-Service-topology-2 / | \ / | \ Site-1A site-1B site1-C site-2A Site-2B Site-2C Top-Down | | | | | | Service Topo CE CE CE CE CE CE | | | | | | PE PE PE PE PE PE ====|==========|=======|=======|=========|=====|=================== +-------+ | \ / / | Bottoms-up | | \ / / | Network | | /\ / | topology | | / \ | | | | | | | | node1 node2 node3 node4 node5 node6 layering relationships between L3VPN Service Topo and Underlying network As shown in figure 1, the Site-1,A,B,C are mapped to node 1,2,3 while Site-2 A,B,C are mapped to node 4,5,6 in the underlying physical network. In this figure, an L3SM has two VPN services topologies with 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 L3VPN service topology 1 is hub and spoke topology while L3VPN service topology 2 is hub and spoke disjoint topology. In L3VPN service topology1, Site-1 A plays the role of hub while Site-2 B and C plays the role of spoke. In L3VPN service topoogy2, Site-2 A and B play the role of hub while Site-2 C plays the role of spoke. Wang, et al. Expires April 25, 2019 [Page 4] Internet-Draft Service Topo YANG October 2018 4. VPN service assurance model This module describes VPN Service assurance that can be used to monitor and manage network Performance between VPN sites and it is a augmentation to the I2RS network topology YANG data model. The performance monitoring data is augmented to service topology. +------------+ +---------------------+ |I2RS Network| | VPN Service | |Topo Model |<---------|Peformance Monitoring| +------------+ augments | Model | +---------------------+ 5. Model Usage Guideline An SP must be able to manage the capabilities and characteristics of their VPN services when 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 2, 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 VPN service such as end to end network performance data 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 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 VPN service performance data they are interested in, at the data source. The data source can then use VPN service assurance model and push model [I-D.ietf-netconf-yang-push] to publish specific telemetry data to target recipients. Wang, et al. Expires April 25, 2019 [Page 5] Internet-Draft Service Topo YANG October 2018 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-vpn-svc-pm", which has the following structure 6.1. Network Level module: ietf-vpn-svc-pm augment /nw:networks/nw:network/nw:network-types: +--rw svc-topo-type? identityref augment /nw:networks/nw:network: +--rw svc-topo-attributes +--rw vpn-topo? identityref Network Level View of the hierarchies The VPN service performance monitoring model defines only the following minimal set of Network level service topology attributes: o svc-topo-type: Indicate the network type is service topology type such as L3VPN service topology, L2VPN service topology. o vpn-topo: The type of VPN service topology, Ourproposed model supports any-to-any, Hub and Spoke (where Hubs can exchange traffic), and "Hub and Spoke disjoint" (where Hubs cannot exchange traffic). 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 VPN service performance monitoring model defines only the following minimal set of Node level service topology attributes and constraints: Wang, et al. Expires April 25, 2019 [Page 6] Internet-Draft Service Topo YANG October 2018 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. 6.3. Link and Termination Point Level augment /nw:networks/nw:network/nt:link: +--ro svc-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 Link and Termination point Level View of the hierarchies The VPN service performance monitoring model defines only the following minimal set of Link level service topology attributes: Loss Statistics: A set of loss statistics attributes that are used to measure end to end loss between VPN sites. Delay Statistics: A set of delay statistics attributes that are used to measure end to end latency between VPN sites. Jitter Statistics: A set of jitter statistics attributes that are used to measure end to end jitter between VPN sites. Wang, et al. Expires April 25, 2019 [Page 7] Internet-Draft Service Topo YANG October 2018 7. Example of I2RS Pub/Sub Retrieval This example shows the way for a client to subscribe for the Performance monitoring information for VPN service between VPN sites. The performance monitoring parameter that the client is interested in is end to end loss attribute. vpn1 A pe B pe A-B A B 500 Wang, et al. Expires April 25, 2019 [Page 8] Internet-Draft Service Topo YANG October 2018 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 VPN1. vpn1 A pe B pe A-B A B 9. VPN Service Assurance YANG Module file "ietf-vpn-svc-pm.yang" module ietf-vpn-svc-pm { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-vpn-svc-pm"; prefix svc-topo; import ietf-network { prefix nw; } import ietf-network-topology { prefix nt; Wang, et al. Expires April 25, 2019 [Page 9] Internet-Draft Service Topo YANG October 2018 } import ietf-l3vpn-svc { prefix l3vpn-svc; } organization "IETF xxx Working Group"; contact "Zitao Wang: wangzitao@huawei.com Qin Wu: bill.wu@huawei.com"; description "This module defines a model for the service topology."; revision 2018-08-29 { description "Initial revision."; reference "foo"; } identity service-type { description "Base type for service topology"; } identity l3vpn-svc { base service-type; description "Indentity for layer3 vpn service"; } identity l2vpn-svc { base service-type; description "Identity for layer2 vpn service"; } identity node-type { description "Base identity for node type"; } identity pe { base node-type; description "Identity for PE type"; } identity ce { base node-type; Wang, et al. Expires April 25, 2019 [Page 10] Internet-Draft Service Topo YANG October 2018 description "Identity for CE type"; } identity asbr { base node-type; description "Identity for ASBR type"; } identity p { base node-type; description "Identity for P type"; } 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."; } grouping link-error-statistics { description "Grouping for per link error statistics"; container loss-statistics { description Wang, et al. Expires April 25, 2019 [Page 11] Internet-Draft Service Topo YANG October 2018 "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 { type uint32 { range "0..4294967295"; } description "Total received out of sequence count. Wang, et al. Expires April 25, 2019 [Page 12] Internet-Draft Service Topo YANG October 2018 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."; } leaf max-delay-value { type uint32; description "Maximum delay value observed."; } Wang, et al. Expires April 25, 2019 [Page 13] Internet-Draft Service Topo YANG October 2018 leaf average-delay-value { type uint32; description "Average delay value observed."; } } } 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 value observed."; } } } augment "/nw:networks/nw:network/nw:network-types" { description "Augment the network-types with service topologyies types"; leaf svc-topo-type { type identityref { Wang, et al. Expires April 25, 2019 [Page 14] Internet-Draft Service Topo YANG October 2018 base service-type; } description "Identify the topology type to be composited service topology"; } } augment "/nw:networks/nw:network" { description "Augment the network with service topology attributes"; container svc-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 serice 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 "Role of the site in the IP VPN."; } description "Container for service topology attributes"; } Wang, et al. Expires April 25, 2019 [Page 15] Internet-Draft Service Topo YANG October 2018 } augment "/nw:networks/nw:network/nt:link" { description "Augment the network topology link with vpn service attributes"; container svc-telemetry-attributes { config false; uses link-error-statistics; uses link-delay-statistics; uses link-jitter-statistics; description "Container for service telemetry attributes"; } } } 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 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 /ni:network-instances/ni:network-instance/svc-topo:svc-telemetry- attributes Wang, et al. Expires April 25, 2019 [Page 16] Internet-Draft Service Topo YANG October 2018 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-vpn-svc-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-vpn-svc-pm Namespace: urn:ietf:params:xml:ns:yang:ietf-vpn-svc-pm Prefix: vnrsc Reference: RFC xxxx --------------------------------------------------------------------- 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, . [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation Element (PCE) Communication Protocol (PCEP)", RFC 5440, DOI 10.17487/RFC5440, March 2009, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [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, . Wang, et al. Expires April 25, 2019 [Page 17] Internet-Draft Service Topo YANG October 2018 [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, . [RFC6370] Bocci, M., Swallow, G., and E. Gray, "MPLS Transport Profile (MPLS-TP) Identifiers", RFC 6370, DOI 10.17487/RFC6370, September 2011, . [RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay Measurement for MPLS Networks", RFC 6374, DOI 10.17487/RFC6374, September 2011, . [RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration Protocol (NETCONF) Access Control Model", RFC 6536, DOI 10.17487/RFC6536, March 2012, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC7952] Lhotka, L., "Defining and Using Metadata with YANG", RFC 7952, DOI 10.17487/RFC7952, August 2016, . [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, . Authors' Addresses Michael Wang Huawei Technologies,Co.,Ltd 101 Software Avenue, Yuhua District Nanjing 210012 China Email: wangzitao@huawei.com Wang, et al. Expires April 25, 2019 [Page 18] Internet-Draft Service Topo YANG October 2018 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 Bin Wen Comcast Email: bin_wen@comcast.com Wang, et al. Expires April 25, 2019 [Page 19]