Network Working Group X. Liu Internet-Draft Jabil Intended status: Standards Track I. Bryskin Expires: August 24, 2018 Huawei Technologies V. Beeram Juniper Networks T. Saad Cisco Systems Inc H. Shah Ciena S. Litkowski Orange Business Service February 20, 2018 YANG Data Model for SR and SR TE Topologies draft-ietf-teas-yang-sr-te-topo-00 Abstract This document defines a YANG data model for Segment Routing (SR) topology and Segment Routing (SR) traffic engineering (TE) topology. 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 http://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 August 24, 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 (http://trustee.ietf.org/license-info) in effect on the date of Liu, et al. Expires August 24, 2018 [Page 1] Internet-Draft YANG SR TE Topology February 2018 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 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 2 2. Modeling Considerations . . . . . . . . . . . . . . . . . . . 3 2.1. Segment Routing (SR) topology . . . . . . . . . . . . . . 3 2.2. Segment Routing (SR) TE topology . . . . . . . . . . . . 3 2.3. Relations to ietf-segment-routing . . . . . . . . . . . . 4 2.4. Open Items . . . . . . . . . . . . . . . . . . . . . . . 4 3. Model Structure . . . . . . . . . . . . . . . . . . . . . . . 4 4. YANG Module . . . . . . . . . . . . . . . . . . . . . . . . . 6 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 6. Security Considerations . . . . . . . . . . . . . . . . . . . 11 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 7.1. Normative References . . . . . . . . . . . . . . . . . . 11 7.2. Informative References . . . . . . . . . . . . . . . . . 12 Appendix A. Companion YANG Model for Non-NMDA Compliant Implementations . . . . . . . . . . . . . . . . . . 13 A.1. SR Topology State Module . . . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 1. Introduction This document defines a YANG [RFC7950] data model for describing the presentations of Segment Routing (SR) topology and Segment Routing (SR) traffic engineering (TE) topology. 1.1. Terminology The keywords "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]. The following terms are defined in [RFC7950] and are not redefined here: o augment o data model Liu, et al. Expires August 24, 2018 [Page 2] Internet-Draft YANG SR TE Topology February 2018 o data node 2. Modeling Considerations 2.1. Segment Routing (SR) topology The Layer 3 network topology model is discussed in [I-D.ietf-i2rs-yang-l3-topology]. The Segment Routing (SR) topology model proposed in this document augments and uses the ietf-l3- unicast-igp-topology module defined in [I-D.ietf-i2rs-yang-l3-topology]. SR related attributes are covered in the ietf-sr-topology model. +------------------------------+ | Layer 3 Network Topology | | ietf-l3-unicast-topology | +------------------------------+ | | | V +------------------------+ | SR Topology | | ietf-sr-topology | +------------------------+ 2.2. Segment Routing (SR) TE topology When traffic engineering is enabled on an SR topology, there will be associations between objects in SR topologies and objects in TE topologies. An SR TE topology is both an SR topology and a layer 3 TE topology. Multiple inheritance is used to achieve such relations. +------------------+ +---------------------+ | SR Topology | | L3 TE Topology | | ietf-sr-topology | | ietf-l3-te-topology | +------------------+ +---------------------+ \ / \ / \ / v v +------------------------+ | SR TE Topology | | | +------------------------+ Liu, et al. Expires August 24, 2018 [Page 3] Internet-Draft YANG SR TE Topology February 2018 Each type of topologies is indicated by "network-types" defined in [I-D.ietf-i2rs-yang-network-topo]. For the three types of topologies above, the data representations are: L3 Topology: /nd:networks/nd:network/nd:network-types/l3-unicast-topology L3 TE Topology: /nd:networks/nd:network/nd:network-types/l3-unicast-topology/l3-te SR Topology: /nd:networks/nd:network/nd:network-types/l3-unicast-topology/sr SR TE Topology: (multiple inheritance) /nd:networks/nd:network/nd:network-types/l3-unicast-topology/l3-te /nd:networks/nd:network/nd:network-types/l3-unicast-topology/sr 2.3. Relations to ietf-segment-routing [I-D.ietf-spring-sr-yang]defines ietf-segment-routing that is a model intended to be used on network elements to configure or operate segment routing; ietf-sr-topology defined in this document is intended to be used on a controller for the network-wide operations such as path computation. SR topology model shares many modeling constructs defined in ietf- segment-routing. The module ietf-sr-topology uses the types and groupings defined in ietf-segment-routing. 2.4. Open Items a. Protection on link: The feature of link protection will be modeled in the next revision. b. Link bundle: The feature of link bundle will be modeled in the next revision. 3. Model Structure The model tree structure of the Segment Routing (SR) topology module is as shown below: Liu, et al. Expires August 24, 2018 [Page 4] Internet-Draft YANG SR TE Topology February 2018 module: ietf-sr-topology augment /nw:networks/nw:network/nw:network-types /l3t:l3-unicast-topology: +--rw sr! augment /nw:networks/nw:network/l3t:l3-topology-attributes: +--rw sr +--rw srgb* [lower-bound upper-bound] +--rw lower-bound uint32 +--rw upper-bound uint32 augment /nw:networks/nw:network/nw:node/l3t:l3-node-attributes: +--rw sr +--rw srgb* [lower-bound upper-bound] | +--rw lower-bound uint32 | +--rw upper-bound uint32 +--rw srlb* [lower-bound upper-bound] | +--rw lower-bound uint32 | +--rw upper-bound uint32 +--rw node-capabilities | +--rw transport-planes* [transport-plane] | | +--rw transport-plane identityref | +--rw readable-label-stack-depth? uint8 +--ro information-source? enumeration +--ro information-source-state +--ro credibility-preference? uint16 augment /nw:networks/nw:network/nw:node/l3t:l3-node-attributes /l3t:prefix: +--rw sr! +--rw value-type? enumeration +--rw start-sid uint32 +--rw range? uint32 +--rw algorithm? identityref +--rw last-hop-behavior? enumeration {sid-last-hop-behavior}? +--rw is-local? boolean augment /nw:networks/nw:network/nw:node/nt:termination-point /l3t:l3-termination-point-attributes: augment /nw:networks/nw:network/nt:link/l3t:l3-link-attributes: +--rw sr +--rw sid? uint32 +--rw value-type? enumeration +--rw is-local? boolean +--ro is-part-of-set? boolean +--ro is-on-lan? boolean +--ro information-source? enumeration +--ro information-source-state +--ro credibility-preference? uint16 Liu, et al. Expires August 24, 2018 [Page 5] Internet-Draft YANG SR TE Topology February 2018 4. YANG Module file "ietf-sr-topology@2017-10-30.yang" module ietf-sr-topology { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-sr-topology"; prefix "srt"; import ietf-network { prefix "nw"; } import ietf-network-topology { prefix "nt"; } import ietf-l3-unicast-topology { prefix "l3t"; } import ietf-segment-routing-common { prefix "sr-cmn"; } organization "TBD"; contact "TBD"; description "L3 TE Topology model"; revision 2017-10-30 { description "Initial revision"; reference "TBD"; } grouping sr-topology-type { description "Identifies the SR topology type."; container sr { presence "Indiates SR Topology"; description "Its presence identifies the SR topology type."; } } augment "/nw:networks/nw:network/nw:network-types/" + "l3t:l3-unicast-topology" { description "Defines the SR topology type."; uses sr-topology-type; } Liu, et al. Expires August 24, 2018 [Page 6] Internet-Draft YANG SR TE Topology February 2018 augment "/nw:networks/nw:network/l3t:l3-topology-attributes" { when "../nw:network-types/l3t:l3-unicast-topology/sr" { description "Augment only for SR topology."; } description "Augment topology configuration"; uses sr-topology-attributes; } augment "/nw:networks/nw:network/nw:node/l3t:l3-node-attributes" { when "../../nw:network-types/l3t:l3-unicast-topology/sr" { description "Augment only for SR topology."; } description "Augment node configuration."; uses sr-node-attributes; } augment "/nw:networks/nw:network/nw:node/l3t:l3-node-attributes" + "/l3t:prefix" { when "../../../nw:network-types/l3t:l3-unicast-topology/sr" { description "Augment only for SR topology."; } description "Augment node prefix."; uses sr-node-prefix-attributes; } augment "/nw:networks/nw:network/nw:node/nt:termination-point/" + "l3t:l3-termination-point-attributes" { when "../../../nw:network-types/l3t:l3-unicast-topology/" + "sr" { description "Augment only for SR topology."; } description "Augment termination point configuration"; uses sr-tp-attributes; } augment "/nw:networks/nw:network/nt:link/l3t:l3-link-attributes" { when "../../nw:network-types/l3t:l3-unicast-topology/sr" { description "Augment only for SR topology."; } description "Augment link configuration."; uses sr-link-attributes; } grouping sr-topology-attributes { description "SR topology scope attributes."; container sr { description "Containing SR attributes."; Liu, et al. Expires August 24, 2018 [Page 7] Internet-Draft YANG SR TE Topology February 2018 uses sr-cmn:srgb-cfg; } // sr } // sr-topology-attributes grouping information-source-attributes { description "The attributes identifying source that has provided the related information, and the source credibility."; leaf information-source { type enumeration { enum "unknown" { description "The source is unknown."; } enum "locally-configured" { description "Configured entity."; } enum "ospfv2" { description "OSPFv2."; } enum "ospfv3" { description "OSPFv3."; } enum "isis" { description "ISIS."; } enum "system-processed" { description "System processed entity."; } enum "other" { description "Other source."; } } config false; description "Indicates the source of the information."; } container information-source-state { config false; description "The container contains state attributes related to the information source."; leaf credibility-preference { type uint16; description "The preference value to calculate the traffic engineering database credibility value used for tie-break selection between different information-source values. Liu, et al. Expires August 24, 2018 [Page 8] Internet-Draft YANG SR TE Topology February 2018 Higher value is more preferable."; } } } // information-source-attributes grouping sr-node-attributes { description "SR node scope attributes."; container sr { description "Containing SR attributes."; uses sr-cmn:srgb-cfg; uses sr-cmn:srlb-cfg; uses sr-cmn:node-capabilities; // Operational state data uses information-source-attributes; } // sr } // sr-node-attributes grouping sr-node-prefix-attributes { description "Containing SR attributes for a prefix."; container sr { presence "Presence indicates SR is enabled."; description "Containing SR attributes for a prefix."; uses sr-cmn:prefix-sid-attributes; uses sr-cmn:last-hop-behavior; leaf is-local { type boolean; description "'true' if the SID is local."; } } // sr } // sr-node-prefix-attributes grouping sr-tp-attributes { description "SR termination point scope attributes"; } // sr-tp-attributes grouping sr-link-attributes { description "SR link scope attributes"; container sr { description "Containing SR attributes."; leaf sid { type uint32; description "SID."; } Liu, et al. Expires August 24, 2018 [Page 9] Internet-Draft YANG SR TE Topology February 2018 uses sr-cmn:sid-value-type; leaf is-local { type boolean; description "'true' if the SID is local."; } leaf is-part-of-set { type boolean; config false; description "'true' if the SID is part of a set."; } leaf is-on-lan { type boolean; config false; description "'true' if on a lan."; } uses information-source-attributes; } // sr } // sr-link-attributes } 5. IANA Considerations RFC Ed.: In this section, replace all occurrences of 'XXXX' with the actual RFC number (and remove this note). This document registers the following namespace URIs in the IETF XML registry [RFC3688]: -------------------------------------------------------------------- URI: urn:ietf:params:xml:ns:yang:ietf-sr-topology Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. -------------------------------------------------------------------- -------------------------------------------------------------------- URI: urn:ietf:params:xml:ns:yang:ietf-sr-topology-state Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. -------------------------------------------------------------------- This document registers the following YANG modules in the YANG Module Names registry [RFC6020]: Liu, et al. Expires August 24, 2018 [Page 10] Internet-Draft YANG SR TE Topology February 2018 -------------------------------------------------------------------- name: ietf-sr-topology namespace: urn:ietf:params:xml:ns:yang:ietf-sr-topology prefix: srt reference: RFC XXXX -------------------------------------------------------------------- -------------------------------------------------------------------- name: ietf-sr-topology-state namespace: urn:ietf:params:xml:ns:yang:ietf-sr-topology-state prefix: srt-s reference: RFC XXXX -------------------------------------------------------------------- 6. Security Considerations The configuration, state, action and notification data defined in this document are designed to be accessed via the NETCONF protocol [RFC6241]. The data-model by itself does not create any security implications. The security considerations for the NETCONF protocol are applicable. The NETCONF protocol used for sending the data supports authentication and encryption. 7. References 7.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [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, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [I-D.ietf-netmod-revised-datastores] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., and R. Wilton, "Network Management Datastore Architecture", draft-ietf-netmod-revised-datastores-10 (work in progress), January 2018. Liu, et al. Expires August 24, 2018 [Page 11] Internet-Draft YANG SR TE Topology February 2018 7.2. Informative References [I-D.ietf-i2rs-yang-network-topo] Clemm, A., Medved, J., Varga, R., Bahadur, N., Ananthakrishnan, H., and X. Liu, "A Data Model for Network Topologies", draft-ietf-i2rs-yang-network-topo-20 (work in progress), December 2017. [I-D.ietf-i2rs-yang-l3-topology] Clemm, A., Medved, J., Varga, R., Liu, X., Ananthakrishnan, H., and N. Bahadur, "A YANG Data Model for Layer 3 Topologies", draft-ietf-i2rs-yang- l3-topology-16 (work in progress), December 2017. [I-D.ietf-teas-yang-te-topo] Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and O. Dios, "YANG Data Model for Traffic Engineering (TE) Topologies", draft-ietf-teas-yang-te-topo-13 (work in progress), October 2017. [I-D.ietf-spring-sr-yang] Litkowski, S., Qu, Y., Sarkar, P., and J. Tantsura, "YANG Data Model for Segment Routing", draft-ietf-spring-sr- yang-08 (work in progress), December 2017. Liu, et al. Expires August 24, 2018 [Page 12] Internet-Draft YANG SR TE Topology February 2018 Appendix A. Companion YANG Model for Non-NMDA Compliant Implementations The YANG module ietf-sr-topology defined in this document is designed to be used in conjunction with implementations that support the Network Management Datastore Architecture (NMDA) defined in [I-D.ietf-netmod-revised-datastores]. In order to allow implementations to use the model even in cases when NMDA is not supported, the following companion module, ietf-sr-topology-state, is defined as state model, which mirrors the module ietf-sr-topology defined earlier in this document. However, all data nodes in the companion module are non-configurable, to represent the applied configuration or the derived operational states. The companion module, ietf-sr-topology-state, is redundant and SHOULD NOT be supported by implementations that support NMDA. As the structure of the companion module mirrors that of the coorespinding NMDA model, the YANG tree of the companion module is not depicted separately. A.1. SR Topology State Module file "ietf-sr-topology-state@2017-10-30.yang" module ietf-sr-topology-state { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-sr-topology-state"; prefix "srt-s"; import ietf-sr-topology { prefix "srt"; } import ietf-network-state { prefix "nw-s"; } import ietf-network-topology-state { prefix "nt-s"; } import ietf-l3-unicast-topology-state { prefix "l3t-s"; } import ietf-segment-routing-common { prefix "sr-cmn"; } organization "TBD"; contact "TBD"; description "L3 TE Topology model"; Liu, et al. Expires August 24, 2018 [Page 13] Internet-Draft YANG SR TE Topology February 2018 revision 2017-10-30 { description "Initial revision"; reference "TBD"; } augment "/nw-s:networks/nw-s:network/nw-s:network-types/" + "l3t-s:l3-unicast-topology" { description "Defines the SR topology type."; uses srt:sr-topology-type; } augment "/nw-s:networks/nw-s:network/" + "l3t-s:l3-topology-attributes" { when "../nw-s:network-types/l3t-s:l3-unicast-topology/sr" { description "Augment only for SR topology."; } description "Augment topology configuration"; uses srt:sr-topology-attributes; } augment "/nw-s:networks/nw-s:network/nw-s:node/" + "l3t-s:l3-node-attributes" { when "../../nw-s:network-types/l3t-s:l3-unicast-topology/sr" { description "Augment only for SR topology."; } description "Augment node configuration."; uses srt:sr-node-attributes; } augment "/nw-s:networks/nw-s:network/nw-s:node/" + "l3t-s:l3-node-attributes/l3t-s:prefix" { when "../../../nw-s:network-types/l3t-s:l3-unicast-topology/sr" { description "Augment only for SR topology."; } description "Augment node prefix."; uses srt:sr-node-prefix-attributes; } augment "/nw-s:networks/nw-s:network/nw-s:node/" + "nt-s:termination-point/" + "l3t-s:l3-termination-point-attributes" { when "../../../nw-s:network-types/l3t-s:l3-unicast-topology/" + "sr" { description "Augment only for SR topology."; } description "Augment termination point configuration"; uses srt:sr-tp-attributes; Liu, et al. Expires August 24, 2018 [Page 14] Internet-Draft YANG SR TE Topology February 2018 } augment "/nw-s:networks/nw-s:network/nt-s:link/" + "l3t-s:l3-link-attributes" { when "../../nw-s:network-types/l3t-s:l3-unicast-topology/sr" { description "Augment only for SR topology."; } description "Augment link configuration."; uses srt:sr-link-attributes; } grouping sr-topology-attributes { description "SR topology scope attributes."; container sr { description "Containing SR attributes."; uses sr-cmn:srgb-cfg; } // sr } // sr-topology-attributes } Authors' Addresses Xufeng Liu Jabil 8281 Greensboro Drive, Suite 200 McLean VA 22102 USA EMail: Xufeng_Liu@jabil.com Igor Bryskin Huawei Technologies EMail: Igor.Bryskin@huawei.com Vishnu Pavan Beeram Juniper Networks EMail: vbeeram@juniper.net Liu, et al. Expires August 24, 2018 [Page 15] Internet-Draft YANG SR TE Topology February 2018 Tarek Saad Cisco Systems Inc EMail: tsaad@cisco.com Himanshu Shah Ciena EMail: hshah@ciena.com Stephane Litkowski Orange Business Service EMail: stephane.litkowski@orange.com Liu, et al. Expires August 24, 2018 [Page 16]