Network Working Group X. Liu Internet-Draft Ericsson Intended status: Standards Track I. Bryskin Expires: January 7, 2017 Huawei Technologies V. Beeram Juniper Networks T. Saad Cisco Systems Inc H. Shah Ciena S. Litkowski Orange Business Service July 7, 2016 YANG Data Model for SR and SR TE Topologies draft-liu-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), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html This Internet-Draft will expire on January 7, 2017. Liu, et al. Expires January 7, 2017 [Page 1] Internet-Draft draft-liu-teas-yang-sr-te-topo-00 July 2016 Copyright Notice Copyright (c) 2016 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 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.........................5 2.4. Open Items................................................5 3. Model Structure................................................5 4. YANG Module....................................................8 5. Security Considerations.......................................16 6. References....................................................16 6.1. Normative References.....................................16 6.2. Informative References...................................17 1. Introduction This document defines a YANG [RFC6020] 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 [RFC6020] and are not redefined here: Liu, et al. Expires January 7, 2016 [Page 2] Internet-Draft draft-liu-teas-yang-sr-te-topo-00 July 2016 o augment o data model o data node 2. Modeling Considerations 2.1. Segment Routing (SR) topology The Layer 3 network topology model is discussed in [YANG-L3-TOPO]. The Segment Routing (SR) topology model proposed in this document augments and uses the ietf-l3-unicast-igp-topology module defined in [YANG-L3-TOPO]. SR related attributes are covered in the ietf-sr- topology model. +------------------------------+ | Layer 3 Network Topology | | ietf-l3-unicast-igp-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. Liu, et al. Expires January 7, 2016 [Page 3] Internet-Draft draft-liu-teas-yang-sr-te-topo-00 July 2016 +------------------+ +---------------------+ | SR Topology | | L3 TE Topology | | ietf-sr-topology | | ietf-l3-te-topology | +------------------+ +---------------------+ \ / \ / \ / v v +------------------------+ | SR TE Topology | | | +------------------------+ Each type of topologies is indicated by "network-types" defined in [YANG-NET-TOPO]. For the three types of topologies above, the data representations are: L3 Topology: /nw:networks/nw:network/nw:network-types/l3-unicast-igp-topology L3 TE Topology: /nw:networks/nw:network/nw:network-types/l3-unicast-igp-topology/l3- te SR Topology: /nw:networks/nw:network/nw:network-types/l3-unicast-igp-topology/sr SR TE Topology: (multiple inheritance) /nw:networks/nw:network/nw:network-types/l3-unicast-igp-topology/l3- te /nw:networks/nw:network/nw:network-types/l3-unicast-igp-topology/sr Liu, et al. Expires January 7, 2016 [Page 4] Internet-Draft draft-liu-teas-yang-sr-te-topo-00 July 2016 2.3. Relations to ietf-segment-routing [YANG-SR] 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) Coordinating changes to [YANG-SR]: Currently some of the SR constructs defined in [YANG-SR] cannot be shared as is. Coordination with the authors of [YANG-SR] is in progress to define the sharable groupings and types, which will also need to be not depending on other device models. b) Protection on link: The feature of link protection will be modeled in the next revision. c) 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: module: ietf-sr-topology augment /nw:networks/nw:network/nw:network-types/l3t:l3-unicast-igp- topology: +--rw sr! augment /nw:networks/nw:network/l3t:igp-topology-attributes: +--rw sr +--rw config +--rw srgb* [lower-bound upper-bound] +--rw lower-bound uint32 +--rw upper-bound uint32 augment /nw:networks/nw:network/nw:node/l3t:igp-node-attributes: +--rw sr +--rw config | +--rw srgb* [lower-bound upper-bound] | | +--rw lower-bound uint32 | | +--rw upper-bound uint32 Liu, et al. Expires January 7, 2016 [Page 5] Internet-Draft draft-liu-teas-yang-sr-te-topo-00 July 2016 | +--rw capabilities | +--rw transport-planes* [transport-plane] | | +--rw transport-plane identityref | +--rw segment-stack-push-limit? uint8 | +--rw readable-label-stack-depth? uint8 +--ro state +--ro information-source? enumeration +--ro information-source-state | +--ro credibility-preference? uint16 +--ro capabilities +--ro transport-planes* [transport-plane] | +--ro transport-plane identityref +--ro segment-stack-push-limit? uint8 +--ro readable-label-stack-depth? uint8 augment /nw:networks/nw:network/nw:node/l3t:igp-node- attributes/l3t:prefix: +--rw sr! +--rw value-type? enumeration +--rw start-sid uint32 +--rw range? uint32 +--rw last-hop-behavior? enumeration {sid-last-hop-behavior}? +--rw is-local? boolean +--rw algorithm? sr-algorithm augment /nw:networks/nw:network/nw:node/nt:termination-point/l3t:igp- termination-point-attributes: augment /nw:networks/nw:network/nt:link/l3t:igp-link-attributes: +--rw sr +--rw config | +--rw sid? uint32 | +--rw value-type? enumeration | +--rw is-local? boolean | +--ro is-part-of-set? boolean | +--ro is-on-lan? boolean +--ro state +--ro information-source? enumeration +--ro information-source-state +--ro credibility-preference? uint16 SR topology module is an augmentation to L3 IGP unicast topology module. When these two modules are put together, the following trees provider better high level pictures: Liu, et al. Expires January 7, 2016 [Page 6] Internet-Draft draft-liu-teas-yang-sr-te-topo-00 July 2016 modules: ietf-l3-unicast-igp-topology, ietf-sr-topology: augment /nw:networks/nw:network: +--rw igp-topology-attributes +--rw name? string +--rw flag* flag-type +--rw srt:sr +--rw srt:config +--rw srt:srgb* [lower-bound upper-bound] +--rw srt:lower-bound uint32 +--rw srt:upper-bound uint32 augment /nw:networks/nw:network/nw:node: +--rw igp-node-attributes +--rw name? inet:domain-name +--rw flag* flag-type +--rw router-id* inet:ip-address +--rw prefix* [prefix] | +--rw prefix inet:ip-prefix | +--rw metric? uint32 | +--rw flag* flag-type | +--rw srt:sr! | +--rw srt:value-type? enumeration | +--rw srt:start-sid uint32 | +--rw srt:range? uint32 | +--rw srt:last-hop-behavior? enumeration {sid-last-hop- behavior}? | +--rw srt:is-local? boolean | +--rw srt:algorithm? sr-algorithm +--rw srt:sr +--rw srt:config | +--rw srt:srgb* [lower-bound upper-bound] | | +--rw srt:lower-bound uint32 | | +--rw srt:upper-bound uint32 | +--rw srt:capabilities | +--rw srt:transport-planes* [transport-plane] | | +--rw srt:transport-plane identityref | +--rw srt:segment-stack-push-limit? uint8 | +--rw srt:readable-label-stack-depth? uint8 +--ro srt:state +--ro srt:information-source? enumeration +--ro srt:information-source-state | +--ro srt:credibility-preference? uint16 Liu, et al. Expires January 7, 2016 [Page 7] Internet-Draft draft-liu-teas-yang-sr-te-topo-00 July 2016 +--ro srt:capabilities +--ro srt:transport-planes* [transport-plane] | +--ro srt:transport-plane identityref +--ro srt:segment-stack-push-limit? uint8 +--ro srt:readable-label-stack-depth? uint8 augment /nw:networks/nw:network/nt:link: +--rw igp-link-attributes +--rw name? string +--rw flag* flag-type +--rw metric? uint32 +--rw srt:sr +--rw srt:config | +--rw srt:sid? uint32 | +--rw srt:value-type? enumeration | +--rw srt:is-local? boolean | +--ro srt:is-part-of-set? boolean | +--ro srt:is-on-lan? boolean +--ro srt:state +--ro srt:information-source? enumeration +--ro srt:information-source-state +--ro srt:credibility-preference? uint16 augment /nw:networks/nw:network/nw:node/nt:termination-point: +--rw igp-termination-point-attributes +--rw (termination-point-type)? +--:(ip) | +--rw ip-address* inet:ip-address +--:(unnumbered) +--rw unnumbered-id? uint32 4. YANG Module file "ietf-sr-topology@2016-06-24.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 { Liu, et al. Expires January 7, 2016 [Page 8] Internet-Draft draft-liu-teas-yang-sr-te-topo-00 July 2016 prefix "nt"; } import ietf-l3-unicast-igp-topology { prefix "l3t"; } import ietf-segment-routing { prefix "sr"; } organization "TBD"; contact "TBD"; description "L3 TE Topology model"; revision "2016-06-24" { description "Initial revision"; reference "TBD"; } typedef sr-algorithm { type enumeration { enum "spf" { description "Shortest Path First."; } enum "strict-spf" { description "Strict Shortest Path First."; } } description "Algorithm to be used for the prefix SID."; } grouping sr-topology-type { description "Identifies the SR topology type."; container sr { presence "Indiates SR Topology"; description "Its presence identifies the SR topology type."; } } Liu, et al. Expires January 7, 2016 [Page 9] Internet-Draft draft-liu-teas-yang-sr-te-topo-00 July 2016 augment "/nw:networks/nw:network/nw:network-types/" + "l3t:l3-unicast-igp-topology" { description "Defines the SR topology type."; uses sr-topology-type; } augment "/nw:networks/nw:network/l3t:igp-topology-attributes" { when "../nw:network-types/l3t:l3-unicast-igp-topology/sr" { description "Augment only for SR topology."; } description "Augment topology configuration"; uses sr-topology-attributes; } augment "/nw:networks/nw:network/nw:node/l3t:igp-node-attributes" { when "../../nw:network-types/l3t:l3-unicast-igp-topology/sr" { description "Augment only for SR topology."; } description "Augment node configuration."; uses sr-node-attributes; } augment "/nw:networks/nw:network/nw:node/l3t:igp-node-attributes" + "/l3t:prefix" { when "../../../nw:network-types/l3t:l3-unicast-igp-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:igp-termination-point-attributes" { when "../../../nw:network-types/l3t:l3-unicast-igp-topology/" + "sr" { description "Augment only for SR topology."; } description "Augment termination point configuration"; uses sr-tp-attributes; Liu, et al. Expires January 7, 2016 [Page 10] Internet-Draft draft-liu-teas-yang-sr-te-topo-00 July 2016 } augment "/nw:networks/nw:network/nt:link/l3t:igp-link-attributes" { when "../../nw:network-types/l3t:l3-unicast-igp-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."; container config { description "Configuraiton attributes."; uses sr: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."; } Liu, et al. Expires January 7, 2016 [Page 11] Internet-Draft draft-liu-teas-yang-sr-te-topo-00 July 2016 enum "isis" { description "ISIS."; } enum "system-processed" { description "System processed entity."; } enum "other" { description "Other source."; } } description "Indicates the source of the information."; } container information-source-state { 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. Higher value is more preferable."; } } } // information-source-attributes grouping sr-node-attributes { description "SR node scope attributes."; container sr { description "Containing SR attributes."; container config { description "Configuraiton attributes."; uses sr:srgb-cfg; uses sr-node-capabilities; } // config container state { Liu, et al. Expires January 7, 2016 [Page 12] Internet-Draft draft-liu-teas-yang-sr-te-topo-00 July 2016 config false; description "Operational state data."; uses information-source-attributes; uses sr-node-capabilities; } } // sr } // sr-node-attributes grouping sr-node-capabilities { description "Containing SR node capabilities."; container capabilities { list transport-planes { key transport-plane; leaf transport-plane { type identityref { base sr:segment-routing-transport; } description "Transport plane supported"; } description "List of supported transport planes."; } leaf segment-stack-push-limit { type uint8; description "Describes the number of segments that can be pushed by the node."; } leaf readable-label-stack-depth { type uint8; description "Number of MPLS labels that can be read in the stack."; } description "Shows the SR capability of the node."; } // capabilities } // sr-node-capabilitie Liu, et al. Expires January 7, 2016 [Page 13] Internet-Draft draft-liu-teas-yang-sr-te-topo-00 July 2016 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:sid-value-type; leaf start-sid { type uint32; mandatory true; description "Value associated with prefix. The value must be interpreted in the context of value-type."; } leaf range { type uint32; description "Describes how many SIDs could be allocated."; } uses sr:last-hop-behavior; leaf is-local { type boolean; description "'true' if the SID is local."; } leaf algorithm { type sr-algorithm; description "Algorithm used."; } } // sr } // sr-node-prefix-attributes grouping sr-tp-attributes { description "SR termination point scope attributes"; } // sr-tp-attributes Liu, et al. Expires January 7, 2016 [Page 14] Internet-Draft draft-liu-teas-yang-sr-te-topo-00 July 2016 grouping sr-link-attributes { description "SR link scope attributes"; container sr { description "Containing SR attributes."; container config { description "Configuraiton attributes."; leaf sid { type uint32; description "SID."; } uses sr: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."; } } container state { config false; description "Operational state data."; uses information-source-attributes; } } // sr } // sr-link-attributes Liu, et al. Expires January 7, 2016 [Page 15] Internet-Draft draft-liu-teas-yang-sr-te-topo-00 July 2016 } 5. 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. 6. References 6.1. Normative References [RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, October 2010. [RFC6021] Schoenwaelder, J., "Common YANG Data Types", RFC 6021, October 2010. [RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J., and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, June 2011. [RFC2234] Crocker, D. and Overell, P.(Editors), "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, Internet Mail Consortium and Demon Internet Ltd., November 1997. [YANG-NET-TOPO]Clemm, A., "A Data Model for Network Topologies", draft-ietf-i2rs-yang-network-topo (Work in Progress). [YANG-L3-TOPO] Clemm, A., et al., "A YANG Data Model for Layer 3 Topologies", draft-ietf-i2rs-yang-l3-topology, (Work in Progress). [YANG-TE-TOPO] Liu, X., et al., "YANG Data Model for TE Topologies", draft-ietf-teas-yang-te-topo, Work in Progress). [YANG-SR] Litkowski, S., et al., "YANG Data Model for Segment Routing", draft-ietf-spring-sr-yang, Work in Progress). Liu, et al. Expires January 7, 2016 [Page 16] Internet-Draft draft-liu-teas-yang-sr-te-topo-00 July 2016 6.2. Informative References [RFC6087] Bierman, A., "Guidelines for Authors and Reviewers of YANG Data Model Documents", RFC 6087, January 2011. Liu, et al. Expires January 7, 2016 [Page 17] Internet-Draft draft-liu-teas-yang-sr-te-topo-00 July 2016 Authors' Addresses Xufeng Liu Ericsson / Kuatro Technologies Inc. 8281 Greensboro Drive, Suite 200 McLean, VA 22102 USA Email: xliu@kuatrotech.com Igor Bryskin Huawei Technologies Email: Igor.Bryskin@huawei.com Vishnu Pavan Beeram Juniper Networks Email: vbeeram@juniper.net 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 January 7, 2016 [Page 18]