A YANG Data Model for Layer 1 Network Topology
draft-zhang-i2rs-l1-topo-yang-model-00

I2RS Working Group                                           Xian Zhang 
Internet-Draft                                              Baoquan Rao 
Intended status: Standards Track                                 Huawei 
 
 
Expires: August 13, 2015                             February 12, 2015 
                                      

                                     
             A YANG Data Model for Layer 1 Network Topology 
                                      
                draft-zhang-i2rs-l1-topo-yang-model-00.txt 

Abstract 

   This draft describes a YANG data model to manipulate the topologies 
   of a layer 1 network. It is independent of data plan technologies 
   and control plane protocols. It can be augmented to include 
   technology-specific data, such as for Optical Transport Networks 
   (OTN). 

Status of this Memo 

   This Internet-Draft is submitted to IETF 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 
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   as reference   material or to cite them other than as "work in 
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   The list of current Internet-Drafts can be accessed at   
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   The list of Internet-Draft Shadow Directories can be accessed at   
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   This Internet-Draft will expire on August 13, 2015. 

   Copyright Notice 

   Copyright (c) 2015 IETF Trust and the persons identified as the    
   document authors.  All rights reserved. 

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   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 
   2. Conventions used in this document............................ 3 
   3. Terminology and Notations.................................... 3 
   4. YANG Data Model for Layer 1 Topology .........................3 
      4.1. YANG Tree ............................................. 3 
         4.1.1. Notification.......................................5 
      4.2. YANG Code ............................................. 5 
   5. Security Considerations..................................... 18 
   6. Manageability Considerations................................ 18 
   7. IANA Considerations ........................................ 18 
   8. Acknowledgements ........................................... 18 
   9. References ................................................. 18 
      9.1. Normative References.................................. 18 
      9.2. Informative References................................ 19 
   10. Contributors' Addresses.................................... 19 
   11. Authors' Addresses .........................................19 
    
    

1. Introduction 

   This document defines a data model of a layer one network topology, 
   using YANG [RFC6020]. The model can be used by an application via 
   the I2RS interface [draft-ietf-i2rs-architecture], in the following 
   ways (but not limited to):  

     o to obtain a whole view of the network topology information of 
   its interest;  

      o to receive notifications with regard to the information of the 
   change of the network topology of its interest; 

      o to enforce the establishment/update of a network topology with 
   the characteristic specified in the data model; 

 
 
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   This model is confined to describe layer 1 networks, but it is data 
   plane technology independent and can be augmented to specify the 
   topology for networks such as Optical Transport networks (OTN), 
   Synchronous Digital Network/ (SDH/SONET).  

   [Editor's Note: The authors are aware that there are other drafts 
   closely relating to this draft. Coordination works have been 
   undergoing to get these drafts aligned. ]  

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 RFC-2119 [RFC2119]. 

3. Terminology and Notations 

   A simplified graphical representation of the data model is used in 
   this document. The meaning of the symbols in the YANG data tree 
   presented later in this draft is defined in [ietf-netmod-rfc6087bis]. 
   They are provided below for reference. 

     o  Brackets "[" and "]" enclose list keys. 

      o  Abbreviations before data node names: "rw" means configuration      
   (read-write) and "ro" state data (read-only). 

      o  Symbols after data node names: "?" means an optional node, "!"      
   means a presence container, and "*" denotes a list and leaf-list. 

      o  Parentheses enclose choice and case nodes, and case nodes are 
   also marked with a colon (":"). 

      o  Ellipsis ("...") stands for contents of subtrees that are not      
   shown. 

4. YANG Data Model for Layer 1 Topology 

4.1. YANG Tree  

   module: layer-one-topology 
      +--rw layer-one-topology 
         +--rw topology* [topology-id] 
            +--rw topology-id            topology-id 
            +--rw name?                  string 
            +--rw supporting-topology* [topo-ref] 
 
 
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            |  +--rw topo-ref    leafref 
            +--rw node* [node-id] 
            |  +--rw node-id                node-id 
            |  +--rw interface* [interface-id] 
            |  |  +--rw interface-id             interface-id 
            |  |  +--rw adaptation-capability! 
            |  +--rw connectivity-matrix* [id] 
            |     +--rw id               uint32 
            |     +--rw type?            enumeration 
            |     +--rw in-interface* [interface-ref] 
            |     |  +--rw interface-ref    leafref 
            |     +--rw out-interface* [interface-ref] 
            |     |  +--rw interface-ref    leafref 
            |     +--rw dir?             enumeration 
            +--rw link* [link-id] 
               +--rw link-id            link-id 
               +--rw local 
               |  +--rw local-node?        leafref 
               |  +--rw local-interface?   leafref 
               +--rw remote 
               |  +--rw remote-node?        leafref 
               |  +--rw remote-interface?   leafref 
               +--rw supporting-path* [supporting-path-index] 
               |  +--rw supporting-path-index     uint32 
               |  +--rw topo-ref?                 leafref 
               |  +--rw server-path-identifier! 
               |  +--rw server-path-srlg 
               |     +--rw srlg-values* [srlg-value] 
               |        +--rw srlg-value    uint32 
               +--rw te-attributes 
                  +--rw link-index?                       uint64 
                  +--ro information-source?               enumeration 
                  +--ro credibility-preference?           uint16 
                  +--rw admin-status?                     enumeration 
                  +--ro oper-status?                      enumeration 
                  +--rw area-id?                          binary 
                  +--rw max-link-bandwidth?               decimal64 
                  +--rw unreserved-bandwidth* [priority] 
                  |  +--rw priority     uint8 
                  |  +--rw bandwidth?   decimal64 
                  +--ro distance?                         uint32 
 
 
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                  +--rw te-default-metric?                uint32 
                  +--rw link-protection-type?             enumeration 
                  +--rw interface-switching-capability* [switching-
   capability] 
                  |  +--rw switching-capability switching-capabilities 
                  |  +--rw encoding? encoding-types 
                  |  +--rw max-lsp-bandwidth* [priority] 
                  |  |  +--rw priority     uint8 
                  |  |  +--rw bandwidth?   decimal64 
                  |  +--rw switching-capability-specific-information! 
                  +--rw srlg 
                     +--rw srlg-values* [srlg-value] 
                        +--rw srlg-value    uint32 
4.1.1. Notification 

   [TBD] 

4.2. YANG Code  

   <CODE BEGINS> 

   module layer-one-topology { 
     yang-version 1; 
    
     namespace "urn:ietf:params:xml:ns:yang:layer-one-topology"; 
     prefix l1topo; 
    
     import ietf-inet-types {  
     prefix inet;  
     } 
    
     organization "Internet Engineering Task Force (IETF) I2RS WG"; 
     contact 
       "ID-draft editor: zhang.xian@huawei.com"; 
     description 
       "This module defines a data-plan technology/protocol independent 
   Layer One topology data model."; 
    
     revision 2015-02-11 { 
       description 
         "Initial version"; 
          
       reference 
        "TBD: draft-zhang-i2rs-l1-topo-yang-model-00.txt"; 
     } 
 
 
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     /* 
      * Typedefs 
      */ 
       
     typedef topology-id { 
       type inet:uri; 
     } 
    
     typedef node-id { 
       type inet:ip-address; 
     } 
    
     typedef interface-id { 
       type union {  
          type inet:ip-address; // IPv4 or IPv6 address 
          type int32;          // Unnumbered   
       }  
       description 
       "the identifier of an interface within a node, supporting both 
   numbered/unumbered"; 
     } 
    
     typedef link-id { 
      type inet:ip-address; // IPv4 or IPv6 address  
       description 
       "the identifier of a link"; 
     } 
      
     typedef switching-capabilities {    
       type enumeration {  
         enum "psc-1" {          
           value 1;  
           description  
             "Packet-Switch Capable-1 (PSC-1)";  
         }  
         enum "evpl" {  
           value 30;  
           description  
             "Ethernet Virtual Private Line (EVPL)";  
         }  
          
         enum "pbb-te"{ 
         value 40; 
         description 
           "802_1 PBB-TE"; 
         } 
 
 
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         enum "l2sc" {  
           value 51;  
           description  
             "Layer-2 Switch Capable (L2SC)";  
         }  
         enum "tdm" {  
           value 100;  
           description  
             "Time-Division-Multiplex Capable (TDM)";  
         }  
         enum "otn-tdm" {  
           value 110;  
           description  
             "OTN-TDM Capable";  
         }  
         enum "lsc" {  
           value 150;  
           description  
             "Lambda-Switch Capable (LSC)";  
         }  
         enum "fsc" {  
           value 200;  
           description  
             "Fiber-Switch Capable (FSC)";  
         }  
       }  
        
       description 
        "Switching capability of an interface.  
        Only a subset of the above-mentioned values are applicable to 
   Layer 1 network. Here it is included for completeness and will later 
   be updated if a base model is augmented to create layer 1 network 
   topology YANG data model."; 
        
       reference 
        "The definition of switching types, their values and the 
   relevant RFCs (i.e., RFC3471, 4328) can be found at: 
        http://www.iana.org/assignments/gmpls-sig-parameters/gmpls-
   sig-parameters.xhtml#gmpls-sig-parameters-3"; 
     }  
         
     typedef encoding-types {  
       type enumeration {  
         enum "packet" {          
           value 1;  
           description  
 
 
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             "Packet";  
         }  
         enum "ethernet" {          
           value 2;  
           description  
              "Ethernet";  
         }  
         enum "pdh" {          
           value 3;  
           description  
             "PDH";  
         }  
         enum "sdh-sonet" {          
           value 5;  
           description  
             "SDH/SONET";  
         }  
         enum "digital-wrapper" {          
           value 7;  
           description  
             "Digital Wrapper";  
         }  
         enum "lambda" {          
           value 8;  
           description  
             "Lambda(photonic)";  
         }  
         enum "fiber" {          
           value 9;  
           description  
             "Fiber";  
         }  
         enum "fiber-channel" {          
           value 11;  
           description  
             "FiberChannel";  
         }  
         enum "oduk" {          
           value 12;  
           description  
             "G.709 OKUk (Digital Path)";  
         }  
         enum "optical-channel" {          
           value 13;  
           description  
             "G.709 Optical Channel";  
         }  
 
 
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         enum "line" {          
           value 14;  
           description  
             "Line (e.g., 8B/10B)";  
         } 
       }  
       description  
         "The encoding type supported by an interface or link.  
          Not all encoding types are applicable to Layer one network 
   nodes. They are included here for completeness and will be updated 
   if a base model is available to augment so as to build a layer-one 
   specific YANG data model.";  
       reference 
        "The definition of encoding types, their values and the 
   relevant RFCs (RFC3471, RFC4328, RFC6004) can be found at 
   http://www.iana.org/assignments/gmpls-sig-parameters/gmpls-sig-
   parameters.xhtml#gmpls-sig-parameters-3"; 
     } 
      
     /* 
      * Groupings 
      */ 
       
     grouping srlg-attribute {  
       description  
         "Shared Risk Link Group Attributes";  
       reference  
         "RFC 4203: OSPF Extensions in Support of Generalized Multi-
   Protocol Label Switching (GMPLS)";  
       list srlg-values {  
         key "srlg-value";  
         leaf srlg-value {  
           type uint32;  
         }  
       }  
     }  
    
     /* 
      * Configuration data nodes 
      */ 
    
    
     container layer-one-topology { 
       list topology { 
         key "topology-id"; 
         leaf topology-id { 
           type topology-id; 
 
 
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         } 
      
         leaf name { 
           type string; 
         } 
      
         list supporting-topology { 
           key "topo-ref"; 
           leaf topo-ref { 
             type leafref { 
               path "/layer-one-topology/topology/topology-id"; 
             } 
           description 
            "a Layer-One network might be supported by a lower layer 
   network and this is a pointer to the suporting topology if there is 
   one"; 
           } 
         } 
          
         list node { 
           key "node-id"; 
           leaf node-id { 
             type node-id; 
           } 
           list interface { 
             key "interface-id"; 
             leaf interface-id { 
               type interface-id; 
             } 
             container adaptation-capability { 
               presence "to define adaptation capability for different 
   technologies."; 
              description 
                "TBD"; 
             } 
           } 
           list connectivity-matrix { 
             key "id"; 
              
             description 
              "This describes the connectivity contraints within a 
   node in the network. It can  be one matrix or a set of matrixes. 
   Further details, read the reference provided below."; 
             reference 
               "https://tools.ietf.org/html/draft-ietf-ccamp-general-
   constraint-encode-16 Section 2.1";  
                  
 
 
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             leaf id { 
               type uint32; 
             } 
             leaf type { 
               type enumeration { 
                 enum fixed { 
                   value 0; 
                 } 
                 enum dynamic { 
                   value 1; 
                 } 
               } 
                
               description 
               "This field describes the attribute of a connectivity 
   matrix, i.e., whether it is fixed or switched."; 
             } 
             list in-interface { 
               key "interface-ref"; 
              
             description 
                "This list describes a (sub)-set of ingoing-
   interfaces within a node that may have connectivity constraints. 
              Note: directionality may not be relevant and it is 
   decided by the dir parameter."; 
                
               leaf interface-ref {             
               type leafref { 
                   path "/layer-one-
   topology/topology/node/interface/interface-id"; 
                 } 
               } 
             } 
             list out-interface { 
               key "interface-ref"; 
              
             description 
              "This list describes a (sub)-set of ingoing-
   interfaces within a node that may have connectivity constraints. 
              Note: directionality may not be relevant and it is 
   decided by the dir parameter."; 
               
               leaf interface-ref { 
                 type leafref { 
                   path "/layer-one-
   topology/topology/node/interface/interface-id"; 
                 } 
 
 
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               } 
             } 
             leaf dir{ 
               type enumeration{ 
               enum "uni-dir"{ 
                 description 
                   "the matrix is unidirectional."; 
               } 
               enum "bi-dir"{ 
                 description 
                   "this matrix is bidirecdtional."; 
               } 
               } 
             } 
           } 
         } 
       
         list link { 
         key "link-id"; 
         leaf link-id { 
             type link-id; 
             description 
               "remaining issue: if there is no IP addresses 
   associated with this link,  
               what would be the key?"; 
         } 
          
           container local { 
            leaf local-node { 
              type leafref { 
               path "/l1topo:layer-one-topology/topology/node/node-id"; 
              } 
            } 
            leaf local-interface { 
              type leafref { 
               path "/l1topo:layer-one-
   topology/topology/node/interface/interface-id"; 
              } 
            } 
         } 
         container remote { 
            leaf remote-node { 
              type leafref { 
                 path "/l1topo:layer-one-topology/topology/node/node-
   id"; 
              } 
            } 
 
 
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            leaf remote-interface { 
              type leafref { 
               path "/l1topo:layer-one-
   topology/topology/node/interface/interface-id"; 
              } 
            } 
         } 
         list supporting-path { 
            key "supporting-path-index"; 
            leaf supporting-path-index { 
              type uint32; 
            } 
            leaf topo-ref { 
              type leafref { 
               path "/l1topo:layer-one-topology/topology/topology-id"; 
              } 
            } 
            container server-path-identifier { 
              presence "Define server path identifier."; 
            } 
            container server-path-srlg { 
              uses srlg-attribute; 
            } 
         } 
          
         container te-attributes { 
            leaf link-index { 
              type uint64; 
            } 
            leaf information-source { 
             type enumeration {  
               enum "unknown" {  
                 description  
                  "The source is unknown";  
               }  
               enum "locally-configured" {  
                 description  
                  "Configured TE link";  
               }  
               enum "ospfv2" {  
                 description  
                  "OSPFv2";  
               }  
               enum "ospfv3" {  
                 description  
                  "OSPFv3";  
               }  
 
 
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               enum "isis" {  
                 description  
                  "ISIS";  
               }  
              } 
              config false;  
               
              description   
               "Indicates the source of the information about the link. 
                remaining issue: if configuration of a link is allowed, 
   what additional types are needed to add?";  
            } 
            leaf credibility-preference { 
              type uint16; 
              config false; 
            } 
            leaf admin-status {  
              type enumeration {  
                enum up {  
                 value 1;  
                 description  
                   "up";  
               }  
               enum down {  
                 value 2;  
                 description  
                   "down";  
               }  
               enum testing {  
                 value 3;  
                 description  
                   "testing - in some test mode.";  
               }  
             }  
             description  
               "The adminstrative state of the link.";  
             reference 
              "RFC2863: The Interfaces Group MIB."; 
           }  
           leaf oper-status {  
             type enumeration {  
               enum up {  
                 value 1;  
                 description  
                   "up";  
               }  
               enum down {  
 
 
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                 value 2;  
                 description  
                   "down";  
               }  
               enum testing {  
                 value 3;  
                 description  
                   "testing - in some test mode";  
               }  
               enum unknown {  
                 value 4;  
                 description  
                   "unknown - status cannot be determined for some 
   reason.";  
               } 
               enum dormant{ 
                 value 5; 
               } 
             }  
             config false; 
             description  
               "The current operational state of the link.";  
             reference 
              "RFC2863: The Interfaces Group MIB."; 
           }  
           leaf area-id {  
             type binary {  
               length 1..13;  
             }  
             description  
               "This object indicates the area identifier of the IGP, 
   it can identify either a OSPF or ISIS area.";  
              reference 
              "RFC4920:  Crankback Signaling Extensions for MPLS and 
   GMPLS RSVP-TE."; 
           } 
    
           leaf max-link-bandwidth { 
             type decimal64 { 
               fraction-digits 2; 
             } 
             description 
              "the max bandwidth supported by this link"; 
           } 
    
           list unreserved-bandwidth { 
             key "priority"; 
 
 
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             max-elements "8"; 
              
             description 
              "This describes the unreserved bandwidth (in 
   Bytes/second) on a level basis ( level 0-7)."; 
               
             leaf priority { 
               type uint8{ 
               range "0..7"; 
               } 
             } 
             leaf bandwidth { 
               type decimal64 { 
                 fraction-digits 2; 
               } 
             } 
           } 
            
           leaf distance { 
            type  uint32; 
            units "kilometers"; 
             
            config false; 
            description 
              "the distance this link spans."; 
           } 
           leaf te-default-metric { 
             type uint32; 
           } 
            
           leaf link-protection-type { 
             type enumeration {  
                enum "extra-traffic" {  
                 description "Extra traffic";  
               }  
                enum "unprotected" {  
                 description "unprotected";  
               }  
               enum "shared" {  
                 description "Shared";  
               }  
               enum "1-for-1" {  
                 description "Dedicated one for one protection";  
               }  
               enum "1-plus-1" {  
                 description "Dedicated one plus one protection";  
               }  
 
 
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               enum "enhanced" {  
                 description "a protection type that is more reliable 
   than Dedicated 1-plus-1, e.g., 4 fiber BLSR/MS-SPRING.";  
               }  
             }  
             description  
               "Link Protection Type configured for this link"; 
             reference 
              "RFC3471: Generalized MUlti-Protocol Label Switching 
   (GMPLS) Signaling Functional Description.";  
           } 
           list interface-Switching-capability { 
             key "switching-capability"; 
             leaf switching-capability { 
               type switching-capabilities; 
             } 
             leaf encoding { 
               type encoding-types; 
               description 
                 "the encoding type supported by this link."; 
             } 
             list max-lsp-bandwidth { 
               key "priority"; 
               max-elements "8"; 
               leaf priority { 
                 type uint8 { 
                   range "0..7"; 
                 } 
               } 
               leaf bandwidth {  
                 type decimal64 {  
                   fraction-digits 2; 
                 } 
               } 
               description 
                "remaining issue: to check how is used."; 
             } 
             container switching-capability-specific-information { 
               presence "to define switch capability specific 
   information for technology specific network (e.g., OTN)."; 
             } 
           } 
           container srlg { 
             uses srlg-attribute; 
           } 
         } 
       } 
 
 
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     } 
     }   
   } 
   <CODE ENDS>  

 
5. Security Considerations 

   The YANG data model defined in this draft itself does not introduce 
   additional security concerns besides those mentioned in [draft-ietf-
   i2rs-architecture]. 
    
6. Manageability Considerations  

   TBD. 
    
7. IANA Considerations 

   TBD.  
    
8. Acknowledgements 

   The initial YANG model specified in this draft is based on draft-
   clemm-i2rs-yang-network-topo but it is modified according to the 
   features of the layer one networks.  
    
   [Editor's note: Further modification of this data model will be 
   seeking ways to get aligned by augmenting.] 
    
   We would like to thank the authors of the above mentioned draft, 
   especially Xufeng Liu, for his helpful discussion during the 
   creation of this draft. 
    
9. References 

9.1. Normative References 

   [RFC2119] S. Bradner, "Key words for use in RFCs to indicate 
             requirements levels", RFC 2119, March 1997.  

   [RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the            
             Network Configuration Protocol (NETCONF)", RFC 6020,              
             October 2010. 

 
 
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draft-zhang-i2rs-l1-topo-yang-model-00.txt                February 2015 
    

   [ietf-netmod-rfc6087bis] Bierman, A., "Guidelines for Authors and 
             Reviewers of YANG  Data Model Documents", draft-ietf-
             netmod-rfc6087bis-01, work in progress, October 2014. 

9.2. Informative References 

   [draft-ietf-i2rs-architecture] Atlas, A., Halpern, J., Hares, S., 
             Ward, D., Nadeau T., "An Architecture for the Interface to 
             the Routing System", draft-ietf-i2rs-architecture-08, work 
             in progress, January 2015; 

   [draft-clemm-i2rs-yang-network-topo] Clemm A., Medved J., Tkacik T., 
   Varga R., et al, "A YANG Data Model for Network Topologies", draft-
   clemm-i2rs-yang-network-topo-01, work in progress, October 2014; 

10. Contributors' Addresses 

11. Authors' Addresses 

   Xian Zhang 
   Huawei Technologies 
   Email: zhang.xian@huawei.com
    
   Baoquan Rao 
   Huawei Technologies 
   raobaoquan@huawei.com
    
    

 
 
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