I2RS S. Hares
Internet-Draft Hickory Hill Consulting
Intended status: Standards Track L. Dunbar
Expires: January 7, 2016 Huawei
July 6, 2015

A Yang model for I2RS service topology
draft-hares-i2rs-service-topo-dm-00.txt

Abstract

This document defines I2RS protocol-independent service layer virtual topology data model. This data model utilizes the concepts in the generic I2RS topology model of virtual networks (node, links, termination points) and cross-layer topologies. This virtual service topology may be a composite layer created from the combination of protocol-dependent service layers. Protocol-dependent services layers include: L3VPN, L2VPN, EVPN, E-Tree, and others.

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Table of Contents

1. Introduction

Service topology in [I-D.ietf-i2rs-yang-network-topo] 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. The virtual service topology is a network-wide topology stored on one routing system which an I2RS agent is connected to.

The virtual service topology is a composite of the available services topologies IETF has standard virtual network topologies for L3VPN, L2VPN, and EVPN services, E-TREE services, Seamless MPLS topologies within an As and others. This yang module provides the composite protocol independent service topology that these protocol dependent topologies plug into

1.1. 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 [RFC2119].

1.2. Base Model: the Service-Topology Component

            +----------------+
			|    network     | 
            |    topology    |<...
            +----------------+   :
              *           *  :   :
              |           |  :...:
              |           |
      +--------+        +--------+
  ...>|  node  |<.......|link |<...
  :   +--------+<.......+--------+   :
  :    :   *             : :  *  :   :
  :.....   |             : :  |  :...:
           |             : :  |
.....>+--------+<........: :  |
:     |   TP   |<..........:  |
: ...>+--------+              |
: :                           |
: : .....................+---------+
.........................|Direction|
                         +---------+

The following diagram contains an informal graphical depiction of the main elements of the information model:

2. High level Yang architecture

This section describes the Yang High level architecture.

2.1. Network level

The service topology network level defines the following high-level yang architeture:

module: i2rs-service-topologies
   augment /nw:network/nw:network-types:
      +--rw service-topologies-types
   augment /nw:network:
     +--rw service-topology-attributes
         +--rw name?   string
		 +--rw flag	   flag_type;
 		 +--rw composite-flag identity-ref 
		 +--rw service-topo-id network-id
		 +--rw node-count  uint32
		 +--rw composite-flag_status identity-ref 

The service topology attributes for a network include the following

2.2. Node level

module: i2rs-service-topologies
.... 
   augment /nw:network/nw:node
      +--rw node-service-attributes
         +--rw name?        inet:domain-name
         +--rw composite_flag*  identityref;
		 +--rw service-node-id  uint32
		 +--rw node-svc_status* identityref;

The additional fields in the service attributes are the following:

2.3. Service Link and Termination point

   augment /nw:network/nt:link:
      +--rw service-link-attributes
         +--rw name?     string
         +--rw svc-link-type identityref 		 
         +--rw metric?   uint32
   augment /nw:network/nw:node/nt:termination-point:
      +--rw service-termination-point-attributes
	     +--rw tp-svc-id 	
         +--rw (supporting-termination-point) ()
            +--:(service)
			|  +--rw service-network-id  leafref
            |  +--rw service-node-id     leafref
			|  +--rw service-tp-id       leafref
			+--:(ip)
			|  +--rw ip-address   inet:ip-address
            +--:(unnumbered)
               +--rw unnumbered-id?   uint32

The augmentation to the service topology is the service link attributes which include:

The augmentation to the termination point include the following

3. Yang Data Model

 <CODE BEGINS>
   file "i2rs-service-topology@2015-07-07.yang"
   module i2rs-service-topology {
     yang-version 1;
     namespace "urn:ietf:params:xml:ns:yang:i2rs-service-topology";
     prefix "i2rs-st";
     import ietf-network {
       prefix "nw";
     }
     import ietf-network-topology {
       prefix "nt";
     }
     import ietf-inet-types {
       prefix "inet";
     }
     organization "TBD";
     contact "TBD";

     description
       "This module defines a model for the service topology.";

     revision "2015-07-07" {
       description "Initial revision";
       reference "TBD";
     }
	 
	identity svc-topo-flag-identity {
	  description "Base type for svc flags";
	  }
	  
	identity l3vpn-svc-topo {
	  base svc-topo-flag-identity;
	  description "L3VPN service type";
	 }
	 
	identity l2vpn-svc-topo {
	  base svc-topo-flag-identity;
	  description "L2VPN service type";
	 }
	
	 identity EVPN-svc-topo {
	  base svc-topo-flag-identity;
	  description "EVPN service type";
	 }
	 
	  identity Seamless-MPLS-svc-topo {
	  base svc-topo-flag-identity;
	  description "Seamless MPLS service type";
	 }
	 
	  identity Etree-svc-topo {
	  base svc-topo-flag-identity;
	  description "Seamless MPLS service type";
	 }	 
	 
	  identity I2rs-svc-topo {
	  base svc-topo-flag-identity;
	  description "I2RS create service topo";
	 }	 
	 
	identity svc-tp-type {
	  description "Base type for service
       termination-point type flags";
	  } 
	  
	identity svc-tp-type-service {
	  base svc-tp-type;
	  description "service type";
	 }
	identity svc-tp-type-ip {
	  base svc-tp-type;
	  description "service IP";
	 } 
 	identity svc-tp-type-unnum {
		  base svc-tp-type;
	  description "service unnumbered link";
	 } 
	grouping service-topology-types {
	 leaf service-type* {
		type identityref {
		  base svc-topo-flag-identity;
	     }
		 description "list of topology type
		 supported"
		 
	   }
	}
	
	grouping service-topology attributes {
	   description 
	    "Grouping for the attribute for the
		service topology";
		leaf name {type string;
	     	description "name of service 
			topology"};
		leaf composite-flag {
		  type identityref {
		     base service-topology-types;}
		   description "other topologies
		   this topology is configured to
            be a composite of
		   (L3VPN, L2VPN, I2RS only)"
		}
		leaf service-topo-id {
			type leafref {
			 path "/nw:network/nw:network-id"
			 }
			 description
			 "An absolute reference to a network topology instance."
		  }
		 leaf service-id-number {
		    type uint32;
			description "ID for topology";
		}
		leaf node-node {
		   type unint32;
		   description "count of service level nodes
		    in the network."
		  }
		leaf composite-flag-status {
		  type identityref {
		     base svc-topo-flag-identity;}
		   description "other topologies
		   this topology is currently a
            composite of
		   (L3VPN, L2VPN, I2RS only)"
		}
	}
	
	grouping node-svc-attribute {
	    leaf name {
		  type inet:domain-name;
		  description "Domain name for node";
		 }
        leaf composite-flag* {
		  type identityref {
		     base svc-topo-flag-identity;}
		   description "virtual network 
		    node can be composite of the
		   topologies list 
		   (L3VPN, L2VPN, I2RS only)"
		  }
		 leaf service-node-id {
		  type uint32;
		  description "ID for node at
		   service level";
		 }
		 leaf node-svc_status {
		  type identityref {
		     base service-topology-types;}
		   description "other topologies
		   this topology is currewntly 
            be a composite of
		   (L3VPN, L2VPN, I2RS only)"
		} 
	}		 
		 
    grouping service-link-attributes {
	  leaf name {type string; 
	      description "name of 
		  service link";}
	  leaf link-id uint32; 
	  leaf svc-link-type {
	  		  type identityref {
		     base service-topology-types;}
		   description "other topologies
		   this link is current a composite of
		   (L3VPN, L2VPN, I2RS only)"
		}
	  leaf metric {
	      type uint32;
		  description "link metric";
      // may need to expand with TE topologies
		}
	}
 
    grouping service-termination-point-attributes {
	   leaf svc-tp-id {
			type uint32;
			description "termination point id";
	   }
	   container supporting-termination-point {
	    leaf svc-tp-type {
		   type identityref {
		     base svc-tp-type;}
		   description "other topologies
		   this link termination point is
		   part of
		   (L3VPN, L2VPN, I2RS only)"
	    
	     choice svc-tp-type 
		    case svc-tp-type-service {
			 description "network, node,
			  tp that supports this 
			  termination point"
				leaf service-network-id {
				 type uint32; }
				leaf service-node-id {
				  type unit32;}
				leaf service-link-id {
				  type uint32;}
			  }
			  case svc-tp-type-inet {
			   leaf ip-address inet:ip-addresss;
			  }
			  case svc-tp-type-unnum {
			   leaf unnumbered-id {
			     type uint32;}}
			  }
		  } 
	     
	   
	}
 
	   augment /nw:network/nw:node
      +--rw node-svc-attributes
         +--rw name?        inet:domain-name
         +--rw composite_flag*  flag-type
		 +--rw service-node-id  uint32
		 +--rw node-svc-type service-type
		 +--rw next-hop     [next-hop-id]
	
    augment /nw:network/nw:network-types
	  use service-topology-types
    augment /nw:network/nw:network
	  use service-topology-attributes
	  
    augment /nw:network/nw:node
	  use node-svc-attribute
 
    augment /nw:network/nt:link:
      uses service-link-attributes
 
   augment /nw:network/nw:node/nt:termination-point:
      uses service-termination-point-attributes
  } // module i2rs-service-topology
 <CODE BEGINS>

4. IANA Considerations

TBD

5. Security Considerations

TBD

6. Normative References

[I-D.ietf-i2rs-yang-l3-topology] Clemm, A., Medved, J., Varga, R., Tkacik, T., Liu, X., Bryskin, I., Guo, A., Ananthakrishnan, H., Bahadur, N. and V. Beeram, "A YANG Data Model for Layer 3 Topologies", Internet-Draft draft-ietf-i2rs-yang-l3-topology-00, June 2015.
[I-D.ietf-i2rs-yang-network-topo] Clemm, A., Medved, J., Varga, R., Tkacik, T., Bahadur, N. and H. Ananthakrishnan, "A Data Model for Network Topologies", Internet-Draft draft-ietf-i2rs-yang-network-topo-01, June 2015.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC5511] Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax Used to Form Encoding Rules in Various Routing Protocol Specifications", RFC 5511, April 2009.

Authors' Addresses

Susan Hares Hickory Hill Consulting 7453 Hickory Hill Saline, MI 48176 USA EMail: shares@ndzh.com
Linda Dunbar Huawei USA EMail: linda.dunbar@huawei.com