i2rs Y. Zhuang, Ed.
Internet-Draft D. Shi
Intended status: Informational Huawei
Expires: May 4, 2017 October 31, 2016

YANG Data Model for Fabric Service delivery in Data Center Network
draft-zhuang-i2rs-dc-fabric-service-model-00

Abstract

This document defines a YANG data model that can be used to deliver fabric service for data center networks. This model is intended to be instantiated by management system to deploy the overall fabric service for a data center network. It provides an abstraction of fabric services, including configurations and functions, however is not a configuration model be used directly onto network infrastructures. It should be used combined with such as fabric topology data model defined in [I-D.zhuang-i2rs-yang-dc-fabric-network-topology] with specific topology information to configure the network elements and deliver the service to data center infrastructures.

Status of This Memo

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This Internet-Draft will expire on May 4, 2017.

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Table of Contents

1. Introduction

Currently, network service provisioning is coupled with specific network topology and technologies applied, which is technology oriented and more device oriented, that makes the network management and application deployment for users complex and lack of flexibility.

In the area of data center networks, the situation is even worse due to massive network devices involved and various applications developed and deployed by users also known as tenants in a more dynamical way. As such, lack of network abstraction and tightly coupled networks in Data center network makes it hard to deploy high level application centric service requests to physical network infrastructures agilely and flexibly.

With existing network management concept, to deliver services from the upper layer users dynamically over the date center network, the network administrator has to configure and operate all involved devices for each tenant with knowledge of the entire network topology, resources and implemented technologies.

To make the network service provisioning more flexible and easy for network administrators, a bottom-up abstraction of network topology in an application centric perspective is introduced, so as to simplify the network service deployment and management of Data Center Network for tenants.

With this purpose, this document defines a YANG data model for the fabric service by using YANG [RFC6020] [RFC7950] to provide a logical fabric network to define and deploy upper layer network services regardless of the specific topology information and underlay/overlay technologies and involved devices. The configuration and operation onto physical infrastructure will be further processed by the topology manager with topology information and technology information.

This model defines the generic configuration for fabric network services regardless of specific fabric topology information. Besides, this model also provides a set of rpc command for operation. In general, this model can be used to expose the logic network to a network orchestrator to define and deploy requested services for user applications regardless of details of topology and technology information within the DC network, while leaving the topology and technology information and management to other components such as a controller.

The data model includes two main modules:

(a)Module “ietf-fabric-service” defines a module for a logical fabric network from the application centric view for user network service. To do so, it augments general network topology model defined in [I-D.ietf-i2rs-yang-network-topo] with logical components such as logical switches, logical routers as well as logical ports to carry network services requested by upper layer users.

(b)Module “ietf-fabric-endpoint” defines a module for endpoints, which represents hosts that runs applications and generating traffics. The major point of this module is to indicate the attachment points of the endpoint in a logical network as well as in a physical fabric network, so as to build bindings between layers.

Besides, the model “ietf-fabric-topology” defined in [I-D.zhuang-i2rs-yang-dc-fabric-network-topology] with topology and resource as well as technology information is used to work together to implement configurations and operations from the logical fabric network onto the specific fabric infrastructure.

2. Terminology

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].

3. Application centric abstraction for DC fabric networks

To make the network service more application centric and easy for network administrator to deploy and manage services for tenants applications, this section describes an application centric network abstraction for DC fabric networks, according to which the network can be abstracted to a logical network for upper layer services.

3.1. Logical fabric network architecture

From the application centric point of view, hosts of tenants can be considered to connect with other hosts through a switch if they are L2 reachable, alternatively, connect through a router if they are L3 reachable.

As such, a tenant network can be abstracted to a logical network in which logical switches connecting hosts that are L2 reachable and a logical router connecting switches which represents L3 reachable regardless of the detailed topology of involved devices and technology information. The diagram for an abstracted network for a tenant is shown below.

  
                        |C3 - L3 Interconnect
                        |
                        |logical port- external gateway
            +-----------|------------+
         C5 |                        |
      -------     Logical Router     |
            |                        |
            +---|--------------|-----+
                |              |logical port-gateway port
                |              |C2
                |              |
                |              |
    +-----------|----+       +-|--------------+
    |                |       |                | Logical port-Access port
    | Logical Switch |       | Logical Switch ------
    |                |       |                | C4 - L2 Interconnect
    +-|---------|----+       +-|---------|----+
      |         |              |C1       |
      |         |              |         |
+-----|---+  +--|------+  +----|----+  +-|-------+
| Endpoint|  | Endpoint|  | Endpoint|  | Endpoint|
+---------+  +---------+  +---------+  +---------+
    

Figure 1: Diagram of a logical fabric network

As a very initial effort to abstract services for fabric-based DC networks, this draft will focus on the abstraction of network connections which is the basis function for a network, while leaving the other network appliance aside.

3.2. Logical Network components

Within a logical fabric network, there are four major components as depicted in figure 1:

Logical Switch:

Works as a switch within a logical fabric network to provide L2 connections between endpoints or to a router or to external networks. It can be bounded to one or several physical switches.

Logical Router:

Works as a router within a logical fabric network to provide L3 connections between switches or to external networks. It can be bounded to one or several physical routers in the physical networks.

Logical Port:

Provides port function on logical switches or logical routers to connect to other components or external networks.

Endpoint:

Represents tenant hosts which can be a VM for example.

3.3. Connections between the components

There are 5 connections for a logical network. Functions of these connections are as follows:

C1: Endpoint attachment. It is used by an endpoint to connect to a logical switch.

C2: L2 to L3 attachment. Interface between a logical switch and a logical router.

C3: L3 interconnection which connects to a logical router.

C4: L2 interconnection which connects to a logical switch.

C5: Route population.

4. Fabric service model usage

4.1. Usage architecture

According to the idea of abstracted fabric network introduced in section 3, a fabric service model is provided to define tenant/user network services in a more concentrated and intuitive way but leaving details of specific network topology, infrastructures and implemented technologies to the topology layer.

With the logical network information from the orchestrator as well topology information, a topology manager will further parse network services requested by logical networks onto configuration/operations of network elements in the physical layer and distribute these configuration and operations onto involved devices to complete the whole process as shown in Fig.2.

  
                                                                                                                                                                                                        
                          +-------------------+                                                                                                                                         
                          |                   |                                                                                                                                         
                          |   Orchestrator    |                                                                                                                                         
                          |                   |                                                                                                                                         
                          +---------|---------+                                                                                                                                         
                                    |                                                                                                                                                   
                                    | Fabric service data                                                                                                                               
                                    |        model                                                                                                                                      
                                    |                                                                                                                                                   
                          +---------V---------+                                                                                                                                         
                          |                   |                                                                                                                                         
                          | Topology Manager  |   Network Provider                                                                                                                      
                          |                   |                                                                                                                                         
                          +---------|---------+                                                                                                                                         
                                    |                                                                                                                                                   
                                    |                                                                                                                                                   
                                    |Fabric Topology data                                                                                                                               
                                    |        model                                                                                                                                      
         .....................................................                                                                                                                      
                                    |                                                                                                                                                   
                             +------V---------+                                                                                                                                         
                            +----------------+|                                                                                                                                         
                           +----------------+||                                                                                                                                         
                           |                |||        Network                                                                                                                          
                           |    Device      ||+                                                                                                                                         
                           |                |+                                                                                                                                          
                           +----------------+                                                                                                                                           

    

Figure 2: Fabric service Usage architecture

According to the topology architecture stated in [I-D.draft-ietf-i2rs-usecase-reqs-summary], the idea of fabric service model is used to provide network services for applications over a data center network, maybe by an orchestration manager for example. By mapping between elements from layers, the topology manager further deploys requested configurations and operations for applications over the physical fabric infrastructures. This mapping is dynamically generated by hosts of tenants defined as endpoints when being online.

4.2. Multi-Layer relationship

There are three layers in this usage as shown in Fig.3.

The fabric service model is abstracted from fabric topology used as an application-centric interface at the service layer to define tenant networks. It is more focused on the network services regardless of specific network types, topologies, technologies etc al.

While the fabric layer collects and maintains the fabric topology information (including single fabric and multi-fabric connections) and specific technologies for each fabric. According to logical network services and fabric topology information, this layer will configure and operate involved network devices in the physical layer to implement the tenant network services.

The physical network layer is at the bottom and consists of all network devices.

 
                        Logical Network Topology
                            +--------+
                            |   LR   |
                            +-/----\-+              +-----------+
   +-----------+             /      \               |Endpoint 2 ++
 +-+Endpoint 1 +            /        \              +-+---------+|
 | +------|----+           /          \               |          |
 |        |           +---/---+     +--\----+         |          |
 |        +-----------+  LSW1 |     | LSW2  +---------+          |
 |                    +-------+     +-------+                    |
 |                                                               |
 |                                                  Service Layer|
 |'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''|''
 |                                                               |
 |                                                               |
 |                                                               |
 |                                                               |
 |        +----------+                     +----------+          |
 |        |          |         Fabric      |          |          |
 |        | Fabric 1 |        Topology     | Fabric 2 |          |
 |        |          |                     |          |          |
 |        +----------+                     +-*-------*+          |
 |         *       *                        *         *    Fabric|
 |        *         *                      *           *   Layer |
 |'''''''*'''''''''''*''''''''''''''''''''*'''''''''''''*''''''''|'
 |      *             *                  *               *       |
 |     *               *                *                 *      |
 |    *                 *              *                   *     |
 |...*...................*......   ...*.....................*... |
 |  *+--------+ +--------+*   .    .   +--------+ +--------+   . |
 |   |        | |        |    .    .   |        | |        |   . |
 |   |        | |        |    .    .   |        | |        |   . |
 |   ++-+----++ ++-----+++    .    .   ++-+----++ ++-----+++   . |
 |    | |    |   |     ||     .    .    | |    |   |     ||    . |
 |    | +-------------+||     .    .    | +-------------+||    . |
 |    |+--------------++|     .    .    |+--------------++|    . |
 |    ||     |   |    | |     .    .    ||     |   |    | |    . |
 | +--++-+  ++---++  ++-+--+  .    . +--++-+  ++---++  ++-+--+ . |
 | |     |  |     |  |     |  .    . |     |  |     |  |     | . |
 +-+     |  |     |  |     |  .    . |     |  |     |  |     +---+
 . +-----+  +-----+  +-----+  .    . +-----+  +-----+  +-----+ .
 .                                                             .
 .          Fabric  1        Physical      Fabric 2       Physical
 ..........................  Topology ...................   Layer

    

Figure 3: Layer Relationship

The mapping of nodes within these layers is realized by endpoints. An endpoint is instantiated by the orchestrator to indicate the locations of a host both in the logical layer as well as in the physical layer, so as to connect network elements of these three layers and deliver services requested from the logical layer onto the physical infrastructure in a dynamic manner.

5. Design of the data model

5.1. Fabric service module

As explained in previous, network service for tenant network can be abstracted to sets of logical switches, logical routers and logical ports. Upon these logical elements, acl policies and gateway functions can be attached.

The fabric service module is defined by YANG module “ietf-fabric-service”. The module is depicted in the following diagram.

  
 module: ietf-fabric-service
  augment /nw:networks/nw:network/nw:node:
    +--ro lsw-attribute
       +--ro lsw-uuid?     yang:uuid
       +--ro name?         string
       +--ro segment-id?   uint32
       +--ro network?      inet:ip-prefix
       +--ro external?     boolean
       +--ro fabric-acl* [fabric-acl-name]
          +--ro fabric-acl-name    string
  augment /nw:networks/nw:network/nw:node:
    +--ro lr-attribute
       +--ro lr-uuid?      yang:uuid
       +--ro name?         string
       +--ro vrf-ctx?      uint32
       +--ro fabric-acl* [fabric-acl-name]
       |  +--ro fabric-acl-name    string
       +--ro routes
          +--ro route* [destination-prefix]
             +--ro description?          string
             +--ro destination-prefix    inet:ipv4-prefix
             +--ro (next-hop-options)?
                +--:(simple-next-hop)
                   +--ro next-hop?             inet:ipv4-address
                   +--ro outgoing-interface?   nt:tp-id
  augment /nw:networks/nw:network/nw:node/nt:termination-point:
    +--ro lport-attribute
       +--ro lport-uuid?         yang:uuid
       +--ro name?               string
       +--ro port-layer
       |  +--ro layer-1-info
       |  |  +--ro location?   nt:tp-id
       |  +--ro layer-2-info
       |  |  +--ro access-type?      access-type
       |  |  +--ro access-segment?   uint32
       |  +--ro layer-3-info
       |     +--ro ip?               inet:ip-address
       |     +--ro network?          inet:ip-prefix
       |     +--ro mac?              yang:mac-address
       |     +--ro forward-enable?   boolean
       |     +--ro logical-switch?   nw:node-id
       +--ro fabric-acl* [fabric-acl-name]
       |  +--ro fabric-acl-name    string
       +--ro port-function
       |  +--ro (function-type)?
       |     +--:(ip-mapping)
       |        +--ro ip-mapping-entry* [external-ip]
       |           +--ro external-ip    inet:ipv4-address
       |           +--ro internal-ip?   inet:ipv4-address
       +--ro underlayer-ports* [port-ref]
          +--ro port-ref    instance-identifier
    

Figure 4: Fabric Service Module

To provide a logical network topology for DC fabric network, the module augments the original ietf-network and ietf-network-topology modules:

  • New nodes for logical switch and logical router with additional data objects are introduced by augmenting the “node” list of the network module.
  • Termination points for logical ports are augmented with logical port information and its reference to termination ports in the underlay topologies. As stated in section 3, the logical port may act as an access port which will be bounded to some physical port, or else it may be as a service point which connects to internal gateway or external gateway. Besides, it can also be attached with ACL rules.

In addition to the configuration part, the module defines several rpc commands to create and remove logical elements of a logical network, as well as to add and delete functions and policies such as gateway and acl on these logical network elements as shown below.

 
 rpcs:
    +---x create-logical-switch
    |  +---w input
    |  |  +---w fabric-id?   fabric:fabric-id
    |  |  +---w name?        string
    |  |  +---w vni?         int32
    |  |  +---w external?    boolean
    |  +--ro output
    |     +--ro node-id?      nw:node-id
    |     +--ro lsw-uuid?     yang:uuid
    |     +--ro name?         string
    |     +--ro segment-id?   uint32
    |     +--ro network?      inet:ip-prefix
    |     +--ro external?     boolean
    |     +--ro fabric-acl* [fabric-acl-name]
    |        +--ro fabric-acl-name    string
    +---x rm-logical-switch
    |  +---w input
    |     +---w fabric-id?   fabric:fabric-id
    |     +---w node-id?     nw:node-id
    +---x create-logical-router
    |  +---w input
    |  |  +---w fabric-id?   fabric:fabric-id
    |  |  +---w name?        string
    |  +--ro output
    |     +--ro node-id?      nw:node-id
    |     +--ro lr-uuid?      yang:uuid
    |     +--ro name?         string
    |     +--ro vrf-ctx?      uint32
    |     +--ro fabric-acl* [fabric-acl-name]
    |     |  +--ro fabric-acl-name    string
    |     +--ro routes
    |        +--ro route* [destination-prefix]
    |           +--ro description?          string
    |           +--ro destination-prefix    inet:ipv4-prefix
    |           +--ro (next-hop-options)?
    |              +--:(simple-next-hop)
    |                 +--ro next-hop?             inet:ipv4-address
    |                 +--ro outgoing-interface?   nt:tp-id
    +---x rm-logical-router
    |  +---w input
    |     +---w fabric-id?   fabric:fabric-id
    |     +---w node-id?     nw:node-id
    +---x add-static-route
    |  +---w input
    |     +---w fabric-id?   fabric:fabric-id
    |     +---w node-id?     nw:node-id
    |     +---w route* [destination-prefix]
    |        +---w description?          string
    |        +---w destination-prefix    inet:ipv4-prefix
    |        +---w (next-hop-options)?
    |           +--:(simple-next-hop)
    |              +---w next-hop?             inet:ipv4-address
    |              +---w outgoing-interface?   nt:tp-id
    +---x rm-static-route
    |  +---w input
    |     +---w fabric-id?            fabric:fabric-id
    |     +---w node-id?              nw:node-id
    |     +---w destination-prefix*   inet:ipv4-prefix
    +---x clear-static-route
    |  +---w input
    |     +---w fabric-id?   fabric:fabric-id
    |     +---w node-id?     nw:node-id
    +---x create-logical-port
    |  +---w input
    |  |  +---w fabric-id?        fabric:fabric-id
    |  |  +---w name?             string
    |  |  +---w logical-device?   nw:node-id
    |  |  +---w attribute
    |  |     +---w lport-uuid?         yang:uuid
    |  |     +---w name?               string
    |  |     +---w port-layer
    |  |     |  +---w layer-1-info
    |  |     |  |  +---w location?   nt:tp-id
    |  |     |  +---w layer-2-info
    |  |     |  |  +---w access-type?      access-type
    |  |     |  |  +---w access-segment?   uint32
    |  |     |  +---w layer-3-info
    |  |     |     +---w ip?               inet:ip-address
    |  |     |     +---w network?          inet:ip-prefix
    |  |     |     +---w mac?              yang:mac-address
    |  |     |     +---w forward-enable?   boolean
    |  |     |     +---w logical-switch?   nw:node-id
    |  |     +---w fabric-acl* [fabric-acl-name]
    |  |     |  +---w fabric-acl-name    string
    |  |     +---w port-function
    |  |     |  +---w (function-type)?
    |  |     |     +--:(ip-mapping)
    |  |     |        +---w ip-mapping-entry* [external-ip]
    |  |     |           +---w external-ip    inet:ipv4-address
    |  |     |           +---w internal-ip?   inet:ipv4-address
    |  |     +---w underlayer-ports* [port-ref]
    |  |        +---w port-ref    instance-identifier
    |  +--ro output
    |     +--ro tp-id?              nt:tp-id
    |     +--ro lport-uuid?         yang:uuid
    |     +--ro name?               string
    |     +--ro port-layer
    |     |  +--ro layer-1-info
    |     |  |  +--ro location?   nt:tp-id
    |     |  +--ro layer-2-info
    |     |  |  +--ro access-type?      access-type
    |     |  |  +--ro access-segment?   uint32
    |     |  +--ro layer-3-info
    |     |     +--ro ip?               inet:ip-address
    |     |     +--ro network?          inet:ip-prefix
    |     |     +--ro mac?              yang:mac-address
    |     |     +--ro forward-enable?   boolean
    |     |     +--ro logical-switch?   nw:node-id
    |     +--ro fabric-acl* [fabric-acl-name]
    |     |  +--ro fabric-acl-name    string
    |     +--ro port-function
    |     |  +--ro (function-type)?
    |     |     +--:(ip-mapping)
    |     |        +--ro ip-mapping-entry* [external-ip]
    |     |           +--ro external-ip    inet:ipv4-address
    |     |           +--ro internal-ip?   inet:ipv4-address
    |     +--ro underlayer-ports* [port-ref]
    |        +--ro port-ref    instance-identifier
    +---x rm-logical-port
    |  +---w input
    |     +---w fabric-id?        fabric:fabric-id
    |     +---w logical-device?   nw:node-id
    |     +---w tp-id?            nt:tp-id
    +---x create-gateway
    |  +---w input
    |  |  +---w fabric-id?        fabric:fabric-id
    |  |  +---w ip-address?       inet:ip-address
    |  |  +---w network?          inet:ip-prefix
    |  |  +---w logical-router?   nw:node-id
    |  |  +---w logical-switch?   nw:node-id
    |  +--ro output
    |     +--ro tp-id?              nt:tp-id
    |     +--ro lport-uuid?         yang:uuid
    |     +--ro name?               string
    |     +--ro port-layer
    |     |  +--ro layer-1-info
    |     |  |  +--ro location?   nt:tp-id
    |     |  +--ro layer-2-info
    |     |  |  +--ro access-type?      access-type
    |     |  |  +--ro access-segment?   uint32
    |     |  +--ro layer-3-info
    |     |     +--ro ip?               inet:ip-address
    |     |     +--ro network?          inet:ip-prefix
    |     |     +--ro mac?              yang:mac-address
    |     |     +--ro forward-enable?   boolean
    |     |     +--ro logical-switch?   nw:node-id
    |     +--ro fabric-acl* [fabric-acl-name]
    |     |  +--ro fabric-acl-name    string
    |     +--ro port-function
    |     |  +--ro (function-type)?
    |     |     +--:(ip-mapping)
    |     |        +--ro ip-mapping-entry* [external-ip]
    |     |           +--ro external-ip    inet:ipv4-address
    |     |           +--ro internal-ip?   inet:ipv4-address
    |     +--ro underlayer-ports* [port-ref]
    |        +--ro port-ref    instance-identifier
    +---x rm-gateway
    |  +---w input
    |     +---w fabric-id?        fabric:fabric-id
    |     +---w ip-address?       inet:ip-address
    |     +---w logical-router?   nw:node-id
    +---x port-binding-logical-to-fabric
    |  +---w input
    |     +---w fabric-id?        fabric:fabric-id
    |     +---w logical-device?   nw:node-id
    |     +---w logical-port?     nt:tp-id
    |     +---w fabric-port?      nt:tp-id
    +---x port-binding-logical-to-device
    |  +---w input
    |     +---w fabric-id?        fabric:fabric-id
    |     +---w logical-device?   nw:node-id
    |     +---w logical-port?     nt:tp-id
    |     +---w physical-port?    fabrictype:tp-ref
    +---x add-port-function
    |  +---w input
    |     +---w fabric-id?        fabric:fabric-id
    |     +---w logical-device?   nw:node-id
    |     +---w logical-port?     nt:tp-id
    |     +---w port-function
    |        +---w (function-type)?
    |           +--:(ip-mapping)
    |              +---w ip-mapping-entry* [external-ip]
    |                 +---w external-ip    inet:ipv4-address
    |                 +---w internal-ip?   inet:ipv4-address
    +---x add-acl
    |  +---w input
    |     +---w fabric-id?        fabric:fabric-id
    |     +---w logical-device?   nw:node-id
    |     +---w logical-port?     nt:tp-id
    |     +---w acl-name?         string
    +---x del-acl
       +---w input
          +---w fabric-id?        fabric:fabric-id
          +---w logical-device?   nw:node-id
          +---w logical-port?     nt:tp-id
          +---w acl-name?         string
    

Figure 5: Fabric Service Module RPC

5.2. Endpoint module

To represent user attachments points and map logical fabric configurations and operations of applications onto the physical fabric infrastructure, an endpoint is instantiated to represent a host of a user that runs applications.

The fabric endpoint module is defined by YANG module “ietf-fabric-endpoint”. The module is depicted as follows:

 
 module: ietf-fabric-endpoint
    +--ro endpoints
       +--ro endpoint* [endpoint-uuid]
          +--ro endpoint-uuid       yang:uuid
          +--ro own-fabric?         fabric:fabric-id
          +--ro mac-address?        yang:mac-address
          +--ro ip-address?         inet:ip-address
          +--ro gateway?            inet:ip-address
          +--ro public-ip?          inet:ip-address
          +--ro location
          |  +--ro node-ref?         fabrictype:node-ref
          |  +--ro tp-ref?           fabrictype:tp-ref
          |  +--ro access-type?      fabrictype:access-type
          |  +--ro access-segment?   uint32
          +--ro logical-location
             +--ro node-id?   nw:node-id
             +--ro tp-id?     nt:tp-id
    

Figure 6: Fabric endpoint module

By indicating locations of an endpoint in “location” container, the logical network elements such as logical nodes and logical termination points are bounded to the network elements in a specific fabric. Then the network configurations and operations from the logical network together with its belonged fabric topology information will further be distributed onto the bounding/related physical elements by the network topology manager.

Besides, the module defines three rpc commands to register, unregister and locate the endpoint onto both logical network and physical network shown as follows.

 
 rpcs:
    +---x register-endpoint
    |  +---w input
    |  |  +---w fabric-id?          fabric:fabric-id
    |  |  +---w endpoint-uuid?      yang:uuid
    |  |  +---w own-fabric?         fabric:fabric-id
    |  |  +---w mac-address?        yang:mac-address
    |  |  +---w ip-address?         inet:ip-address
    |  |  +---w gateway?            inet:ip-address
    |  |  +---w public-ip?          inet:ip-address
    |  |  +---w location
    |  |  |  +---w node-ref?         fabrictype:node-ref
    |  |  |  +---w tp-ref?           fabrictype:tp-ref
    |  |  |  +---w access-type?      fabrictype:access-type
    |  |  |  +---w access-segment?   uint32
    |  |  +---w logical-location
    |  |     +---w node-id?   nw:node-id
    |  |     +---w tp-id?     nt:tp-id
    |  +--ro output
    |     +--ro endpoint-id?   yang:uuid
    +---x unregister-endpoint
    |  +---w input
    |     +---w fabric-id?   fabric:fabric-id
    |     +---w ids*         yang:uuid
    +---x locate-endpoint
       +---w input
          +---w fabric-id?     fabric:fabric-id
          +---w endpoint-id?   yang:uuid
          +---w location
             +---w node-ref?         fabrictype:node-ref
             +---w tp-ref?           fabrictype:tp-ref
             +---w access-type?      fabrictype:access-type
             +---w access-segment?   uint32 
    

Figure 7: Fabric endpoint module RPC

6. Fabric Service YANG Modules

	
<CODE BEGINS> file "ietf-fabric-types@2016-10-13.yang"
module ietf-fabric-types {

    yang-version 1.1;
    namespace "urn:ietf:params:xml:ns:yang:ietf-fabric-types";
    prefix fabrictypes;

    import ietf-inet-types { prefix "inet"; revision-date "2013-07-15"; }

    import ietf-network-topology { prefix nt;  }
	import ietf-network { prefix nw;  }
	
	import ietf-yang-types { prefix "yang"; revision-date "2013-07-15";}

	organization
    "IETF I2RS (Interface to the Routing System) Working Group";
	
	contact
    "WG Web:    <http://tools.ietf.org/wg/i2rs/ >
     WG List:   <mailto:i2rs@ietf.org>

     WG Chair:  Susan Hares
                <mailto:shares@ndzh.com>

     WG Chair:  Russ White
                <mailto:russ@riw.us>

     Editor:    Yan Zhuang
                <mailto:zhuangyan.zhuang@huawei.com>

     Editor:    Danian Shi
                <mailto:shidanian@huawei.com>";
				
    description
        "This module contains a collection of YANG definitions for Fabric.";

    
    revision "2016-10-13" {
        description
            "Initial revision of faas.";
        reference	"draft-zhuang-i2rs-yang-dc-fabric-network-topology-02 and draft-zhuang-i2rs-dc-fabric-service-model-00";
    }

    identity fabric-type {
                description
                        "base type for fabric networks";
    }

    identity vxlan-fabric {
        base fabric-type;
                description
                        "vxlan fabric";
    }

    identity vlan-fabric {
        base fabric-type;
                description
                        "vlan fabric";
    }

    typedef service-capabilities {
        type enumeration {
            enum ip-mapping {
                                description "NAT";
                        }
            enum acl-redirect{
                                description "acl redirect, which can provide SFC function";
                        }
            enum dynamic-route-exchange{
                                description "dynamic route exchange";
                        }
        }
                description
                        "capability of the device";
    }
    /*
     * Typedefs
     */
    typedef node-ref {
        type instance-identifier;
        description "A reference to a node in topology";
    }

    typedef tp-ref {
        type instance-identifier;
        description "A reference to a termination point in topology";
    }

    typedef link-ref {
                type instance-identifier;
        description "A reference to a link in topology";
    }

    typedef device-role {
        type enumeration {
            enum SPINE {
                description "a spine node";
            }
            enum LEAF {
                description "a leaf node";
            }
            enum BORDER {
                description "a border node";
            }
        }
        default "LEAF";
        description "device role type";
    }

    typedef fabric-port-role {
        type enumeration {
            enum internal {
                description "the port used for devices to access each other.";
            }
            enum external {
                description "the port used for fabric to access outside network.";
            }
            enum access {
                description "the port used for Endpoint to access fabric.";
            }
            enum reserved {
                description " not decided yet. ";
            }
        }
                description "the role of the physical port ";
    }

    typedef fabric-port-type {
        type enumeration {
            enum layer2interface {
                                description "l2 if";
            }
            enum layer3interface {
                                description "l3 if";
            }
            enum layer2Tunnel {
                                description "l2 tunnel";
            }
            enum layer3Tunnel {
                                description "l3 tunnel";
            }
        }
                description
                        "fabric port type";
    }

    typedef underlayer-network-type {
        type enumeration {
            enum VXLAN {
                description "vxlan";
            }
            enum TRILL {
                description "trill";
            }
            enum VLAN {
                description "vlan";
            }
        }
                description "";
    }

    typedef layer2-protocol-type-enum {
        type enumeration {
            enum VLAN{
                                description "vlan";
                        }
            enum VXLAN{
                                description "vxlan";
                        }
            enum TRILL{
                                description "trill";
                        }
            enum NvGRE{
                                description "nvgre";
                        }
        }
                description "";
    }

    typedef access-type {
        type enumeration {
            enum exclusive{
                                description "exclusive";
                        }
            enum vlan{
                                description "vlan";
                        }
        }
        description "";
    }

    grouping fabric-port {
                description
                        "attributes of a fabric port";
        leaf name {
            type string;
                        description "name of the port";
        }
        leaf role {
            type fabric-port-role;
                        description "role of the port in a fabric";
        }
        leaf type {
            type fabric-port-type;
                        description "type of the port";
        }
        leaf device-port {
            type tp-ref;
                        description "the device port it mapped to";
        }
        choice tunnel-option {
                        description "tunnel options";

            case gre {
                 leaf src-ip {
                    type inet:ip-prefix;
                                        description "source address";
                }
                leaf dest-ip {
                    type inet:ip-address;
                                        description "destination address";
                }
            }
        }
    }

    grouping route-group {
                description
                        "route attributes";
        list route {
            key "destination-prefix";
                        description "route list";

            leaf description {
                type string;
                description "Textual description of the route.";
            }
            leaf destination-prefix {
                type inet:ipv4-prefix;
                mandatory true;
                description "IPv4 destination prefix.";
            }
            choice next-hop-options {
                                description "choice of next hop options";
                case simple-next-hop {
                    leaf next-hop {
                        type inet:ipv4-address;
                        description "IPv4 address of the next hop.";
                    }
                    leaf outgoing-interface {
                        type nt:tp-id;
                        description "Name of the outgoing interface.";
                    }
                }
            }
        }
    }

    grouping port-functions {
                description
                        "port functions";

        container port-function {
                        description "port functions";
            choice function-type {
                                description "type of functions";
                case ip-mapping {
                    list ip-mapping-entry {
                                                key "external-ip";
                                                description "list of NAT entry";
                        leaf external-ip {
                            type inet:ipv4-address;
                                                        description "external address";
                        }
                        leaf internal-ip {
                            type inet:ipv4-address;
                                                        description "internal address";
                        }
                    }
                }
            }
        }
    }
    grouping acl-list {
                description "acl list";
        list fabric-acl {
                        key fabric-acl-name;
                        description "fabric acl list";
            leaf fabric-acl-name {
                type string;
                                description "acl name";
            }
        }
    }
	///groupings for logical element
	grouping logical-switch {
		description "grouping attributes for a logical switch.";
		
        leaf lsw-uuid {
            type yang:uuid;
			description "logical switch id";
        }
        leaf name {
            type string;
			description "logical switch name";
        }
        leaf segment-id {
            type uint32;
			description "segement id";
        }
        leaf network {
            type inet:ip-prefix;
			description "subnet";
        }
        leaf external {
            type boolean;
			description "whether its a lsw to external network";
        }
        uses acl-list;
    }

    grouping logical-router {
		description "grouping atttributes for a logical router";
        leaf lr-uuid {
            type yang:uuid;
			description "logical router id";
        }
        leaf name {
            type string;
			description "logical router name";
        }
        leaf vrf-ctx {
            type uint32;
			description "logical router vrf id";
        }

        uses acl-list;

		container routes {
			description "routes";
        	uses route-group;
      	}
    }

    grouping logical-port {
		description "grouping attributes for logical ports";
        leaf lport-uuid {
            type yang:uuid;
			description "logical port id";
        }
        leaf name {
            type string;
			description "logical port name";
        }
        container port-layer {
			description "layer information of the lport";
			
            container layer-1-info {
				description "layer 1 information of the lport";
                leaf location {
                    type nt:tp-id;
					description "L1 tp id";
                }
            }
            container layer-2-info {
				description "layer 2 information of the lport";
                leaf access-type {
                    type access-type;
					description "l2 access type";
                }
                leaf access-segment {
                    type uint32;
					description "access segement";
                }
            }
            container layer-3-info {
				description "layer 3 information of the lport";
                leaf ip {
                    type inet:ip-address;
					description "ip address";
                }
                leaf network {
                    type inet:ip-prefix;
					description "ip prefix";
                }
                leaf mac {
                    type yang:mac-address;
					description "mac address";
                }
                leaf forward-enable {
                    type boolean;
					description "whether enable forward";
                }
                leaf logical-switch {
                    type nw:node-id;
					description "lsw id";
                }
            }
        }

        uses acl-list;
        uses port-functions;

        list underlayer-ports {
            key port-ref;
			description "list of the corresponding underlay ports";
            leaf port-ref {
                type instance-identifier;
				description "port reference";
            }
        }
    }
}
<CODE ENDS>
	
<CODE BEGINS> file "ietf-fabric-service@2016-10-12.yang"
module ietf-fabric-service {

    yang-version 1.1;
    namespace "urn:ietf:params:xml:ns:yang:ietf-fabric-service";
    prefix fabric-services;

    import ietf-network { prefix nw;  }
    import ietf-network-topology { prefix nt;  }
	import ietf-fabric-types { prefix fabrictype; revision-date "2016-10-13"; }
    
	import ietf-inet-types { prefix "inet"; revision-date "2013-07-15"; }
    //import yang-ext { prefix "ext"; revision-date "2013-07-09"; }
    import ietf-fabric-topology { prefix fabric; revision-date "2016-09-29"; }
    //import ietf-access-control-list { prefix acl; revision-date "2016-02-18"; }

    organization
    "IETF I2RS (Interface to the Routing System) Working Group";

        contact
   " WG Web:    <http://tools.ietf.org/wg/i2rs/ >
     WG List:   <mailto:i2rs@ietf.org>

     WG Chair:  Susan Hares
                <mailto:shares@ndzh.com>

     WG Chair:  Russ White
                <mailto:russ@riw.us>

     Editor:    Yan Zhuang
                <mailto:zhuangyan.zhuang@huawei.com>

     Editor:    Danian Shi
                <mailto:shidanian@huawei.com>";

    description
        "This module contains a collection of YANG definitions for Fabric services.
                Copyright (c) 2016 IETF Trust and the persons identified as
                authors of the code.  All rights reserved.

                Redistribution and use in source and binary forms, with or
                without modification, is permitted pursuant to, and subject
                to the license terms contained in, the Simplified BSD License
                set forth in Section 4.c of the IETF Trust's Legal Provisions
                Relating to IETF Documents
                (http://trustee.ietf.org/license-info).

                This version of this YANG module is part of
                draft-zhuang-i2rs-yang-fabric-services;
                see the RFC itself for full legal notices.";

    revision "2016-10-12" {
        description
            "Initial revision of fabric service.";
		reference
			"draft-zhuang-i2rs-yang-fabric-service-00";
    }

    augment "/nw:networks/nw:network/nw:node" {
        description "Augmentation for logic switch nodes provided by fabrices.";

        container lsw-attribute {
            config false;
			description "attributes for logical switches";
            uses fabrictype:logical-switch;
        }
    }

    augment "/nw:networks/nw:network/nw:node" {
        description "Augmentation for logical router nodes provided by fabric services.";

        container lr-attribute {
            config false;
			description "attributes for logical routers";
            uses fabrictype:logical-router;
        }
    }

    augment "/nw:networks/nw:network/nw:node/nt:termination-point" {
        description "Augmentation for logical port provided by fabric services.";
		
        container lport-attribute {
			config false;
			description "attributes for logical ports";
            uses fabrictype:logical-port;
        }
    }

    /**************servic api*******************/
    rpc create-logical-switch {
		description "create a logical switch";
        input {
            leaf fabric-id {
                type fabric:fabric-id;
				description "its belonged fabric id";
            }
            leaf name {
                type string;
				description "lsw name";
            }
            leaf vni {
                type int32;
				description "virtual network identifier.usually it is allocated by fabric itself. ";
            }
            leaf external {
                type boolean;
                default false;
				description "whether it is connected to external network";
            }
        }
        output {
            leaf node-id {
                type nw:node-id;
				description "node id";
            }
            uses fabrictype:logical-switch;
        }
    }

    rpc rm-logical-switch {
		description "remove a logical switch";
        input {
            leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }
            leaf node-id {
                type nw:node-id;
				description "node id";
            }
        }
    }

    rpc create-logical-router {
		description "create a  logical router";
        input {
            leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }
            leaf name {
                type string;
				description "name";
            }
        }
        output {
            leaf node-id {
                type nw:node-id;
				description "node id";
            }
            uses fabrictype:logical-router;
        }
    }

    rpc rm-logical-router {
		description "remove a logical router";
        input {
            leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }
            leaf node-id {
                type nw:node-id;
				description "node id";
            }
        }
    }

    rpc add-static-route {
		description "add static routes";
        input {
            leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }
            leaf node-id {
                type nw:node-id;
				description "node id";
            }
            uses fabrictype:route-group;
        }
    }

    rpc rm-static-route {
		description "remove static route";
        input {
            leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }
            leaf node-id {
                type nw:node-id;
				description "node id";
            }
            leaf-list destination-prefix {
                type inet:ipv4-prefix;
				description "DA";
            }
        }
    }

    rpc clear-static-route {
		description "clear all static route on a node";
        input {
            leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }
            leaf node-id {
                type nw:node-id;
				description "node id";
            }
        }
    }

    rpc create-logical-port {
		description "create a logical port";
        input {
            leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }
            leaf name {
                type string;
				description "name";
            }
            leaf logical-device {
                type nw:node-id;
				description "node id";
            }
            container attribute {
				description "logical port attributes";
                uses fabrictype:logical-port;
            }
        }
        output {
            leaf tp-id {
                type nt:tp-id;
				description "tp id";
            }
            uses fabrictype:logical-port;
        }
    }

    rpc rm-logical-port {
		description "remove a logical port";
        input {
            leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }
            leaf logical-device {
                type nw:node-id;
				description "node id";
            }
            leaf tp-id {
                type nt:tp-id;
				description "tp id";
            }
        }
    }

    rpc create-gateway {
		description "create a gateway";
        input {
            leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }
            leaf ip-address {
                type inet:ip-address;
				description "ip addr";
            }
            leaf network {
                type inet:ip-prefix;
				description "ip prefix";
            }
            leaf logical-router {
                type nw:node-id;
				description "lr id";
            }
            leaf logical-switch {
                type nw:node-id;
				description "lsw id";
            }
        }
        output {
            leaf tp-id {
                type nt:tp-id;
				description "port id";
            }
            uses fabrictype:logical-port;
        }
    }

    rpc rm-gateway {
		description "remove gateway";
        input {
            leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }
            leaf ip-address {
                type inet:ip-address;
				description "ip addr";
            }
            leaf logical-router {
                type nw:node-id;
				description "lr id";
            }
        }
    }

    rpc port-binding-logical-to-fabric {
		description "binding logical device to a fabric";
        input {
            leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }
            leaf logical-device {
                type nw:node-id;
				description "node id";
            }
            leaf logical-port {
                type nt:tp-id;
				description "port id";
            }
            leaf fabric-port {
                type nt:tp-id;
				description "port id";
            }
        }
    }

    rpc port-binding-logical-to-device {
		description "binding a logical port on a logical device to a physical device and port";
        input {
            leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }
            leaf logical-device {
                type nw:node-id;
				description "node id";
            }
            leaf logical-port {
                type nt:tp-id;
				description "logical port id";
            }
            leaf physical-port {
                type fabrictype:tp-ref;
				description "physical port ref";
            }
        }
    }

    rpc add-port-function {
		description "add port function to a port";
        input {
            leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }
            leaf logical-device {
                type nw:node-id;
				description "node id";
            }
            leaf logical-port {
                type nt:tp-id;
				description "logical port id";
            }
            uses fabrictype:port-functions;
        }
    }

    rpc add-acl {
		description "add acl";
        input {
            leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }
            leaf logical-device {
                type nw:node-id;
				description "logical device id";
            }
            leaf logical-port {
                type nt:tp-id;
				description "logical port id";
            }
            leaf acl-name {
                type string;
				description "acl name";
            }
        }
    }

    rpc del-acl {
		description "delete acl";
        input {
            leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }
            leaf logical-device {
                type nw:node-id;
				description "logical device id";
            }
            leaf logical-port {
                type nt:tp-id;
				description "logical port id";
            }
            leaf acl-name {
                type string;
				description "acl name";
            }
        }
    }
}
<CODE ENDS>
	
<CODE BEGINS> file "ietf-fabric-endpoint@2016-10-12.yang"
module ietf-fabric-endpoint {

    yang-version 1.1;
    namespace "urn:ietf:params:xml:ns:yang:ietf-fabric-endpoint";
    prefix fabric-endpoints;

    import ietf-inet-types { prefix "inet"; revision-date "2013-07-15"; }
    import ietf-yang-types { prefix "yang"; revision-date "2013-07-15"; }
    import ietf-network { prefix nw;  }
    import ietf-network-topology { prefix nt;  }
	import ietf-fabric-types { prefix fabrictype; revision-date "2016-10-13"; }
	import ietf-fabric-topology { prefix fabric; revision-date "2016-09-29"; }
    
	organization
    "IETF I2RS (Interface to the Routing System) Working Group";
	
	contact
    "WG Web:    <http://tools.ietf.org/wg/i2rs/ >
     WG List:   <mailto:i2rs@ietf.org>

     WG Chair:  Susan Hares
                <mailto:shares@ndzh.com>

     WG Chair:  Russ White
                <mailto:russ@riw.us>

     Editor:    Yan Zhuang
                <mailto:zhuangyan.zhuang@huawei.com>

     Editor:    Danian Shi
                <mailto:shidanian@huawei.com>";

	
    description
        "This module contains a collection of YANG definitions for endpoints in Fabric service.
		
		Copyright (c) 2016 IETF Trust and the persons identified as
		authors of the code.  All rights reserved.

		Redistribution and use in source and binary forms, with or
		without modification, is permitted pursuant to, and subject
		to the license terms contained in, the Simplified BSD License
		set forth in Section 4.c of the IETF Trust's Legal Provisions
		Relating to IETF Documents
		(http://trustee.ietf.org/license-info).

		This version of this YANG module is part of
		draft-zhuang-i2rs-yang-dc-fabric-network-topology;
		see the RFC itself for full legal notices.";

    revision "2016-10-12" {
        description
            "Initial revision of faas.";
		reference
			"draft-zhuang-i2rs-yang-fabric-service-00";
    }

    grouping device-location {
        description "the location for this endponits in the physical network.";

        leaf node-ref {
            type fabrictype:node-ref;
			description "node reference";
        }

        leaf tp-ref {
            type fabrictype:tp-ref;
			description "port reference";
        }

        leaf access-type {
            type fabrictype:access-type;
            default "exclusive";
			description "access type";
        }

        leaf access-segment {
            type uint32;
            default 0;
			description "access segement";
        }
    }

    grouping endpoint-attributes {
		description "endpoint attributes";
		
        leaf endpoint-uuid {
            type yang:uuid;
			description "endpoint id";
        }

        leaf own-fabric {
            type fabric:fabric-id; 
			description "fabric id";
        }

        leaf mac-address {
            type yang:mac-address;
			description "mac addr";
        }

        leaf ip-address {
            type inet:ip-address;
			description "ip addr";
        }

        leaf gateway {
            type inet:ip-address;
			description "gateway ip";
        }

        leaf public-ip {
            type inet:ip-address;
			description "public ip addr";
        }

        container location {
			description "physical location of the endpoint";
            uses device-location;
        }

        container logical-location {
            description "The location for this endpoint in the logical network.";

            leaf node-id {
                type nw:node-id;
				description "node id";
            }

            leaf tp-id {
                type nt:tp-id;
				description "port id";
            }
        }
    }

    container endpoints {
		config false;
        description "endpoints registry for faas.";

        list endpoint {
            key "endpoint-uuid";
			description "endpoint list";
            
			uses endpoint-attributes;
        }
    }

    /********************RPC***************************************/
    rpc register-endpoint {
        description
            "Register a new endpoing into the registry.";

        input {
           leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }

            uses endpoint-attributes;
        }
        output {
            leaf endpoint-id {
                type yang:uuid;
				description "endpoint id";
            }
        }
    }

    rpc unregister-endpoint {
        description "Unregister an endpoint or endpoints from the registry.";
        input {
           leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }

            leaf-list ids {
                type yang:uuid;
				description "a list of ids";
            }
        }
    }

    rpc locate-endpoint {
        description "Set the physical location of the endpoing.";
        input {
           leaf fabric-id {
                type fabric:fabric-id;
				description "fabric id";
            }

            leaf endpoint-id {
                type yang:uuid;
				description "endpoint id";
            }
            container location {
			description "locations";
                uses device-location;
            }
        }
    }
}
<CODE ENDS>
	

7. Security Considerations

None.

8. IANA Considerations

None.

9. References

9.1. Normative References

[I-D.ietf-i2rs-yang-network-topo] Clemm, A., Medved, J., Varga, R., Tkacik, T., Bahadur, N., Ananthakrishnan, H. and X. Liu, "A Data Model for Network Topologies", Internet-Draft draft-ietf-i2rs-yang-network-topo-06, September 2016.
[I-D.zhuang-i2rs-yang-dc-fabric-network-topology] Zhuangyan, Z., Shi, D. and R. Gu, "A YANG Data Model for Fabric Topology in Data Center Network", Internet-Draft draft-zhuang-i2rs-yang-dc-fabric-network-topology-01, September 2016.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997.
[RFC2234] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, DOI 10.17487/RFC2234, November 1997.
[RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010.
[RFC6991] Schoenwaelder, J., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013.
[RFC7950] Bjorklund, M., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016.

9.2. Informative References

[I-D.ietf-i2rs-usecase-reqs-summary] Hares, S. and M. Chen, "Summary of I2RS Use Case Requirements", Internet-Draft draft-ietf-i2rs-usecase-reqs-summary-02, March 2016.

Authors' Addresses

Yan Zhuang (editor) Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China EMail: zhuangyan.zhuang@huawei.com
Danian Shi Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China EMail: shidanian@huawei.com