Network Service Virtual Link

Summary
This input includes following proposals
- Simplified NsVirtualLink Toscal Model.
- Corresponding Group, Policy and node types.
- Possible implementation data models of virtual links
Simplified Network Service Virtual Link model.
Below is the simplified model for the TOSCA which proposes to merge the properties in virtual link descriptor, virtual link deployment flavour and virtual link profiles in to one node type NsVirtualLink.

Following elements are modeled as Data Types

tosca.datatypes.nfv.ConnectivityType

  tosca.datatypes.nfv.ConnectivityType:
    derived_from: tosca.datatypes.Root
    description: virtual link connectivity type
    properties:
      protocol:
        type: list
        required: true
        default: 
		  - ipv4
 		entry_schema:
          constraint: 
            -valid_values: [ethernet, mpls, odu2, ipv4, ipv6, pseudo-wire]
		
      flowPattern:
        type: string
        required: false
        default: line
        constraint: 
          -valid_values: [line, tree, mesh]

tosca.datatypes.nfv.Qos

tosca.datatypes.nfv.Qos:
  derived_from: tosca.datatypes.Root
  description: virtual link quality of service parameters
  properties:
    latency:
      type: float
      description: maximum latency in ms
      required: true
      constraints:
        greater_or_equal: 0
        
    packetDelayVariation:
      type: float
      description: maximum jitter in ms
      required: true

    packetLossRatio:
      type: float
      description: maximum packet loss ratio
      required: false
      constraints:
        greater_or_equal: 0

    priority:
      type: integer
      description: Specifies the priority level in case of congestion on the underlying physical link
      required: false

    bitrateRequired:
      type: tosca.datatypes.nfv.Bitrate
      description: required bitrate
      required: true

    minBitrate:
      type: tosca.datatypes.nfv.Bitrate
      description: min bitrate supported
      required: true

    maxBitrate:
      type: tosca.datatypes.nfv.Bitrate
      description: max bitrate supported
      required: true

tosca.datatypes.nfv.Bitrate

tosca.datatypes.nfv.Bitrate:
  derived_from: tosca.datatypes.Root
  description: link bit rate
  properties:
    root:
      type: float
      description: throughput of the link
      required: true
      constraints:
        greater_or_equal: 0
        
    leaf:
      type: float
      description: throughput of the leaf connection
      required: false
      constraints:
        greater_or_equal: 0

tosca.datatypes.nfv.ServiceAvailability

Groups and policy for Affinity/ Anti-affinity

tosca.grouptypes and tosca.policytypes

Virtual Link Data Modelling
- Virtual links need to be realized on the physical infrastructure based on the topology.
- This means the same virtual ink can be realized with more than one way.
- Followign is a simplified example of two types realizations. So even the wan link can also be realized a specific implementation of the virtual link.
- Proposal
  - Network Service template would specifiy an abstract NsVirtualLink
  - Each implemention can be specified as a separate service template using the substitution mapping.
  - Orchestractor would select the suitable subistituable service template based on the underlying infrastructure.
- - Ns Virtual Iink Node type
    tosca.nodes.nfv.NsVirtualLink
  - Service template with a implemenation of virtual link
    service template
More Information in the attached file