1. Policy-based Orchestration of NFV Services in Software-Defined Networks
Kostas Giotis, Yiannos Kryftis, Vasilis Maglaris
Network Management & Optimal Design Laboratory (NETMODE)
School of Electrical & Computer Engineering
National Technical University of Athens
1st IEEE Conference on Network Softwarization (NetSoft 2015)
April 15th, 2015
London, UK

2. Trends in Telcos Industry
Telco networks demonstrate:
Significant growth of traffic volumes
Increased data rates
Plethora of diverse network services
SDN and NFV architectures promise:
Increased business agility (speed up services deployment)
Decreased operational costs
Decoupling of services from the physical substrate

3. SDN and NFV overlook SDN Protocols NFV Architectures
Multiple SDN protocols (OF, ForCES, Cisco OpFlex)
OF is still dominant
Delivers:
Network programmability
Decouple Data & Control Plane
Listen & Handle Network Events
No standardized protocols
All approaches are based on the ETSI specification
Delivers:
Agile placement of networking services
Service-driven virtual Networks
Optimized usage of COTS Hardware devices

4. Delivery of agile services through SDN and NFV synergies
Motivation
Design Principles
Formulate a baseline architecture to facilitate policy-driven dynamic methods for:
management of SDN resources
lifecycle management of VNFs and the associated data
orchestration of multiple diverse VNFs to deliver Business Applications as NFV Services (i.e. Service Chains)
Modular design that decouples:
Hardware elements
VNFs
Business (NFV) Services
Orchestration
Information Model to uniformly describe network resources and functions
Instantiate and Manage NFV Services, governed by policies

5. Architectural Components
This schema permits:
Selection of VNFs from a VNF Pool
Use Policy-Engines to manipulate VNFs
Combine Diverse VNFs to deliver NFV Services
Physical Infrastructure
Nodes
Controllers
VNF Pool
Diverse VNFs
“Templates”
NFV Services
Business Applications
Service Chains
NFV Orchestrator
Mgmt Functions
Information Model

6. Architectural Components
Physical Infrastructure
Nodes
Controllers
VNF Pool
Diverse VNFs
“Templates”
NFV Services
Business Applications
Service Chains
NFV Orchestrator
Mgmt Functions
Information Model
Policy Engine:
Policy-based management of substrate resources
VNF Lifecycle Management
Orchestration of NFV Services
NFV Services consist of one or more VNFs, and:
Deliver tailor-made Business Applications
Interact with Diverse VNFs
Implement Forwarding Graphs (VNF-FGs)
Uniquely-identified substrate objects:
Managed in an abstracted manner
Agnostic to the actual substrate
Use abstracted physical resources for:
Programmable Network Functions templates
Isolated instances

7. Policy-based NFV Orchestrator
The management environment is divided in three layers
The lower layer concerns policy based management for OF substrate resources, providing management enforcement methods on MOs representing them
The middle layer deals with VNF lifecycle management. All VNF components are represented as MOs and their methods may include policy-based management actions to be executed on lower layer MOs
The higher layer provides policy-based Orchestration of NFV Services. Each NFV Service extends the Managed Object Class and it includes the methods for capturing and creating events, and performing management actions on VNF components in the pool, based on high-level policies

8. Types of Policies
Event-Condition-Action(ECA) Policies: They enforce control and management actions upon certain events within the managed environment, possibly causing reconfiguration of the system
Authorization Policies: They define what actions Users with specific Roles can perform on Target MOs
Role Assignment Policies: They are used to define different classes of Users, receiving different access privileges and usage priority on specific services provided by VNFs

9. Graphical overview of the classes in the Ontology
The Policy Engine residing in the NFV Orchestrator stands for the management environment that encompasses a collection of Managed Objects (MOs) in hierarchical order, representing:
Policies (i.e. Event-Condition-Action (ECA), authorization, role assignment)
OF resources (i.e. Controller, Switch, Link, Port)
VNF components and
NFV services

10. Ponder2 Policy Framework
For the development of VNF Orchestrator’s policy engine, the Ponder2 policy framework was selected:
It supports all aforementioned policy types and it uses user- extensible management objects
It was extended to represent the substrate resources, and the NFV Services as Managed Objects able to be managed by the policies
Conflict Resolution

11. Prototype VNFs Monitoring VNF Network Embedder VNF
Instruct for the acquisition of flow statistics
Statistics are initially collected at the Controller
Flow-stats request/reply event
Capable to interface with different types of monitoring data managers
E.g. sFlow Collector
Map virtual paths to the physical substrate
Upon User request
Create e2e virtual links
Clients are considered to be large scale customers
e.g. content or alternate providers
Do not require significant number of identifiers (we user VLANs)

12. Role-based Traffic Engineering
NFV Service:
Role-based Traffic Engineering
Monitoring and N.E. VNFs are chained to create RbTE instances as a Business Application
Client receives different type and quality of services
2 client tiers in prototype, regarding traffic routing:
Tier 1: path with least utilized links (best effort)
Tier 2: Shortest path – high priority

13. Case Study Traffic Engineering for CDN Caching Nodes
CDN Providers deploy Caching Nodes inside the premises of other operators
CDN Providers are treated as clients
An Operator might host multiple Caching Nodes of different CDN providers

14. Proof-of-concept demonstration
Experimental Results
Proof-of-concept demonstration
Indicative Role-based services functionality
Future Work:
Avoid path switching for Tier 1 clients when the link is not saturated
Integrate a virtualization layer through a network hypervisor (e.g. OpenVirtex) for isolated, Policy-based Control Plane management.

15. Thank you!
Kostas Giotis