Networking Slicing for 5G with SDN/NFV: Concepts, Architectures, and Challenges

Abstract

Introduction

Network slices:

Through technologies like software-defined networking (SDN) and network functions virtualization (NFV), network softwarization can provide the programmability, flexibility, and modularity that is required to create multiple logical (virtual) networks, each tailored for a given use case, on top of a common network.

The concept of separated virtual networks deployed over a single network is indeed not new (e.g., virtual private networks, VPNs).

We define network slices as end-to-end (E2E) logical networks running on a common underlying (physical or virtual) network, mutually isolated, with independent control and management, which can be created on demand. Such self-contained networks must be flexible enough to simultaneously accommodate diverse business-driven use cases from multiple players on a common network infrastructure.

Background on key concepts for network slicing

Resources

  • Network Functions (NFs)
  • Infrastructure Resources

Virtualization

Orchestration

Isolation

  • Performance
  • Security and privacy
  • Management

Open Network Foundation (ONF) network slicing architecture

SDN architecture:

  • resources
    • infrastructure resources
    • network functions (NFs)
    • network services
  • controllers: a logically centralized entity instantiated in the control plane
    • operates SDN resources at runtime to deliver services in an optimal way

components of an SDN controller:

  • Client context

    • a Resource Group
    • a client support function

  • Server context: assembled in a Resource Group

The SDN architecture also includes an administrator. Its tasks consist of:

  • instantiating and configuring the entire controller
    • the creation of both server and client contexts
    • the installation of their associated policies

NFV reference architectural framework

The NFV architecture:

  • manages the infrastructure resources
  • orchestrates the allocation of such resources need to realize VNFs and network services

Embracing SDN and NFV architectures into a common reference framework is not an easy task.

ETSI integrates SDN within the reference NFV architecture:

  • two SDN controllers
    • one placed at the tenant
    • another at the InP level

Network slicing use case with SDN-NFV integration

Challenges and research directions

Performance issues in a shared infrastructure

Management and orchestration issues

Security and privacy

  • software integrity
  • remote attestation
  • dynamic threat detection and mitigation
  • user authentication
  • accounting management

New business models

Given this business-oriented approach, new transition strategies must be broadly ananlyzed, allowing for a gradual evolution to future 5G networks and ensuring compatibility with past infrastructure investments.

To accomplish this, a deep review of the telecom regulatory framework has to be made.