1. Introduction

This document represents and describes the results of the OPNFV NetReady (Network Readiness) project. Specifically, the document comprises a selection of NFV-related networking use cases and their networking requirements. For every use case, it furthermore presents a gap analysis of the aforementioned requirements with respect to the current OpenStack networking architecture. Finally it provides a description of potential solutions and improvements.

1.1. Scope

NetReady is a project within the OPNFV initiative. Its focus is on NFV (Network Function Virtualization) related networking use cases and their requirements on the underlying NFVI (Network Function Virtualization Infrastructure).

The NetReady project addresses the OpenStack networking architecture, specifically OpenStack Neutron, from a NFV perspective. Its goal is to identify gaps in the current OpenStack networking architecture with respect to NFV requirements and to propose and evaluate improvements and potential complementary solutions.

1.2. Problem Description

Telco ecosystem’s movement towards the cloud domain results in Network Function Virtualization that is discussed and specified in ETSI NFV. This movement opens up many green field areas which are full of potential growth in both business and technology. This new NFV domain brings new business opportunities and new market segments as well as emerging technologies that are exploratory and experimental in nature, especially in NFV networking.

It is often stated that NFV imposes additional requirements on the networking architecture and feature set of the underlying NFVI beyond those of data center networking. For instance, the NFVI needs to establish and manage connectivity beyond the data center to the WAN (Wide Area Network). Moreover, NFV networking use cases often abstract from L2 connectivity and instead focus on L3-only connectivity. Hence, the NFVI networking architecture needs to be flexible enough to be able to meet the requirements of NFV-related use cases in addition to traditional data center networking.

Traditionally, OpenStack networking, represented typically by the OpenStack Neutron project, targets virtualized data center networking. This comprises originally establishing and managing layer 2 network connectivity among VMs (Virtual Machines). Over the past releases of OpenStack, Neutron has grown to provide an extensive feature set, covering both L2 as well as L3 networking services such as virtual routers, NATing, VPNaaS and BGP VPNs.

It is an ongoing debate how well the current OpenStack networking architecture can meet the additional requirements of NFV networking. Hence, a thorough analysis of NFV networking requirements and their relation to the OpenStack networking architecture is needed.

Besides current additional use cases and requirements of NFV networking, more importantly, because of the green field nature of NFV, it is foreseen that there will be more and more new NFV networking use cases and services, which will bring new business, in near future. The challenges for telco ecosystem are to:

  • Quickly catch the new business opportunity;
  • Execute it in agile way so that we can accelerate the time-to-market and improve the business agility in offering our customers with innovative NFV services.

Therefore, it is critically important for telco ecosystem to quickly develop and deploy new NFV networking APIs on-demand based on market need.

1.3. Goals

The goals of the NetReady project and correspondingly this document are the following:

  • This document comprises a collection of relevant NFV networking use cases and clearly describes their requirements on the NFVI. These requirements are stated independently of a particular implementation, for instance OpenStack Neutron. Instead, requirements are formulated in terms of APIs (Application Programming Interfaces) and data models needed to realize a given NFV use case.
  • The list of use cases is not considered to be all-encompassing but it represents a carefully selected set of use cases that are considered to be relevant at the time of writing. More use cases may be added over time. The authors are very open to suggestions, reviews, clarifications, corrections and feedback in general.
  • This document contains a thorough analysis of the gaps in the current OpenStack networking architecture with respect to the requirements imposed by the selected NFV use cases. To this end, we analyze existing functionality in OpenStack networking.
  • Beyond current list of use cases and gap analysis in the document, more importantly, it is the future of NFV networking that needs to be made easy to innovate, quick to develop, and agile to deploy and operate. A model-driven, extensible framework is expected to achieve agility for innovations in NFV networking.
  • This document will in future revisions describe the proposed improvements and complementary solutions needed to enable OpenStack to fulfill the identified NFV requirements.