Network Function Virtualization: State-of-the-art and Research Challenges (1509.07675v1)

Abstract: Network Function Virtualization (NFV) has drawn significant attention from both industry and academia as an important shift in telecommunication service provisioning. By decoupling Network Functions (NFs) from the physical devices on which they run, NFV has the potential to lead to significant reductions in Operating Expenses (OPEX) and Capital Expenses (CAPEX) and facilitate the deployment of new services with increased agility and faster time-to-value. The NFV paradigm is still in its infancy and there is a large spectrum of opportunities for the research community to develop new architectures, systems and applications, and to evaluate alternatives and trade-offs in developing technologies for its successful deployment. In this paper, after discussing NFV and its relationship with complementary fields of Software Defined Networking (SDN) and cloud computing, we survey the state-of-the-art in NFV, and identify promising research directions in this area. We also overview key NFV projects, standardization efforts, early implementations, use cases and commercial products.

• The paper provides a comprehensive survey of NFV, detailing its transition from traditional hardware to software-based network functions.
• It explains the ETSI-defined NFV architecture, covering NFVI, VNFs, and MANO, and illustrates current implementations and integration with SDN and cloud computing.
• It identifies critical research challenges in orchestration, energy efficiency, performance, and security that must be addressed for scalable network deployments.

Network Function Virtualization: State-of-the-art and Research Challenges

The paper "Network Function Virtualization: State-of-the-art and Research Challenges" provides a comprehensive examination of the potential and current status of Network Function Virtualization (NFV) in the telecommunications industry. Authored by Rashid Mijumbi et al., this work surveys the essential aspects of NFV, its relationship with other emerging technologies, major research directions, standardization efforts, and early implementations.

Overview of NFV

NFV represents a shift from traditional hardware-based appliances to software-based network functions running on commodity hardware. This transformation is anticipated to significantly reduce CAPEX and OPEX, enabling more flexible, faster, and scalable service deployments in telecommunication networks.

NFV Architecture and Business Model

According to the ETSI architecture, NFV is composed of three primary elements: NFV Infrastructure (NFVI), Virtual Network Functions (VNFs), and NFV Management and Orchestration (MANO). NFVI provides the virtualized computing, storage, and network resources. VNFs are the software implementations of network functions running on the NFVI. MANO encompasses the orchestration and lifecycle management of both functions and infrastructural resources.

The business model proposed in this paper identifies five key players in the NFV ecosystem:

1. Infrastructure Provider (InP): Manages physical resources.
2. Telecommunication Service Provider (TSP): Leases resources to run VNFs.
3. VNF Providers (VNFPs) and Server Providers (SPs): Supply software implementations of NFs and standard servers, respectively.
4. Brokers: Facilitate the aggregation of VNFs and resources.
5. End Users: Consume the services.

Relationship with SDN and Cloud Computing

NFV is closely related to Software Defined Networking (SDN) and cloud computing but addresses different aspects:

• SDN focuses on the separation of the control and data planes, which simplifies network management and introduces programmable control.
• Cloud Computing offers on-demand resource pooling, elasticity, and scalability.

Integrating NFV with SDN and cloud computing can accelerate the deployment and operation of network services, leveraging the strengths of each technology.

Standardization Efforts

Standardization is crucial in achieving inter-operability and broad adoption of NFV. Among the critical efforts are:

• ETSI's work on defining the NFV architectural framework and specifications for MANO, security, and resilience.
• IETF's Service Function Chaining Working Group (SFC WG) addressing function chaining protocols and architecture.
• Initiatives from the Broadband Forum, the ONF for SDN, and other industry groups that are working in liaison with ETSI.

State-of-the-Art Implementations

Numerous projects and commercial products have emerged to demonstrate NFV's feasibility and potential benefits:

• HP OpenNFV, Huawei NFV Open Lab, Intel ONP, and Cisco's Open Network Strategy (ONS) reflect ongoing vendor efforts.
• Alcatel-Lucent CloudBand and Broadcom Open NFV platforms offer solutions for various NFV deployment scenarios.
• Collaborative projects like Open Platform for NFV (OPNFV) and Mobile Cloud Networking (MCN) aim to establish open frameworks and cloud-native network services.

Research Challenges in NFV

Despite significant progress, several research challenges remain:

• Management and Orchestration: Efficient orchestration, scalability, inter-operability, and automatic lifecycle management of VNFs and underlying infrastructure are pivotal areas.
• Energy Efficiency: While NFV promises energy savings, relocating network functions to data centers raises new concerns about energy consumption.
• Performance: Hardware acceleration and optimal resource allocation must be studied to ensure VNFs achieve comparable performance to traditional hardware-based solutions.
• Security, Privacy, and Trust: As VNFs handle sensitive information, robust security frameworks and privacy protection mechanisms are needed.
• Modeling of Resources, Functions, and Services: Standardized and interoperable data models for resources and functions are necessary for smooth NFV operations and management.

Additionally, exploring NFV's role in enabling the Internet of Things (IoT) and Information-Centric Networking (ICN) offers new research directions with immense potential.

Conclusion

The move towards NFV is transforming the telecommunications landscape by decoupling various network functions from specialized hardware. This paper provides an in-depth analysis of these changes, outlining research directions and practical implementation challenges that must be addressed. As standardization bodies continue their work, it is crucial for vendors and researchers to collaborate towards achieving interoperable, flexible, and efficient NFV deployments.