145 research outputs found
Global state, local decisions: Decentralized NFV for ISPs via enhanced SDN
The network functions virtualization paradigm is rapidly gaining interest among Internet service providers. However, the transition to this paradigm on ISP networks comes with a unique set of challenges: legacy equipment already in place, heterogeneous traffic from multiple clients, and very large scalability requirements. In this article we thoroughly analyze such challenges and discuss NFV design guidelines that address them efficiently. Particularly, we show that a decentralization of NFV control while maintaining global state improves scalability, offers better per-flow decisions and simplifies the implementation of virtual network functions. Building on top of such principles, we propose a partially decentralized NFV architecture enabled via an enhanced software-defined networking infrastructure. We also perform a qualitative analysis of the architecture to identify advantages and challenges. Finally, we determine the bottleneck component, based on the qualitative analysis, which we implement and benchmark in order to assess the feasibility of the architecture.Peer ReviewedPostprint (author's final draft
Optical Networks and Interconnects
The rapid evolution of communication technologies such as 5G and beyond, rely
on optical networks to support the challenging and ambitious requirements that
include both capacity and reliability. This chapter begins by giving an
overview of the evolution of optical access networks, focusing on Passive
Optical Networks (PONs). The development of the different PON standards and
requirements aiming at longer reach, higher client count and delivered
bandwidth are presented. PON virtualization is also introduced as the
flexibility enabler. Triggered by the increase of bandwidth supported by access
and aggregation network segments, core networks have also evolved, as presented
in the second part of the chapter. Scaling the physical infrastructure requires
high investment and hence, operators are considering alternatives to optimize
the use of the existing capacity. This chapter introduces different planning
problems such as Routing and Spectrum Assignment problems, placement problems
for regenerators and wavelength converters, and how to offer resilience to
different failures. An overview of control and management is also provided.
Moreover, motivated by the increasing importance of data storage and data
processing, this chapter also addresses different aspects of optical data
center interconnects. Data centers have become critical infrastructure to
operate any service. They are also forced to take advantage of optical
technology in order to keep up with the growing capacity demand and power
consumption. This chapter gives an overview of different optical data center
network architectures as well as some expected directions to improve the
resource utilization and increase the network capacity
NFV Platforms: Taxonomy, Design Choices and Future Challenges
Due to the intrinsically inefficient service provisioning in traditional networks, Network Function Virtualization (NFV) keeps gaining attention from both industry and academia. By replacing the purpose-built, expensive, proprietary network equipment with software network functions consolidated on commodity hardware, NFV envisions a shift towards a more agile and open service provisioning paradigm. During the last few years, a large number of NFV platforms have been implemented in production environments that typically face critical challenges, including the development, deployment, and management of Virtual Network Functions (VNFs). Nonetheless, just like any complex system, such platforms commonly consist of abounding software and hardware components and usually incorporate disparate design choices based on distinct motivations or use cases. This broad collection of convoluted alternatives makes it extremely arduous for network operators to make proper choices. Although numerous efforts have been devoted to investigating different aspects of NFV, none of them specifically focused on NFV platforms or attempted to explore their design space. In this paper, we present a comprehensive survey on the NFV platform design. Our study solely targets existing NFV platform implementations. We begin with a top-down architectural view of the standard reference NFV platform and present our taxonomy of existing NFV platforms based on what features they provide in terms of a typical network function life cycle. Then we thoroughly explore the design space and elaborate on the implementation choices each platform opts for. We also envision future challenges for NFV platform design in the incoming 5G era. We believe that our study gives a detailed guideline for network operators or service providers to choose the most appropriate NFV platform based on their respective requirements. Our work also provides guidelines for implementing new NFV platforms
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