Volume 57, Issue 5 - Special Issue: Software Defined Networking and Network Function Virtualization / Andreas Gladisch, Wolfgang Kellerer

Telecom network operators face rapidly changing business needs. Due to their dependence on long product cycles they lack the ability to quickly respond to changing user demands. To spur innovation and stay competitive, network operators are investigating technological solutions with a proven track record in other application domains such as open source software projects. Open source software enables parties to learn, use, or contribute to technology from which they were previously excluded. OSS has reshaped many application areas including the landscape of operating systems and consumer software. The paradigm shift in telecommunication systems towards Software-Defined Networking introduces possibilities to benefit from open source projects. Implementing the control part of networks in software enables speedier adaption and innovation, and less dependencies on legacy protocols or algorithms hard-coded in the control part of network devices. The recently proposed concept of Network Function Virtualization pushes the softwarization of telecommunication functionalities even further down to the data plane. Within the NFV paradigm, functionality which was previously reserved for dedicated hardware implementations can now be implemented in software and deployed on generic Commercial Off-The Shelf (COTS) hardware. This paper provides an overview of existing open source initiatives for SDN/NFV-based network architectures, involving infrastructure to orchestration-related functionality. It situates them in a business process context and identifies the pros and cons for the market in general, as well as for individual actors.

Carrier networks are faced with continuous transformations of their technology platforms in order to keep up with the changing customer demands. This paper will show how the transition from stovepipe networks to layered architectures enabled the shift to a future network design based on a network operation system (NetOS) operating the ICT fabric containing merely any kind of resources. Basic, underlying concepts are presented and detailed how they will be integrated in this environment. Software components and related development and management processes are becoming an integrated part of this future carrier environment, representing a softwarization of carrier networks. Key technology enablers are Software Defined Networking and Network Function Virtualisation as well as general availability of compute, storage and networking resources. Existing “Network as a Service” approach benefit from this improvements with virtualization, control plane flexibility and adoption of Operation, Administration and Maintenance (OAM) feature to the latest developments. But carrier services will need additional improvements, resulting in the the presented paradigm of “Generic Resources as a Service”. This novel concept will fulfill most demands for flexible service composition, multi-provider and -domain support, automated deployment and operation.

This paper presents Telefónica approach for virtualizing residential customer premises equipment (vCPE), showing how the equipment at a customer's home can be simplified and how the management of resources and services improves as a result. This use case of virtualization enables the operator to shift most functions from the residential gateways towards the carrier own network, by running them on general-purpose servers at the operator premises. This makes it possible that network functions such as IP routing, IP address management (DHCP), address translation (NAT), firewall, Set Top Box functionalities (live TV, VoD, etc.), etc. are maintained and upgraded from the most efficient location. Because of the expected high impact onto the economics of the Telco network operations, the virtualization of the CPE is considered by the authors as one promising use case of Network Virtualization technologies. The virtual CPE approach is being tested in Brazil (where Telefónica operates under the Vivo brand), and represents a great opportunity for learning lessons on development and deployment of Virtual Network Functions (VNFs). Some of them are summarized in this paper.

Software-Defined Networking and network virtualization are current topics in networks research. An increased flexibility on the optical layer and demands for more dynamic bandwidth control make them candidates to transform optical networking as well. This paper reviews the general concepts, recent progress and open issues toward SDN controlled flexible optical networks.

The introduction of Software Defined Networking (SDN) and Network Functions Virtualization (NFV) has transformed the way networks will be built in the future. This development also applies to mobile networks and their evolution. How the SDN and NFV concepts will be integrated exactly is still an open research question with multiple approaches and techniques in discussion. This article provides an overview of the current discussion points with regard to development paths, building blocks, deployment scenarios, and the opportunities and challenges of the new concepts in the mobile core network context.

The 5th Generation of mobile networks (5G) is expected to be rolled out by 2020. New and revolutionary applications are already being envisioned, real-time control of machines, the Tactile Internet for wireless, Industry 4.0, the Internet of Things and self-driving cars, among others. To make this possible important enhancements and improvements in today's existing telecommunication technologies form an end-to-end perspective are required. Early testing and fast prototyping of new approaches and solutions will help to shape the evolving technologies. One of the technical enablers for 5G are two concepts based on the softwarisation and virtualisation of the core network, known as Software Defined Networking (SDN) and Network Function Virtualisation, NFV. Fraunhofer FOKUS has set up the Open5GCore testing environment to start shaping, together with its partners, the nascent 5G technologies by addressing these topics together with other relevant technological developments. After a short motivation, the architecture of the open5GCore is presented, followed by a functional description of supported features.

This paper argues that SDN and NFV principles are going to impact not only the evolution of current networks, but also the services and applications platforms. In fact, SDN and NFV, together with Cloud and Edge Computing, can be seen as facets of a broader systemic innovation wave (called softwarization) which is transforming the overall telecommunications and ICT ecosystems. Specifically, the paper proposes the vision of Software Defined Infrastructures (SDI) as highly dynamic and pervasive telecommunications and ICT frameworks of logical resources capable of executing (with a trade-off of centralisation and distribution) any network and service functions. Eventually, it is argued that, in this evolution towards SDI, the border between the networks and the Cloud-Edge Computing platforms will gradually disappear. On the other side, also the distinction between the networks and the future “terminals” (e. g., including machines, smart things, drones, robot) will blur. This transformation will have profound techno-economic implications for the telecommunications and ICT ecosystems, paving the way to the Digital Society and the Digital Economy.

In the last decade, computer-generated images have become a vital and integral part of our everyday lives. The quality of these images depends considerably on the geometric representation of the underlying virtual 3D environments. Subdivision surfaces, one such representation, have been found to be very useful due to their unique geometric properties. These properties led to the adaptation of subdivision surfaces as a movie industry standard for modeling 3D geometry, making subdivision surfaces indispensable in today's film productions. However, despite the high surface quality of subdivision surfaces, the complexity of underlying calculations requires a significant computational budget. In this thesis, we address this problem and propose novel algorithms to accelerate the evaluation of subdivision surfaces by several orders of magnitude. This enables the rendering of high-quality movie content on commercially available desktop computers within only a few milliseconds, opening up the possibility of using subdivision surfaces in real-time applications (e. g., video games). The results of this work have been made publicly available in Pixar's open source initiative OpenSubdiv , which is used in many industry applications (e. g., Maya, a modeling software by the industry leader Autodesk). Our algorithms can also be found in video games such as Activision's best seller Call of Duty: Ghosts , where we now can enjoy the surface quality of movies.