The Internet has led to the creation of a digital society, where (almost) everything is connected and is accessible from anywhere. However, despite their widespread adoption, traditional IP networks are complex and very hard to manage. It is both difficult to configure the network according to predefined policies, and to reconfigure it to respond to faults, load, and changes. To make matters even more difficult, current networks are also vertically integrated: the control and data planes are bundled together. Software-defined networking (SDN) is an emerging paradigm that promises to change this state of affairs, by breaking vertical integration, separating the network's control logic from the underlying routers and switches, promoting (logical) centralization of network control, and introducing the ability to program the network. The separation of concerns, introduced between the definition of network policies, their implementation in switching hardware, and the forwarding of traffic, is key to the desired flexibility: by breaking the network control problem into tractable pieces, SDN makes it easier to create and introduce new abstractions in networking, simplifying network management and facilitating network evolution. In this paper, we present a comprehensive survey on SDN. We start by introducing the motivation for SDN, explain its main concepts and how it differs from traditional networking, its roots, and the standardization activities regarding this novel paradigm. Next, we present the key building blocks of an SDN infrastructure using a bottom-up, layered approach. We provide an in-depth analysis of the hardware infrastructure, southbound and northbound application programming interfaces (APIs), network virtualization layers, network operating systems (SDN controllers), network programming languages, and network applications. We also look at cross-layer problems such as debugging and troubleshooting. In an effort to anticipate the future evolution of this new paradigm, we discuss the main ongoing research efforts and challenges of SDN. In particular, we address the design of switches and control platforms—with a focus on aspects such as resiliency, scalability, performance, security, and dependability—as well as new opportunities for carrier transport networks and cloud providers. Last but not least, we analyze the position of SDN as a key enabler of a software-defined environment.

https://publications.uni.lu/bitstream/10993/20596/1/survey_on_SDN.pdf

Software-Defined Networking: A Comprehensive Survey

P4 is a high-level language for programming protocol-independent packet processors. P4 works in conjunction with SDN control protocols like OpenFlow. In its current form, OpenFlow explicitly specifies protocol headers on which it operates. This set has grown from 12 to 41 fields in a few years, increasing the complexity of the specification while still not providing the flexibility to add new headers. In this paper we propose P4 as a strawman proposal for how OpenFlow should evolve in the future. We have three goals: (1) Reconfigurability in the field: Programmers should be able to change the way switches process packets once they are deployed. (2) Protocol independence: Switches should not be tied to any specific network protocols. (3) Target independence: Programmers should be able to describe packet-processing functionality independently of the specifics of the underlying hardware. As an example, we describe how to use P4 to configure a switch to add a new hierarchical label.

/pdf/p4-programming-protocol-independent-packet-processors-jlla1kwsyr.pdf

P4: programming protocol-independent packet processors

The idea of programmable networks has recently re-gained considerable momentum due to the emergence of the Software-Defined Networking (SDN) paradigm. SDN, often referred to as a ''radical new idea in networking'', promises to dramatically simplify network management and enable innovation through network programmability. This paper surveys the state-of-the-art in programmable networks with an emphasis on SDN. We provide a historic perspective of programmable networks from early ideas to recent developments. Then we present the SDN architecture and the OpenFlow standard in particular, discuss current alternatives for implementation and testing of SDN-based protocols and services, examine current and future SDN applications, and explore promising research directions based on the SDN paradigm.

/pdf/a-survey-of-software-defined-networking-past-present-and-6tt309ed7r.pdf

A Survey of Software-Defined Networking: Past, Present, and Future of Programmable Networks

Software-Defined Networking (SDN) is an emerging paradigm that promises to change this state of affairs, by breaking vertical integration, separating the network's control logic from the underlying routers and switches, promoting (logical) centralization of network control, and introducing the ability to program the network. The separation of concerns introduced between the definition of network policies, their implementation in switching hardware, and the forwarding of traffic, is key to the desired flexibility: by breaking the network control problem into tractable pieces, SDN makes it easier to create and introduce new abstractions in networking, simplifying network management and facilitating network evolution. In this paper we present a comprehensive survey on SDN. We start by introducing the motivation for SDN, explain its main concepts and how it differs from traditional networking, its roots, and the standardization activities regarding this novel paradigm. Next, we present the key building blocks of an SDN infrastructure using a bottom-up, layered approach. We provide an in-depth analysis of the hardware infrastructure, southbound and northbound APIs, network virtualization layers, network operating systems (SDN controllers), network programming languages, and network applications. We also look at cross-layer problems such as debugging and troubleshooting. In an effort to anticipate the future evolution of this new paradigm, we discuss the main ongoing research efforts and challenges of SDN. In particular, we address the design of switches and control platforms -- with a focus on aspects such as resiliency, scalability, performance, security and dependability -- as well as new opportunities for carrier transport networks and cloud providers. Last but not least, we analyze the position of SDN as a key enabler of a software-defined environment.

Network virtualization is recognized as an enabling technology for the future Internet. It aims to overcome the resistance of the current Internet to architectural change. Application of this technology relies on algorithms that can instantiate virtualized networks on a substrate infrastructure, optimizing the layout for service-relevant metrics. This class of algorithms is commonly known as "Virtual Network Embedding (VNE)" algorithms. This paper presents a survey of current research in the VNE area. Based upon a novel classification scheme for VNE algorithms a taxonomy of current approaches to the VNE problem is provided and opportunities for further research are discussed.

Virtual Network Embedding: A Survey

Today’s disruptive approaches to rearchitecting the Internet, e.g., Clean Slate Networking initiatives require testbeds that present unprecedented flexibility to the experimenter. This poster presents Berlin, a flexible testbed platform designed towards the requirements of Future Internet research. Berlin combines a diverse landscape of network elements, both software-defined and legacy hardware, and unifies them under a common management interface, presenting them as pluggable services to the experimenter.

/pdf/berlin-the-berlin-experimental-router-laboratory-for-3zkpcqpvvu.pdf

Berlin: The Berlin Experimental Router Laboratory for Innovative Networking

Methods, systems, and computer programs are presented for creating a secure network fabric and for adding trusted devices to an existing secure network fabric. One method includes an operation for setting a switch into a provisioning mode where the switch does not enforce secure communications. While the switch is in provisioning mode, the method performs operations including establishing a connection from the switch to a provisioning controller, sending a certificate signing request (CSR) from the switch to the provisioning controller, and receiving, from the provisioning controller, a security certificate generated by a certificate authority. The method further includes an operation for entering a lockdown mode by the switch after receiving the security certificate, where the switch, while in lockdown mode, secures communications utilizing the security certificate.

Systems and methods to securely construct a network fabric

A First Look at OpenFlow Control Plane Behavior from a Test Deployment

/pdf/improving-network-troubleshooting-using-virtualization-r7s40y8e7y.pdf

Improving Network Troubleshooting using Virtualization

Over the past decade, operational networks, have grown tremendously in size, performance and importance. This concerns particularly the Internet, the ultimate “network of networks.” We expect this trend to continue as more and more services traditionally provided by the local computer move to the cloud, e.g., file storage services and office applications. In spite of this, our ability to control and manage these networks remains painfully inadequate, and our visibility into the network limited. This has been exemplified by several recent outages that have caused significant disruption of important Internet services [24, 14, 149, 126]. Part of the challenges for controlling and troubleshooting networks stem from the nature of the problem: Networks are intrinsically highly distributed systems with distributed state and configuration. Consequently, a consistent view of the network state is often difficult to attain. They are also highly heterogeneous: Their scale ranges from small home-networks to data center networks that transfer enormous amounts of data at high speeds between thousands of hosts. Their geographic spread may be confined to a single rack, or span the globe. The Internet combines all these different kinds of networks, and thus their individual challenges. In addition, the network architecture and the available toolset has evolved little if at all over the past decade. In fact, the Internet core and architecture has been diagnosed with ossification [48]. Thus, debugging problems in an operational network still comes down to guesswork, as the architecture provides little support for fault localization and troubleshooting, and available tools like NetFlow, traceroute and tcpdump provide either only coarse-grained statistical insight, or are confined to single vantage points and do not provide consistent information across the network. In this thesis, we explore how to improve our control over networks and our abilities to debug and troubleshoot problems. Due to the extreme diversity of the environments, we do not strive for a one-size-fits-all solution, but propose and evaluate several approaches tailored to specific important scenarios and environments. We emphasize network centric approaches that can be implemented locally and are transparent to the end hosts. In the spirit of trusting “running code”, we implement all our approaches “on the metal” and evaluate them in real networks. We first explore the Potential of Flow Routing as an approach available to end users to self-improve their Internet Access. We find Flow-Routing to be a viable, costefficient approach for communities to share and bundle their access lines for improved reliability and performance.

/pdf/towards-improved-control-and-troubleshooting-for-operational-3q4vewqz8v.pdf

Andreas Wundsam

Papers

Berlin: The Berlin Experimental Router Laboratory for Innovative Networking

Systems and methods to securely construct a network fabric

A First Look at OpenFlow Control Plane Behavior from a Test Deployment

Improving Network Troubleshooting using Virtualization

Towards Improved Control and Troubleshooting for Operational Networks.