Software Defined Networking Sample Clauses

Software Defined Networking. Software-Defined Networking (SDN) introduces an open interface between the forwarding hardware (responsible for packet switching) of routers and switches and its control component (responsible for instructing the switches). The OpenFlow protocol [2] is currently considered as the de facto standard for a south-bound SDN-interface (SBI). As depicted in Figure 3, traditional routers consist of three main components: i) data or user plane functionality for forwarding packets, ii) a control plane or operating system in charge of interconnecting the local data plane with routing functionality, and iii) control applications in charge of routing and information distribution between routers (e.g., using BGP or OSPF). In SDN, these three functionalities are decoupled, and a network node is mainly reduced to forwarding device, with a thin layer of control functionality (control agent) which can communicate with external control plane logic using an open interface like OpenFlow. Control functionality responsible for routing, can now be executed at a (logically) centralized control entity (SDN controller). SDN control functionality usually consists of a network operating system (NetOS) running a collection of application modules, such as topology discovery, path computation, resource management, and load balancing. The network control applications interact with the NetOS using a north-bound interface (NBI). As an in-depth discussion of SDN technology and research is out of scope of this document, we forward the interested reader to [3].

Software Defined Networking. ‌ The SDN concept was introduced during the introduction in chapter 1, this section seeks to give a more thorough introduction to the SDN concept. 3.1.1 SDN in relation to Cognitive Networks‌ The general SDN concept is not a new concept in terms of networking. A similar concept which has existed for several years before the invention of SDN is called cognitive networks, which was first introduced by ▇▇▇▇▇▇ et al. [2005]. The concept of cognitive networks is shown in figure 3.1. Figure 3.1: Cognitive networks model [▇▇▇▇▇▇ et al., 2005]. The idea is to be able to guarantee E2E goals for traffic in a network. This is achieved by creating a layered abstraction model of the network, such that applications in the top layer become independent of the deployment and physical hardware used in the network. The applications present the system with a set of requirements, which the rest of the system, then must seek to fulfil. The bottom layer, which is called Software Adaptive Network, is a software-based network, which makes is possible to change configurations in individual switches in real-time. The Cognitive Process, which is the middle layer, handles the interpretation between the E2E goals and the actions that are applied to the network in order to fulfil the goals. In ▇▇▇▇▇▇ et al. [2005] it is proposed to implement the cognition using a feedback loop called Observe Orient Decide and Act (OODA). The OODA concept is shown in figure 3.2. 3.1. Software-Defined Networking 17 Figure 3.2: The OODA model as presented in [▇▇▇▇▇▇ et al., 2005]. The OODA loop consists of four processes, where Observe is the first one. During Observe the state of the environment is obtained. Orient will then process the observed state of the system. When Orient has processed the state of the system, the Decide process must determine if and what actions to apply to the environment based on the outcome of the Orient process. Finally, the Act process must carry out the actions that the Decide process determined were necessary to apply to the environment. When cognitive networks were presented in 2005 it was not possible to create an actual Software Adaptive Network, due to technical limitations, which limited the usefulness of cognitive networks at that time. SDN is however a realisation of the Software Adaptive Network, which makes is possible to apply the concepts from cognitive networks to an actual network, and not just a simulated network. 3.1.2 What is SDN?‌ Figure 3.3 shows the concept ...

Software Defined Networking. ‌ Nowadays, management is based mainly on software systems allowing different levels of automation of the different management processes. In this sense, Software Defined Networking (SDN) has swiftly become an important aspect of the strategy to address the network management requirements as identified by the commercial players in this market. From a functional perspective, SDN can be considered as the physical separation of the network control plane from the forwarding plane, where a control plane controls several devices [ONF-SDN]. The Open Networking Foundation (ONF) [ONF], a user-driven organization dedicated to the promotion and adoption of SDN through open standards development, describes SDN as an emerging architecture that is dynamic, manageable, cost-effective, and adaptable, making it ideal for the high-bandwidth, dynamic nature of today’s applications. This architecture decouples the network control and forwarding functions enabling the network control to become directly programmable and the underlying infrastructure to be abstracted for applications and network services. ONF declares that SDN architecture is: • Directly programmable: network control is directly programmable because it is decoupled from forwarding functions. • Agile: abstracting control from forwarding lets administrators dynamically adjust network- wide traffic flow to meet changing needs.

Software Defined Networking. CBTS will provide network services for the customer network that consists of the CPE leased to the Customer. The following RACI chart outlines the roles and responsibilities for common network management activities: Network Design Specifications (Equipment not a part of the SD-WAN service) R, A C, I Firewall Service Requirements (On-Site services not a part of the SD-WAN service) R, A C, I Network Design Specifications (SD-WAN Equipment) I, C R, A LAN Configuration I, C R, A Firewall Security Configuration C, A R, I Business Policy Configuration (SD-WAN Services) I, C R, A DMZ Configuration requiring less than 30 minutes I, C R, A DMZ Configuration requiring more than 30 minutes R, A C

Software Defined Networking. Software Defined Networking (SDN) is a novel networking architecture paradigm conceived to overcome some of the most acute shortcomings of today’s DCN architectures, namely – the static nature, the management complexity, and the vendor lock in. Conceived in the academia for opening up the networking field to innovation and renewal, SDN has received lots of attention from the innovative industry segments, e.g. big data centre and cloud providers. Today, SDN concepts – decoupling the data plane from the control plane, logically centralizing the control plane, and providing well defined interfaces, both between the controller and the network elements and between the controller and the applications – are being actively incorporated into DCN solutions, by DCN owners and by networking vendors. In June 2104 ONF has published the SDN architecture document [35] where the basic principles are outlined and further elaborated to include the management plane and to develop advanced ideas, e.g. interaction between the controllers, both for multi-domain support and for building control hierarches. Figure 7-1 presents the concise representation of ONF’s SDN architecture that includes all the major components – the controller, the network elements, the management, the applications, and the interfaces between them. We foresee, therefore, that basing COSIGN architecture on SDN principles will ensure the flexibility and the agility of a data centre control and management system and enable the support of many of the requirements associated with performance and adaptability.