A Survey on Efforts to Evolve the Control Plane of Inter-Domain Routing <s> Concepts <s> Software Defined Networking (SDN) is an exciting technology that enables innovation in how we design and manage networks. Although this technology seems to have appeared suddenly, SDN is part of a long history of efforts to make computer networks more programmable. In this paper, we trace the intellectual history of programmable networks, including active networks, early efforts to separate the control and data plane, and more recent work on OpenFlow and network operating systems. We highlight key concepts, as well as the technology pushes and application pulls that spurred each innovation. Along the way, we debunk common myths and misconceptions about the technologies and clarify the relationship between SDN and related technologies such as network virtualization. <s> BIB001 </s> A Survey on Efforts to Evolve the Control Plane of Inter-Domain Routing <s> Concepts <s> Software-defined networking (SDN) abstracts low-level network functionalities to simplify network management and reduce costs. The OpenFlow protocol implements the SDN concept by abstracting network communications as flows to be processed by network elements. In OpenFlow, the high-level policies are translated into network primitives called rules that are distributed over the network. While the abstraction offered by OpenFlow allows to potentially implement any policy, it raises the new question of how to define the rules and where to place them in the network while respecting all technical and administrative requirements. In this paper, we propose a comprehensive study of the so-called OpenFlow rules placement problem with a survey of the various proposals intending to solve it. Our study is multifold. First, we define the problem and its challenges. Second, we overview the large number of solutions proposed, with a clear distinction between solutions focusing on memory management and those proposing to reduce signaling traffic to ensure scalability. Finally, we discuss potential research directions around the OpenFlow rules placement problem. <s> BIB002 </s> A Survey on Efforts to Evolve the Control Plane of Inter-Domain Routing <s> Concepts <s> Software-Defined Networking (SDN) promises to improve the programmability and flexibility of networks, but it may also bring new challenges that need to be explored. The main objective of this paper is to present a quantitative assessment of the properties of SDN backbone networks to determine whether they can provide similar availability to the traditional IP backbone networks. To achieve this goal, we have completed the following steps: i) we formalized a two-level availability model that is able to capture the global network connectivity without neglecting the essential details: ii) we proposed Markov models for characterizing the single network elements in both SDN and traditional networks: iii) we carried out an extensive sensitivity analysis of a~national and a~world-wide backbone networks. The results have highlighted the considerable impact of operational and management (OaM) failures on the overall availability of SDN. High OaM failure intensity may reduce the availability of SDN as much as one order of magnitude compared to traditional networks. Moreover, the results show that the impact of software and hardware failures on the overall availability of SDN can be significantly reduced through proper overprovisioning of the SDN controller(s). <s> BIB003 </s> A Survey on Efforts to Evolve the Control Plane of Inter-Domain Routing <s> Concepts <s> Traditional network load balancers have been developed and deployed by combining software and hardware into network appliances. This approach makes network load balancers inflexible (limited number schedule disciplines implemented), expensive and hard to perform network management tasks. Software Defined Networking (SDN) is emerging as new network paradigm that separates software and hardware roles in devices (vertical integration), enables programmability of networks, generalizes network devices and functions, and centralizes network management. Those ideas can be apply to development of new load balancers to overlap the disadvantages of traditional load balancers. Thus, this work evaluated the performance of SDN load balancers implementations with different schedule disciplines (Random, Round-Robin and CPU Usage), and the reactive and active SDN load balancers. Through careful performance evaluation based on collected data and the reviewed literature, we concluded that SDN load balancers implementations are very effective, viable, flexible and inexpensive solutions to distributed the network load. <s> BIB004
The concept type used in the proposals is one classification criterion for works to evolve the control plane . The concept is the set of principles and designs adopted by a work in the literature to approach the network research problem. Thereby, this survey classifies two concept types: Traditional and Software-Defined Networking (SDN). • Traditional: The traditional networks are characterized as all the network logic embedded into network appliances. They have a distributed nature, and to solve a specific networking problem they, need to act individually on the affected appliances and apply manual changes in their configuration. Traditional network protocols have been developed and deployed by combining software and hardware into network devices (e.g., TCP/IP). In other words, closed and proprietary network systems have been produced with long development cycles (usually years) and bring new network functionalities that frequently require the acquisition of new hardware with such features. Besides, proprietary boxes often alter the configuration, as well as the compatibility of APIs (Application Programming Interfaces) across vendors (and even across different products from the same vendors BIB001 ). Therefore, legacy and discontinued products make the integration with new network devices a hard to often impossible task  . • SDN: Software-Defined Networking (SDN) is emerging as a new network paradigm BIB002  BIB003 BIB004 . SDN proposes a separation of software-hardware from devices (vertical integration). Thereby, SDN has the potential to enable new technologies, network programmability and the flexibility of functionalities on network devices. A major feature of SDN is the decoupled control and data plane. This allows a centralization logic of the control to be fully aware of the network state, enforce network policies, routing decisions, forwarding information, and so forth. Many technologies apply the concepts of SDN. The most notable one is the OpenFlow protocol  . OpenFlow is an instantiation of the concepts of SDN BIB001 , which is becoming a standard de facto instance of SDN in the academic and industry field  . Touching upon OpenFlow, it provides a programmable interface between the OpenFlow controller (the network logic) and OpenFlow Switches (forwards packets based on controller logic). Besides, OpenFlow rules follow the concept of flow, which is a sequence of packets sent from a particular source to a particular destination following a given path  . The OpenFlow rules are capable of identifying and matching TCP/IP header fields, which can provide fine-grained rules for the definition of traffic flows inside OpenFlow networks.