Segment Routing: a Comprehensive Survey of Research Activities, Standardization Efforts and Implementation Results

Fixed and mobile telecom operators, enterprise network operators and cloud providers strive to face the challenging demands coming from the evolution of IP networks (e.g. huge bandwidth requirements, integration of billions of devices and millions of services in the cloud). Proposed in the early 2010s, Segment Routing (SR) architecture helps face these challenging demands, and it is currently being adopted and deployed. SR architecture is based on the concept of source routing and has interesting scalability properties, as it dramatically reduces the amount of state information to be configured in the core nodes to support complex services. SR architecture was first implemented with the MPLS dataplane and then, quite recently, with the IPv6 dataplane (SRv6). IPv6 SR architecture (SRv6) has been extended from the simple steering of packets across nodes to a general network programming approach, making it very suitable for use cases such as Service Function Chaining and Network Function Virtualization. In this paper we present a tutorial and a comprehensive survey on SR technology, analyzing standardization efforts, patents, research activities and implementation results. We start with an introduction on the motivations for Segment Routing and an overview of its evolution and standardization. Then, we provide a tutorial on Segment Routing technology, with a focus on the novel SRv6 solution. We discuss the standardization efforts and the patents providing details on the most important documents and mentioning other ongoing activities. We then thoroughly analyze research activities according to a taxonomy. We have identified 8 main categories during our analysis of the current state of play: Monitoring, Traffic Engineering, Failure Recovery, Centrally Controlled Architectures, Path Encoding, Network Programming, Performance Evaluation and Miscellaneous...Comment: SUBMITTED TO IEEE COMMUNICATIONS SURVEYS & TUTORIAL

Hybrid SDN Evolution: A Comprehensive Survey of the State-of-the-Art

Software-Defined Networking (SDN) is an evolutionary networking paradigm which has been adopted by large network and cloud providers, among which are Tech Giants. However, embracing a new and futuristic paradigm as an alternative to well-established and mature legacy networking paradigm requires a lot of time along with considerable financial resources and technical expertise. Consequently, many enterprises can not afford it. A compromise solution then is a hybrid networking environment (a.k.a. Hybrid SDN (hSDN)) in which SDN functionalities are leveraged while existing traditional network infrastructures are acknowledged. Recently, hSDN has been seen as a viable networking solution for a diverse range of businesses and organizations. Accordingly, the body of literature on hSDN research has improved remarkably. On this account, we present this paper as a comprehensive state-of-the-art survey which expands upon hSDN from many different perspectives

Enhancing Automated Network Management

Network management benefits from automated tools. With the recent advent of software-defined principles, automated tools have been proposed from both industry and academia to fulfill function components in the network management control loop. While automation aims to accommodate the ever increasing network diversity and dynamics with improved reliability and management efficiency, it also brings new concerns as it’s becoming more difficult to understand the control of the network and operators cannot rely on traditional troubleshooting tools. Meanwhile, how to effectively integrate new automation tools with existing legacy networks remains a question. This dissertationpresents efficient methods to address key functionalities within the control loop in the adaption of automated network management.Identifying the network-wide forwarding behaviors of a packet is essential for many network management tasks, including policy enforcement, rule verification, and fault localization. We start by presenting AP Classifier. AP Classifier was developed based on the concept of atomic predicates which can be used to characterize the forwarding behaviors of packets. There is an increasing trend that enterprises outsource their Network Function (NF) processing to a cloud to lower cost and ease management. To avoid threats to the enterprise’s private information, we propose SICS based on AP Classifier, a secure and dynamic NF outsourcing framework. Stateful NFs have become essential parts of modern networks, increasing the complexity in network management. A major step in network automation is to automatically translate high level network intents into low level configurations. To ensure those configurations and the states generated by automation match intents, we present Epinoia, a network intent checker for stateful networks. While the concept of auto-translation sounds promising, operators may not know what intents should be. To close the control loop, we present AutoInfer to automatically infer intents of running networks, which helps operators understand the network runtime states

Service-oriented system engineering

Service-Oriented System Engineering (SOSE) is one of the emerging research areas that involves a number of research challenges in engineering service-oriented systems, the architecture and computing paradigm as well as the development and management of service-oriented systems. Service-Oriented Computing (SOC) exploits services as the fundamental elements for developing computer-based systems. It has been applied to various areas and promotes fundamental changes to system architecture, especially changing the way software systems are being analyzed, architected, designed, implemented, tested, evaluated, delivered, consumed, maintained and evolved. The innovations of SOC also offer many interesting avenues of research for scientific and industrial communities. In this paper, we present the concepts of the SOSE from the related work. The motivation, opportunities and challenges of the SOSE is highlighted thereafter. In addition to this, a brief overview of accepted papers in our Special Issue on SOSE is presented. Finally we highlight and summarize this paper.N/

SDNにおけるパケット損失とループを防止するネットワーク設定更新方式の検討

今のインターネットは世界を結ぶ情報社会の基盤となっている。様々なサービスやアプリケーションはインターネット上で増加しており、ネットワークはますます複雑になっている。このような状態を打破するため新たなネットワークアーキテクチャの設計が必要となる。ソフトウェア定義ネットワーク（SDN）は、コントロールプレーンとデータプレーンを分離するネットワークへの新しいアプローチである。SDNネットワークにおいて、新しいトポロジーおよびサービスを適合させるため、ネットワークの設定を更新することは一般的である。この新しい技術を実現するため、OpenFlowという新しい技術を標準として導入される。OpenFlowプロトコルはコントロールプレーンとデータプレーンの間の通信が可能にする。しかし、全てのネットワーク機器において設定の更新が整合性を持たなければ、不一致性による問題が生じる。この問題により、ネットワークにおけるパケット損失やループなど不正確な動作が起こる可能性がある。本稿では、SDNとOpenFlowに関する関連技術を紹介し、SDNにおける不一致性問題を定義し、先行研究を交えて議論する。そして、パケット損失とループを防止するネットワーク設定更新方式を提案する。具体的にはSDNコントロールはネットワーク設定の更新前と更新後の転送経路を分析し、開放ループと閉合ループの有無により二つの経路間の関係を分類する。この関係を基づいて、スイッチ設定の更新の順番を計算し、コントロールはこの順番によってネットワーク設定を更新する。提案の正確性を検証するため、コントロールPOXとネットワークエミュレータMininet上で実装しシミュレーションを行い、TCPとUDP二つのプロトコルでリンクのスループットやパケット損失を評価した。結果としては提案手法はリンクのスループットを保証し、パケット損失を抑制を実現した。また上記の提案手法を実装するためには、コントローラとスイッチ間の遅延が大きく作用するため、コントロールとスイッチの間に遅延の測定と設置の手法を提案し、評価を行った。最後に関連研究と比較して提案方式を議論した。電気通信大学201