Routing and Caching in Information-Centric Networking

학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2015. 2. 권태경.When the Internet was designed decades ago, main applications are resource sharing such as remote login and file transfer. To support such applications, the key principle in the Internet architecture is point-to-point communications, and the key element is an IP address that identifies a host. Due to the flexible design of the Internet, a wide range of new applications and services have been introduced over the decades. The recent surge of Internet traffic is mainly attributed to applications such as web, P2P file sharing, and video streaming. In such applications, an end user is mostly interested in content itself, not in a particular host or its location. Over the past few years, there have been many efforts to address the above issues from a content centric perspective. Those proposals are collectively called Information Centric Networking (ICN), which is largely deemed as a clean-slate approach. Most of the ICN studies think of content as a key element and hence assume a new paradigm by shifting from host-oriented communications to content-oriented i communications. Consequently, instead of locator-based routing, most ICN proposals consider name-based routing, which decouples content production and consumption in time and space domains. The decoupling enhances content availability and naming persistency, and supports in-network caching, multicast and mobility. Most of ICN proposals use content names as routing entries, and thus the routing scalability is primary concern. ICN allows in-network caching as a built-in functionality. However, if network nodes make caching decisions individually, duplicate copies of the same content may exist among nearby nodes. To address these problems, this dissertation proposes a unified framework named Coordinated Routing and Caching (CoRC) that mitigates routing scalability and enhances the efficiency of the in-network storage.Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i I. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 II. Design Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1 How to Make FIBs Scalable? . . . . . . . . . . . . . . . . . . . . . 4 2.2 Where to Place the Cached Item? . . . . . . . . . . . . . . . . . . . 5 2.3 How to Coordinate between Routing and Caching? . . . . . . . . . 5 2.4 How to Reflect the Current Internet Infrastructure and Business? . . 6 III. RelatedWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 IV. CoRC: Coordinated Routing and Caching . . . . . . . . . . . . . . 9 4.1 Name Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 4.2 Routing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 4.2.1 Intra-domain Routing . . . . . . . . . . . . . . . . . . . . . 11 4.2.2 Inter-domain Routing . . . . . . . . . . . . . . . . . . . . . 12 4.3 Caching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 V. Optimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 5.1 Assigning PID prefix to RR . . . . . . . . . . . . . . . . . . . . . . 15 5.2 Hybrid Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 VI. Routing Scalability . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 6.1 AS-FIB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 6.2 PAR-FIB and PIB . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 6.3 Numbers of Entries of Three Tables . . . . . . . . . . . . . . . . . 22 VII. Network Performance . . . . . . . . . . . . . . . . . . . . . . . . . . 24 7.1 Performance Metrics . . . . . . . . . . . . . . . . . . . . . . . . . 24 7.2 Compared Schemes . . . . . . . . . . . . . . . . . . . . . . . . . . 25 7.3 Experimental Setting . . . . . . . . . . . . . . . . . . . . . . . . . 26 7.4 Average Cache Hit Ratio . . . . . . . . . . . . . . . . . . . . . . . 27 7.5 Content Delivery Latency . . . . . . . . . . . . . . . . . . . . . . . 29 7.6 Traffic Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 7.7 Route Stretch vs. Topology . . . . . . . . . . . . . . . . . . . . . . 36 VIII.Packet Processing Time in a Router . . . . . . . . . . . . . . . . . . 38 8.1 Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 8.2 Drop Rate vs. Interest Packet Rate . . . . . . . . . . . . . . . . . . 39 IX. Discussions and Future Work . . . . . . . . . . . . . . . . . . . . . . 41 9.1 Hashing by Publisher Name . . . . . . . . . . . . . . . . . . . . . 41 9.2 Dealing with Router Failure . . . . . . . . . . . . . . . . . . . . . 42 9.3 Resolution System and Multihoming . . . . . . . . . . . . . . . . . 42 X. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44Docto

Virtualization and Distribution of the BGP Control Plane

The Internet is organized as a collection of networks called Autonomous Systems (ASes). The Border Gateway Protocol (BGP) is the glue that connects these administrative domains. Communication is thus possible between users worldwide and each network is responsible of sharing reachability information to peers through BGP. Protocol extensions are periodically added because the intended use and design of BGP no longer fit the current demands. Scalability concerns make the required internal BGP (iBGP) full mesh difficult to achieve in today's large networks and therefore network operators resort to confederations or Route Reflectors (RRs) to achieve full connectivity. These two options come with a set of flaws of their own such as route diversity loss, persistent routing oscillations, deflections, forwarding loops etc. In this dissertation we present oBGP, a new architecture for the redistribution of external routes inside an AS. Instead of relying on the usual statically configured set of iBGP sessions, we propose to use an overlay of routing instances that are collectively responsible for (I) the exchange of routes with other ASes, (II) the storage of internal and external routes, (III) the storage of the entire routing policy configuration of the AS and (IV) the computation and redistribution of the best routes towards Internet destinations to each client router in the AS

OFFICER: A general Optimization Framework for OpenFlow Rule Allocation and Endpoint Policy Enforcement

International audienceThe Software-Defined Networking approach permits to realize new policies. In OpenFlow in particular, a controller decides on behalf of the switches which forwarding rules must be installed and where. However with this flexibility comes the challenge of the computation of a rule allocation matrix meeting both high-level policies and the network constraints such as memory or link capacity limitations. Nevertheless, in many situations (e.g., data-center networks), the exact path followed by packets has not significant impact on performances as long as packets are delivered to their final destination decided by the endpoint policy. It is thus possible to deviate part of the traffic to alternative paths so to better use network resources without violating the endpoint policy. In this paper, we propose a linear optimization model of the rule allocation problem in resource constrained OpenFlow networks with loose routing policies. We show that the general problem is NP-hard and propose a polynomial time heuristic, called OFFICER, that aims to maximize the amount of carried traffic in under-provisioned networks. Our numerical evaluation on four different topologies show that exploiting various paths allows to increase the amount of traffic supported by the network without significantly increasing the path length

Compact routing for the future internet

The Internet relies on its inter-domain routing system to allow data transfer between any two endpoints regardless of where they are located. This routing system currently uses a shortest path routing algorithm (modified by local policy constraints) called the Border Gateway Protocol. The massive growth of the Internet has led to large routing tables that will continue to grow. This will present a serious engineering challenge for router designers in the long-term, rendering state (routing table) growth at this pace unsustainable. There are various short-term engineering solutions that may slow the growth of the inter-domain routing tables, at the expense of increasing the complexity of the network. In addition, some of these require manual configuration, or introduce additional points of failure within the network. These solutions may give an incremental, constant factor, improvement. However, we know from previous work that all shortest path routing algorithms require forwarding state that grows linearly with the size of the network in the worst case. Rather than attempt to sustain inter-domain routing through a shortest path routing algorithm, compact routing algorithms exist that guarantee worst-case sub-linear state requirements at all nodes by allowing an upper-bound on path length relative to the theoretical shortest path, known as path stretch. Previous work has shown the promise of these algorithms when applied to synthetic graphs with similar properties to the known Internet graph, but they haven't been studied in-depth on Internet topologies derived from real data. In this dissertation, I demonstrate the consistently strong performance of these compact routing algorithms for inter-domain routing by performing a longitudinal study of two compact routing algorithms on the Internet Autonomous System (AS) graph over time. I then show, using the k-cores graph decomposition algorithm, that the structurally important nodes in the AS graph are highly stable over time. This property makes these nodes suitable for use as the "landmark" nodes used by the most stable of the compact routing algorithms evaluated, and the use of these nodes shows similar strong routing performance. Finally, I present a decentralised compact routing algorithm for dynamic graphs, and present state requirements and message overheads on AS graphs using realistic simulation inputs. To allow the continued long-term growth of Internet routing state, an alternative routing architecture may be required. The use of the compact routing algorithms presented in this dissertation offer promise for a scalable future Internet routing system

Scalability and Resilience Analysis of Software-Defined Networking

Software-defined Networking (SDN) ist eine moderne Architektur für Kommunikationsnetze, welche entwickelt wurde, um die Einführung von neuen Diensten und Funktionen in Netzwerke zu erleichtern. Durch eine Trennung der Weiterleitungs- und Kontrollfunktionen sind nur wenige Kontrollelemente mit Software-Updates zu versehen, um Veränderungen am Netz vornehmen zu können. Allerdings wirft die Netzstrukturierung von SDN neue Fragen bezüglich Skalierbarkeit und Ausfallsicherheit auf, welche in dezentralen Netzstrukturen nicht auftreten. In dieser Arbeit befassen wir uns mit Fragestellungen zu Skalierbarkeit und Ausfallsicherheit in Bezug auf Unicast- und Multicast-Verkehr in SDN-basierten Netzen. Wir führen eine Komprimierungstechnik für Routingtabellen ein, welche die Skalierungsproblematik aktueller SDN Weiterleitungsgeräte verbessern soll und ermitteln ihre Effizienz in einer Leistungsbewertung. Außerdem diskutieren wir unterschiedliche Methoden, um die Ausfallsicherheit in SDN zu verbessern. Wir analysieren sie auf öffentlich zugänglichen Netzwerken und benennen Vor- und Nachteile der Ansätze. Abschließend schlagen wir eine skalierbare und ausfallsichere Architektur für Multicast-basiertes SDN vor. Wir untersuchen ihre Effizienz in einer Leistungsbewertung und zeigen ihre Umsetzbarkeit mithilfe eines Prototypen.Software-Defined Networking (SDN) is a novel architecture for communication networks that has been developed to ease the introduction of new network services and functions. It leverages the separation of the data plane and the control plane to allow network services to be deployed solely in software. Although SDN provides great flexibility, the applicability of SDN in communication networks raises several questions with regard to scalability and resilience against network failures. These concerns are not prevalent in current decentralized network architectures. In this thesis, we address scalability and resilience issues with regard to unicast and multicast traffic for SDN-based networks. We propose a new compression method for inter-domain routing tables to address hardware limitations of current SDN switches and analyze its effectiveness. We propose various resilience methods for SDN and identify their key performance indicators in the context of carrier-grade and datacenter networks. We discuss the advantages and disadvantages of these proposals and their appropriate use cases. Finally, we propose a scalable and resilient software-defined multicast architecture. We study the effectiveness of our approach and show its feasibility using a prototype implementation