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

Opportunistic off-path content discovery in information-centric networks

Recent research in Information-Centric Networks has considered various approaches for discovering content in the cache-enabled nodes of the network. Such approaches include scoped flooding and deploying a control plane protocol to disseminate the cache contents in the network, to name a few. In this work, we consider an opportunistic approach that uses trails left behind by data packets from the content origin to the sources in order to discover off-path cached content. We evaluate our approach using an ISP topology for various system parameters. We propose two new forwarding strategies built on top of our approach. Our results indicate that the opportunistic discovery mechanism can significantly increase cache hit rate compared to NDN's default forwarding strategy, while limiting the overhead at acceptable levels

Traffic Control in Packet Switched Networks

This thesis examines traffic control options available in two existing routing solutions in packet-switched networks. The first solution is the shortest path hop-by-hop routing deployed with the OSPF or IS-IS routing protocol and the IP forwarding protocol. This is the initially deployed and still the most popular routing solution in the Internet. The second solution is explicit routing implemented with the RSVP-TE or CR-LDP signalling protocol and the MPLS forwarding protocol. This is the latest solution to have become widely deployed in the Internet. The thesis analyses the limitations of the two routing solutions as tools for traffic control and yields new insights that can guide the analysis and design of protocols involved in the process. A set of recommendations for modifications of the existing protocols is provided which would allow for a range of new traffic control approaches to be deployed in packet-switched networks. For future routing solutions which comply with the proposed recommendations two new algorithms are presented in the thesis. They are called the Link Mask Topology (LMT) algorithm, and the Link Cost Topology (LCT) algorithm. The two algorithms define a set of routing topologies and assign network traffic to routes available in these topologies aiming to simultaneously achieve high network throughput and fair resource allocation. While there are similarities in the operation of the two algorithms, their applicability is different as they allocate resources to multiple paths between two network nodes which are available in the defined routing topologies according to a different rule set. The LMT algorithm directs traffic sent between any pair of network nodes to a single route. The LCT algorithm directs traffic sent between a pair of network nodes to a number of routes. The performance of the two proposed algorithms is evaluated in the thesis with calculations comparing them to the shortest path routing algorithm in a number of test cases. The test results demonstrate the potentials of the two proposed algorithms in improving the performance of networks which employ shortest path routing

ICedge: When Edge Computing Meets Information-Centric Networking

In today’s era of explosion of Internet of Things (IoT) and end-user devices and their data volume, emanating at the network’s edge, the network should be more in-tune with meeting the needs of these demanding edge computing applications. To this end, we design and prototype Information-Centric edge (ICedge), a general-purpose networking framework that streamlines service invocation and improves reuse of redundant computation at the edge. ICedge runs on top of Named-Data Networking, a realization of the Information-Centric Networking vision, and handles the “low-level” network communication on behalf of applications. ICedge features a fully distributed design that: (i) enables users to get seamlessly on-boarded onto an edge network, (ii) delivers application invoked tasks to edge nodes for execution in a timely manner, and (iii) offers naming abstractions and network-based mechanisms to enable (partial or full) reuse of the results of already executed tasks among users, which we call “compute reuse”, resulting in lower task completion times and efficient use of edge computing resources. Our simulation and testbed deployment results demonstrate that ICedge can achieve up to 50× lower task completion times leveraging its networkbased compute reuse mechanism compared to cases, where reuse is not available