SDN Architecture and Southbound APIs for IPv6 Segment Routing Enabled Wide Area Networks

The SRv6 architecture (Segment Routing based on IPv6 data plane) is a promising solution to support services like Traffic Engineering, Service Function Chaining and Virtual Private Networks in IPv6 backbones and datacenters. The SRv6 architecture has interesting scalability properties as it reduces the amount of state information that needs to be configured in the nodes to support the network services. In this paper, we describe the advantages of complementing the SRv6 technology with an SDN based approach in backbone networks. We discuss the architecture of a SRv6 enabled network based on Linux nodes. In addition, we present the design and implementation of the Southbound API between the SDN controller and the SRv6 device. We have defined a data-model and four different implementations of the API, respectively based on gRPC, REST, NETCONF and remote Command Line Interface (CLI). Since it is important to support both the development and testing aspects we have realized an Intent based emulation system to build realistic and reproducible experiments. This collection of tools automate most of the configuration aspects relieving the experimenter from a significant effort. Finally, we have realized an evaluation of some performance aspects of our architecture and of the different variants of the Southbound APIs and we have analyzed the effects of the configuration updates in the SRv6 enabled nodes

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

Optimizing Router Performance

To support its development of networking hardware and software, Juniper Networks conducts research into enhancements to the protocols used on the Internet, in coordination with standards bodies such as the Internet Engineering Task Force. We helped Juniper Networks with two specific research objectives. The first was to design and implement an improved algorithm by which Internet hosts can establish the appropriate packet size to maximize bandwidth while avoiding packet fragmentation. We produced a working implementation of the improved algorithm in the Linux kernel. The second objective was to measure the effect of different Internet Protocol extension headers (specifically, Routing Header Type 0, the Segment Routing Header, and the Compressed Routing Header) on router performance. We produced code for running simple benchmarks locally, as well as a formal Internet Draft specifying the procedure so that it can be run by Juniper Networks on high-performance benchmarking hardware

Proceedings of Seminar on Network Protocols in Operating Systems

The Linux networking stack tends to evolve rapidly, and while there are some excellent documentation written in the past, most of the past documentation gotten (at least partially) outdated over time. The seminar on Network Protocols in Operating Systems was arranged in Aalto University, fall 2012, Department of Communications and Networking to gain a better understanding of the current status of the networking implementation in the Linux kernel. The seminar had 10 participants and each participant was assigned a module from the Linux networking implementation, on which a short paper was to be written. This publications contain the final output of this work. The papers included in the publication are: Kurnikov, Arseny: Linux kernel application interface. Jaakkola, Antti: Implementation of transmission control protocol in Linux. Arianfar, Somaya: TCP’s congestion control implementation in Linux kernel. Budigere, Karthik: Linux implementation study of stream control transmission protocol. Khattak, Fida Ullah: The IPv4 implementation of Linux kernel stack. Boye, Magnus: Netfilter connection tracking and NAT implementation. Korhonen, Jouni: Mobile IPv6 Linux kernel and user space. Soininen, Jonne: Device agnostic network interface. Kalliola, Aapo: Network device drivers in Linux. Varis, Nuutti: Anatomy of a Linux bridge

On SRv6 Security

SRv6 is a routing architecture that can provide hybrid cooperation between a centralized network controller and network nodes: IPv6 routers maintain the multi-hop ECMP-aware segments, whereas the controller, responsible for the Traffic Engineering policy, combines them to form a source-routed path through the network. Since the state of the flow is defined at the ingress to the network and then is contained in a specific packet header, called Segment Routing Header (SRH), the importance of such a header itself is vital. Motivated by the increasing success and widespread deployment of such approaches and technologies, this paper introduces the context and discusses some of the issues tied to possible tampering with the Segment Routing Header content. Finally, some details of an experimental testbed aimed at evaluating the above issues are provided

Effectiveness of segment routing technology in reducing the bandwidth and cloud resources provisioning times in network function virtualization architectures

Network Function Virtualization is a new technology allowing for a elastic cloud and bandwidth resource allocation. The technology requires an orchestrator whose role is the service and resource orchestration. It receives service requests, each one characterized by a Service Function Chain, which is a set of service functions to be executed according to a given order. It implements an algorithm for deciding where both to allocate the cloud and bandwidth resources and to route the SFCs. In a traditional orchestration algorithm, the orchestrator has a detailed knowledge of the cloud and network infrastructures and that can lead to high computational complexity of the SFC Routing and Cloud and Bandwidth resource Allocation (SRCBA) algorithm. In this paper, we propose and evaluate the effectiveness of a scalable orchestration architecture inherited by the one proposed within the European Telecommunications Standards Institute (ETSI) and based on the functional separation of an NFV orchestrator in Resource Orchestrator (RO) and Network Service Orchestrator (NSO). Each cloud domain is equipped with an RO whose task is to provide a simple and abstract representation of the cloud infrastructure. These representations are notified of the NSO that can apply a simplified and less complex SRCBA algorithm. In addition, we show how the segment routing technology can help to simplify the SFC routing by means of an effective addressing of the service functions. The scalable orchestration solution has been investigated and compared to the one of a traditional orchestrator in some network scenarios and varying the number of cloud domains. We have verified that the execution time of the SRCBA algorithm can be drastically reduced without degrading the performance in terms of cloud and bandwidth resource costs

Operating System Response to Router Advertisement Packet in IPv6.

With growth of internet IPv4 address will run out soon. So the need of new IP protocol is indispensable. IPv6 with 128-bit address space is developed and maintain the support of IPv4 protocols with some upgrades such as BGP, OSPF and ICMP. ICMP protocol used for error reporting, neighbor discovering and other functions for diagnosis, ICMP version 6 has new types of packets to perform function similar to address resolution protocol ARP called Neighbor Discovery Protocol NDP. NDP is responsible for address auto configuration of nodes and neighbor discovery. It define new packets for the purposes of router solicitation, router advertisement and others discovery functions