Source Routing-Based In-band Network-Wide Telemetry System

With the ever-increasing complexity of networks,fine-grained network monitoring enables better network reliability and timely feedback control.The Software-defined networks(SDN)obtain enormous attention in mutual research and industry communities.SDN can be deployed in a variety of conditions including data center(DC)networks,wide area networks,and enterprise networks.In SDN,monitoring is a key role to convey information about the network and their controlling consequences made with the help of an SDN controller.However,existing monitoring approaches such as SNMP,Net-Flow and S-Flow are based on typically sampling and polling of the switch/routers CPU's and have performance and granularity limitations.In complex networks or traditional networks once,an error occurred in a network it will difficult to get the error type and locate the error location.We use P4-language to build a system to solve this problem.P4-language is a high-level programing language that defines how packet processed by a network forwarding devices.In this thesis,we present a technique that extracts real-time data of a network device using a P4-based INT(In-band Network Telemetry)technique.INT is a new technique that is able to provide fine-grained,real-time,and end-to-end network monitoring.INT works by embedding network information into every packet and allows data packets to query switch-internal state such as queue depth,queue latency,and link utilization accurately.However,INT only specifies an underlying device-level primitive while how to achieve network-wide traffic monitoring remains undefined.INT further requires a high-level mechanism built upon it to efficiently extract the network-wide traffic status.SDN is widely deployed,the controller always expects a global view(i.e.,network-wide visibility)to make the optimal traffic control decisions.The contribution of this thesis is to design a wide-telemetry framework by coupling the INT probe with source routing label stack to guide packet in the network for a specified path monitoring.INT is used to achieve link load information in the network.Moreover,we address the uncontrollable path issue via the technique of source routing.The experimental data shows INT-path can encode network-wide traffic status into the series of a bitmap image in real-time.The system performance is optimum,with INT probe generation and different background traffic rate.By measuring the system performance,we come to several conclusions that could guide the user on how to use network-wide telemetry.Furthermore,for INT path deployment in real networks,we recommend that the telemetry granularity be correctly arranged into the"comfort zone",considering both the switch buffer size and the background traffic rate.