Resilient Interdomain Routing with Bgp – Protocols and Reliability

Interdomain routing is a key element in the global Internet routing infrastructure. A resilient interdomain routing framework is required, in order to deliver reliable and dependable data communication services. However, because the existing routing system has evolved to a large scale and legacy protocols have been widely deployed, building a resilient interdomain routing framework is challenging. In this thesis, we focus on modeling and improving the resilience of the Border Gateway Protocol (BGP). BGP is the de facto standard of Internet interdomain routing and is used in tens of thousands of Internet routers. It is prohibitively expensive and difficult to build a new interdomain routing protocol from scratch in the near future. Thus, we take an evolutionary approach to improve the reliability of BGP routing. Our research demonstrates that the robustness and the performance of interdomain routing can be increased by understanding the network routing and transport protocols rigorously and by further engineering the protocol stack system appropriately. Specifically, our investigation on the resilience of BGP falls into three aspects: robustness of BGP sessions, reliability of internal BGP (IBGP) networks, and advertising interdomain QoS routing information. First, we study the robustness of BGP sessions in temporarily failed or severely congested networks. We apply empirical and model-based approaches. These approaches allow us to systematically analyze impacts on BGP sessions, coming from (a) BGP behaviors, (b) TCP behaviors, (c) network failures, and (d) network congestion. For example, we show that the retransmission mechanism of the existing TCP is too conservative for supporting BGP