Understanding the impact of internal bgp route reflection
Lixia Zhang, Jong Han Park · 2011
The Internet has been growing rapidly in its size and become denser over time, and so have Internet Service Providers (ISPs). Today, the number of BGP routers inside a large ISP can be more than one thousand and spread across different geographical locations globally. To scale with the increasing number of routers, large ISPs have developed and used more scalable i-BGP architectures such as BGP route reflection without thorough analysis of their design. This lack of such analysis escalated interests and concerns on BGP performance inside a large ISP; BGP performance inside large ISPs is no longer simple to understand and can potentially have a noticeable impact on the end-to-end data plane performance. As a first step to address these concerns, we perform measurement studies that define, quantify, and analyze two important BGP performance metrics inside large ISPs: path diversity and convergence delay. Our measurement analysis, based on BGP data collected from backbone production routers in two global-scale ISPs over a few years, shed lights on many interesting properties of existing BGP path diversity and convergence inside the ISPs, and may be useful in comprehensive and complete understanding of the end-to-end protocol performance and enhancements, more realistic simulations as well as designing the future global routing protocols.