Topic of Presentation: Improving Network Availability through the Graceful Shutdown of BGP Sessions.

Language: English

Bruno Decraene is a Senior Network Architect at Orange Labs. He is working on short term IP routing and BGP/MPLS VPN engineering activities, mid-term projects on network architecture and IETF standardization with the aim of providing innovation within Orange networks. He has been involved in the design of the Transit VPN network (French domestic VPN network) and has been dealing with network convergence issues. Before joining Orange Labs, he was working in France Telecom on Information Systems for network management and network mediation for billing.

Abstract: For new applications – such as VoIP, on line gaming and corporate mission critical applications- customers are requesting Service Providers a better network availability. This presentation will focus on the BGP protocol which is used in most -if not all- these networks and which takes more time than the IGP to find and install the back up paths in case of failure. We’ll first see why BGP convergence can take time, even for convergence constrained within the AS. Then we’ll describe procedures for the graceful shutdown of eBGP sessions. When an alternate path is available in the AS, this allows reducing and possibly avoiding packet loss through a make-before-break behaviour. Hence, this can increase network availability or/and the ability for the ISP to perform maintenance operation during normal business hours. Finally, we’ll present testbed results illustrating the gain in various BGP topologies and forwarding scheme. This is applicable to both Internet and BGP/MPLS VPNs networks.