Performance Analysis of Multipath BGP

TL;DR

This paper analyzes the performance of Multipath BGP, demonstrating its role in stabilizing routing, improving resilience, and enabling load balancing in large-scale Internet deployments.

Contribution

It provides the first large-scale performance analysis of M-BGP using RIPE Atlas data, highlighting its stability and load balancing benefits.

Findings

M-BGP deployment guarantees stable inter-AS routing.

M-BGP enhances network resilience to traffic variations.

M-BGP enables effective load balancing across border links.

Abstract

Multipath BGP (M-BGP) allows a BGP router to install multiple 'equally-good' paths, via parallel inter-domain border links, to a destination prefix. M-BGP differs from the multipath routing techniques in many ways, e.g. M-BGP is only implemented at border routers of Autonomous Systems (ASes); and while it shares traffic to different IP addresses in a destination prefix via different border links, any traffic to a given destination IP always follows the same border link. Recently we studied Looking Glass data and reported the wide deployment of M-BGP in the Internet; in particular, Hurricane Electric (AS6939) has implemented over 1,000 cases of M-BGP to hundreds of its peering ASes. In this paper, we analyzed the performance of M-BGP. We used RIPE Atlas to send traceroute probes to a series of destination prefixes through Hurricane Electric's border routers implemented with M-BGP. We examined the distribution of Round Trip Time to each probed IP address in a destination prefix and their variation during the measurement. We observed that the deployment of M-BGP can guarantee stable routing between ASes and enhance a network's resilience to traffic changes. Our work provides insights into the unique characteristics of M-BGP as an effective technique for load balancing.