Abstract-In this paper, we study traffic demands in an IP bacbkone, identtfy the routes used by these demands, and evaluate trafJic granularity levels that are attractive for improving the poor load balancing that our study reveals. The data used in this study was collected at a major POP in a commercial Tier-l IP backbone. In the$rst part of this paper we ask two questions. What is the trafJic demand between a pair of POPS in the backbone? How stable is this demand? We develop a methodology that combines packet-level traces from access links in the POP and BGP routing information to build components of POP-to-POP trafJic matrices. Our analysis shows that the geographic spread of trafJic across egress POPS is far from uniform. In addition, we$nd that the time of day behaviors for different POPS and dtfferent access links also exhibit a high degree of heterogeneity. In the secondpart of this work, we examine commercial routing practices to assess how these demands are routed through the backbone. WeJind that traffic between a pair of POPS is engineered to be restricted to a few paths and that this contributes to widely varying link utilization levels. The natural question that follows from these findings is whether or not there is a better way to spread the traffic across backbone paths. We identify trafJic aggregates based on destination address prefixes andJind that this set of criteria isolates a few aggregates that account for an overwhelmingly large portion of inter-POP trafJic. We demonstrate that these aggregates exhibit stability throughout the day on perhour time scales, and thus form a natural basis for splitting traf$c over multiplepaths to improve load balancing.
In REF Bhattacharyya et al. study traffic dynamics at POP-level and access-link-level in a major POP (Point-Of-Presence) in a commercial Tier-1 IP backbone.
Pop-level and access-link-level traffic dynamics in a tier-1 POP
IMW '01
Computer Science