Deriving Traffic Demands for Operational IP Networks: Methodology and Experience

Authors: Anja Feldmann, Albert Greenberg, Carsten Lund, Nick Reingold, Jennifer Rexford, and Fred True

Complete Citation

Anja Feldmann, Albert Greenberg, Carsten Lund, Nick Reingold, Jennifer Rexford, and Fred True, Deriving Traffic Demands for Operational IP Networks: Methodology and Experience, IEEE/ACM Transactions on Networking (TON) archive Volume 9 , Issue 3, Pages: 265 - 280, 2001. DOI: 10.1109/90.929850

Abstract

Engineering a large IP backbone network without an accurate network-wide view of the traffic demands is challenging. Shifts in user behavior, changes in routing policies, and failures of network elements can result in significant (and sudden) fluctuations in load. In this paper, we present a model of traffic demands to support traffic engineering and performance debugging of large Internet Service Provider networks. By defining a traffic demand as a volume of load originating from an ingress link and destined to a set of egress links, we can capture and predict how routing affects the traffic traveling between domains. To infer the traffic demands, we propose a measurement methodology that combines flow-level measurements collected at all ingress links with reachability information about all egress links. We discuss how to cope with situations where practical considerations limit the amount and quality of the necessary data. Specifically, we show how to infer interdomain traffic demands using measurements collected at a smaller number of edge links—the peering links connecting to neighboring providers.We report on our experiences in deriving the traffic demands in the AT&T IP Backbone, by collecting, validating, and joining very large and diverse sets of usage, configuration, and routing data over extended periods of time. The paper concludes with a preliminary analysis of the observed dynamics of the traffic demands and a discussion of the practical implications for traffic engineering.

Annotations

This paper proposes a model of traffic demands that captures 1) the volume of data; 2) the entry point into the ISP network; and 3) destination reachability information.

• Traffic flows in an ISP backbone.:
  

To reduce the processing requirements:

• This model measures traffic in flow-level (by enabling Netflow).
• In addition, measurements can be collected at a smaller number of edge links—the peering links connecting to neighboring providers. The paper talks about the introduced main issues, including internal traffic, ambiguous ingress point for outbound traffic, and duplicate measurement of transit traffic.