Network performance monitoring at small time scales

ABSTRACT

SNMP statistics are usually collected over intervals of 5 minutes and correspond to average activity of IP links and network elements for the duration of the interval. Nevertheless, reports of traffic performance across periods of minutes can mask out performance degradation due to short-lived events, such as micro-congestion episodes, that manifest themselves at smaller time scales. In this paper we perform a measurement study of packet traces collected inside the Sprint IP network to identify the time scales over which micro-congestion episodes occur. We characterize these episodes with respect to their amplitude, frequency and duration. We define a new performance metric that could be easily computed by a router and reported every 5 minutes through SNMP to shed light into the micro-behavior of the carried traffic. We show that the proposed performance metric is well suited to track the time scales over which micro-congestion episodes occur, and may be useful for a variety of network provisioning tasks.

REFERENCES

• 1: C. Fraleigh et al. Provisioning IP Backbone Networks to Support Latency Sensitive Traffic. In IEEE Infocom, San Francisco, March 2003.
• 2: K. Papagiannaki. Provisioning IP Backbone Networks Based on Measurements. PhD thesis, University College London, March 2003.
• 3: K. Papagiannaki et al. Measurement and Analysis of Single-Hop Delay on an IP Backbone Network. In IEEE JSAC, vol. 21, no. 6, August 2003.
• 4: M. Schoffstall et al. A Simple Network Management Protocol (SNMP). RFC 1157, May 1990.
• 5: Z.-L. Zhang et al. Small-Time Scaling behaviors of internet backbone traffic: An Empirical Study. In IEEE Infocom, San Francisco, March 2003.

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.3 Network Operations
          Subjects: Network monitoring

General Terms:
Algorithms, Design, Management, Measurement, Performance

Keywords:
congestion detection, internet measurement, performance monitoring