the nature of the beast : recent traffic measurements from an Internet backbone

Contents 1. Introduction 2. Coral measurement architecture 1. Hardware 2. Software 3. Measurement methodology 4. FreeBSD Unix port 5. Packet header trace format 6. OC12mon 3. Measurement points 4. Results 1. Packet sizes 2. Composition of traffic by protocol 3. Per flow averages (overall and per application) 4. Lengths of packet troops 5. IP fragment counts 6. IP address prefix length distribution 7. IP address space utilization 5. Summary 6. Future plans and conclusions 7. Acknowledgements 8. References abstract As described in last years Inet '97 paper [1], MCI has implemented a high-performance, low-cost monitoring system that can monitor Internet traffic (cell/packet headers) and perform analyses, and deployed them on OC-3 trunks within iMCI's backbone and also within the NSF-sponsored vBNS (very High performance Backbone Service). This publicly-available tool facilitates measurement and analysis of high-speed OC-3, and now OC-12, trunks that carry hundreds of thousands of simultaneous flows. As a follow up to last year's paper, we provide some new data analyses as well as comparisons with last year's data that may suggest trends in changing workload profiles. All the data in this paper is based on recent wide-area MCI Internet backbone traffic as recorded by the Coral monitors. Everything you've learned in school as "obvious" becomes less and less obvious as you begin to study the universe. For example, there are no solids in the universe. There's not even a suggestion of a solid. There are no absolute continuums. There are no surfaces. There are no straight lines.