boydn@jacana.lcs.mit.edu said:
Second, to what degree do you believe Internet traffic exhibits self-similarity, and how does this change with varying levels of traffic aggregation? I have read papers from Bellcore and others suggesting that no matter the level of aggregation (be it a single Internet user or a major NAP), Internet traffic exhibits high degrees of self-similarity - but more recent research does not seem to agree with this.
I think the key here is aggregation and congestion control algorithms. In the case of the Bellcore study, they were looking at high speed devices on LANs, and possibly aggregation levels in the few thousand devices (not all active) per line. The current OC3C pipes at the core of major networks are seeing aggregations orders of magniture greater in terms of concurrent active sessions (I remember hearing numbers approaching 10^6 over a year ago.) This combined with many areas of congestion and the end-to-end nature of congestion control makes any simple model, either statistical independence or self similar, suspect. just my opinion, jerry