An algorithm is proposed to detect elephant flows. It assumes the flow rates are under Pareto distribution and the algorithm is as follows:

- Sample packet at probability \(p\)
- For each sampled packet, if the flow already exists in the counter array, increment the counter
- If the flow doesn’t exists in the counter array, evict a counter if possible and put this flow into the counter, initialize to zero
- A eviction pointer scans the counter array, whenever a new
flow comes, it does following:
- If the current counter greater than threshold, cut half
- Repeat this until you see a counter below threshold, which you clear the counter for that new flow

In the paper, equation is proposed to find the relation between the sampling probability \(p\) and eviction cycle \(t\).

## Bibliographic data

```
@inproceedings{
title = "ElephantTrap: A low cost device for identifying large flows",
author = "Yi Lu and Mei Wang and Balaji Prabhakar and Flavio Bonomi",
howpublished = "SHPI",
booktitle = "Proc 15th IEEE Symposium on High-Performance Interconnects",
year = "2007",
}
```