Copyright 2012 IEEE. Reprinted with permission.

26th IEEE International Conference on Advanced Information Networking and Applications (AINA)
Fukuoka, Japan, March 2012

Harsh RED: Improving RED for Limited Aggregate Traffic

Ilpo Järvinen, Aaron Yi Ding, Aki Nyrhinen, Markku Kojo
Department of Computer Science 
University of Helsinki

A bottleneck router typically resides close to the
edge of the network where the aggregate traffic is often limited
to a single or a few users only. With such limited aggregate traffic
Random Early Detection (RED) on the bottleneck router is not
able to properly respond to TCP slow start that causes rapid
increase in load of the bottleneck. This results in falling back
to tail-drop behavior or, at worst, triggers the RED maximum
threshold cutter that drops all packets causing undesired break
for all traffic that is passing through the bottleneck. We explain
how TCP slow start, ACK clock and RED algorithm interact in
such a situation, and propose Harsh RED (HRED) to properly
address slow start in time. We perform a simulation study
to compare HRED behavior to that of FIFO and RED with
recommended parameters. We show that HRED avoids tail-drop
and the maximum threshold cutter, reduces queue lengths, and
provides less bursty drop distribution.

IEEE AINA 2012 Conference Proceedings publication DOI.

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