Title
Part III: routers with very small buffers
Abstract
Internet routers require buffers to hold packets during times of congestion. The buffers need to be fast, and so ideally they should be small enough to use fast memory technologies such as SRAM or all-optical buffering. Unfortunately, a widely used rule-of-thumb says we need a bandwidth-delay product of buffering at each router so as not to lose link utilization. This can be prohibitively large. In a recent paper, Appenzeller et al. challenged this rule-of-thumb and showed that for a backbone network, the buffer size can be divided by pN without sacrificing throughput, where N is the number of ows sharing the bottleneck. In this paper, we explore how buffers in the backbone can be significantly reduced even more, to as little as a few dozen packets, if we are willing to sacrifice a small amount of link capacity. We argue that if the TCP sources are not overly bursty, then fewer than twenty packet buffers are sufficient for high throughput. Specifically, we argue that O(log W) buffers are sufficient, where W is the window size of each ow. We support our claim with analysis and a variety of simulations. The change we need to make to TCP is minimal--each sender just needs to pace packet injections from its window. Moreover, there is some evidence that such small buffers are sufficient even if we don't modify the TCP sources so long as the access network is much slower than the backbone, which is true today and likely to remain true in the future. We conclude that buffers can be made small enough for all-optical routers with small integrated optical buffers.
Year
DOI
Venue
2005
10.1145/1070873.1070886
Computer Communication Review
Keywords
Field
DocType
small buffer,part iii,all-optical buffering,small amount,access network,all-optical routers,small enough,congestion control,tcp source,backbone network,small integrated optical buffer,buffer size,tcp,internet routers,rule of thumb,high throughput,bandwidth delay product
Bottleneck,Computer science,Network packet,Computer network,Static random-access memory,Network congestion,Router,Throughput,Backbone network,Access network,Distributed computing
Journal
Volume
Issue
ISSN
35
3
0146-4833
Citations 
PageRank 
References 
64
3.39
5
Authors
5
Name
Order
Citations
PageRank
Mihaela Enachescu1785.03
Yashar Ganjali2144488.79
Ashish Goel33039244.56
Nick McKeown4132471201.05
Tim Roughgarden54177353.32