Real-world packet routing networks differ in many ways from the networks which are analyzable by current-day queueing theory methods. For example the service distributions in real-world networks are constant, whereas the vast majority of queueing theory applies most powerfully to exponential service distributions.
Consequently, it is desirable to at least be able to approximate the behavior of real-world networks by networks which we know how to analyze. Towards this end, much previous research has been done showing that for many networks greater variance (in service-time distributions and other things) leads to greater congestion, and therefore we can obtain upper bounds on delays in real-world networks by computing the delay in a related network, having more variance, which we know how to analyze.
The class of networks for which greater variance leads to greater congestion is not known. This paper contributes to determining this classification by demonstrating a network for which increasing the variance in either of two very different ways leads to smaller delays.
The arguments we make in this paper are not traditional to the field of queueing theory and are much more in the spirit of discrete mathematics.
Title
Greater Variance Does Not Necessarily Imply Greater Average Delay
Published
1994-07-01
Full Collection Name
Electrical Engineering & Computer Sciences Technical Reports
Other Identifiers
CSD-94-821
Type
Text
Extent
16 p
Archive
The Engineering Library
Usage Statement
Researchers may make free and open use of the UC Berkeley Library’s digitized public domain materials. However, some materials in our online collections may be protected by U.S. copyright law (Title 17, U.S.C.). Use or reproduction of materials protected by copyright beyond that allowed by fair use (Title 17, U.S.C. § 107) requires permission from the copyright owners. The use or reproduction of some materials may also be restricted by terms of University of California gift or purchase agreements, privacy and publicity rights, or trademark law. Responsibility for determining rights status and permissibility of any use or reproduction rests exclusively with the researcher. To learn more or make inquiries, please see our permissions policies (https://www.lib.berkeley.edu/about/permissions-policies).
