Minimizing queueing delays in computer networks 1

Name: Ngin Hoon Tong
Degree: Doctor of Philosophy
Dept: Electrical and Computer Engineering
Thesis Title: Minimizing Queueing Delays in Computer Networks
Abstract
The current Internet provides a best-effort packet service using the Internet
Protocol. It offers no guarantees on actual packet deliveries and users need not
make reservations before transmitting packets through it. This architecture has
been tremendously successful in supporting data applications as demonstrated by
the remarkable growth of the Internet usage over the last decade. However, as
the Internet evolves to become a global communication infrastructure, two key
weakness have become increasingly obvious. Firstly, it is unable to provide ser-
vice differentiation so that the network can utilize resources more efficiently to
support the many new real-time applications that have started to proliferate over
the Internet. Secondly, there is a lack of flow isolation within aggregated traf-
fic which allows congestion unresp onsive flows, such as User Datagram Proto col
(UDP) flows, to squeeze out the congestion responsive ones, such as Transmis-
sion Control Protocol (TCP) flows. In this thesis, an original service differentia-
tion framework, called the Delay-Rate Differentiated Services, is proposed. This
framework is able to efficiently provide delay-based service differentiation and flow
isolation within the best-effort traffic aggregates, thus resolving the key deficien-
cies of the best-effort paradigm.
Keywords: Differentiated Services, Quality of Service, Delay Differentiation, Fair
Bandwidth Allocation, Control-theoretic Approach