An Investigation into Transport Protocols and Data Transport ...

1.2. Research Scope 25
• Identification that the key performance bottleneck is the replication
of large scale data across the Internet and the understanding of the
mechanisms that limit data transfer rates.
• Several new congestion control algorithms that govern the rate of data
transfer are investigated and systematically tested across laboratory
and dedicated wide-area networks, and across the Internet to determine
the benefits and disadvantages of each.
It is the aim of this dissertation to use systematic testing to highlight the
performance bottlenecks and the benefits and disadvantages of new transport
algorithms for the replication of bulk data. Furthermore the research
conducted here will help refine suitable design and implementation of high
speed Internet transport protocols.
1.2 Research Scope
This dissertation assumes that the predominant transport protocol in use on
the Internet will continue to be the Transmission Control Protocol. Also,
it is assumed that the data to be replicated is sufficiently large that the
TCP flows are ‘long lived’ and that they spends most of their time in the
‘congestion avoidance’ phase of TCP’s transmission behaviour. As such, the
improvement of congestion control algorithms will aid the performance and
fairness of all flows competing along a bottleneck link.
The effects of network topology, (multiple) bottleneck location and policing
mechanisms are not investigated.
The dissertation also takes the view that the deployment of new transport
protocol algorithms should be evolutionary rather than revolutionary. This is