An Investigation into Transport Protocols and Data Transport ...

9.1. Transfer Tests Across Dedicated Private Wide Area Networks 192
A series of different network conditions were created in order to monitor
the performance of New-TCP algorithms. They are described as follows:
Variable UDP Background Load
Given a static queue-size, a path may experience varying loads that would
represent the background traffic of the path. Therefore, an experiment was
devised to test the capability of these algorithms as the average queue occupancy
is increased as a result of an increase in background traffic load.
Whilst the buffer dynamic of running constant bit rate (CBR) traffic
would not be representative of the complex interactions of self-similar traffic
[CB95, LTWW94, PKC97], UDP CBR background traffic is used to simplify
understanding. As such, a custom made tool, FIP, was developed to generate
UDP based background traffic to guarantee packet delivery times of a specific
traffic profile based on the number of packets that should be sent out per
time interval.
Tests were conducted with both single and ten concurrent New-TCP flows
competing against various loads of CBR background traffic. For the case of
multiple concurrent TCP flows, the flows were distributed evenly over the
available testbed PCs in order to reduce hardware and scheduling constraints
imposed by running many flows on a single machine.
Number of Concurrent Flows
As New-TCP protocols are designed to be replacement protocols for the
Standard TCP algorithm, it is important to understand the affects of running
many flows on the network. Therefore, an experiment was devised to run
many concurrent ‘parallel’ New-TCP flows on the test networks to determine