Overload control and performance evaluation in a Parlay/OSA environment

To increase the pace of development and deployment of new services and
applications in telecommunication networks, new service architectures
have been proposed. Parlay/OSA is one of the proposals that has aroused
most attention. By providing network functionality via Application Program
Interfaces (APIs), Parlay/OSA facilitates creation of telecommunication
services and applications for independent software developers. With
Parlay/OSA there is no longer any requirement for knowledge and technical
skills of telecommunications when creating new applications. A Parlay/
OSA environment introduces gateways, which provide the
applications with abstracted network functionality. A gateway translates
the requests for abstracted functionality to telecommunication protocols
and signalling. Parlay/OSA is a contract driven architecture where several
constraints coexist. To fulfil the constraints and to protect the gateways
from shutting down, overload control mechanisms are needed.
This thesis proposes and evaluates different overload control mechanisms
in a Parlay/OSA environment. The main objectives of the overload
control mechanisms are to protect the system and to maintain a high
throughput. Important issues that are discussed are measurement strategies,
overload control actions, and how different priorities and time constraints
should be considered. Also, the proposed overload control
mechanisms consider some guiding principles from the specifications of
Parlay/OSA. In the scope of this thesis both distributed and single server
systems are investigated.