Eine dienstorientierte Methodik zur Koppelung von Netz-QoS-Architekturen

In recent years, distributed IT applications were developed which
pose explicit requirements on the quality of end-to-end connections
between the participating parties. Examples include voice-over-IP,
video conferencing etc. Hence, those applications' functionality is
significantly influenced by the underlying network infrastructures
on which applications build upon. Services offered by networks must
therefore meet certain criteria of quality - they have to provide
and enforce quality-of-service (QoS). For this reason, different
architectures have been and still are being developed to realize
QoS on the network level. While such architectures have proven to
be functional in principle for homogeneous networks of single
providers, the situation is completely different when it comes to
interconnecting autonomous or/and heterogeneous networks. Today, no
QoS-enabled network services are offered which span multiple
provider domains. But this is expected and necessary for the
future, last but not least because of the pressure imposed by the
application level. As there is no universal QoS architecture on the
horizon to become accepted globally, ways have to be found to
handle heterogeneity in a network of networks. --- When reviewing
existing work in the field, it becomes evident that most approaches
are limited to specific architectures or certain services. What is
still missing is a universal internetworking architecture which
could be applied in any situation and to any QoS architecture. The
existence of such a generic architecture seems to be uncertain
regarding the complexity of the task and the broad spectrum of QoS
architectures which have to covered. --- This thesis strictly
follows a service-oriented approach which can be summarized as "a
generic way for gaining a specific solution". The approach consists
of two major steps. The starting point of the first step are the
QoS network services which are to be coupled as well as the QoS
architectures these services are built upon. Initially, a
normalized representation of the architectures is gained by
modeling. In doing so, static and dynamic aspects of QoS
architectures are considered. Afterwards, the modeling of QoS
network services itself takes place and is based on the models for
architectures. The whole modeling process creates a normalized
starting point for the second major step. It consists of a generic
methodology for gaining specific solutions to solve the coupling
problem for individual cases. In this step the necessary
architectural building blocks and the required workflows for the
coupling are identified. The modeling as well as the methodology
are strictly service-oriented, especially in considering the whole
service life cycle for both parts. --- The generic model and the
methodology are illustrated by a series of examples which are
derived from real world scenarios. The thesis' results are
supported by an analysis of different business use cases, e.g. bid
invitation, estimation of effort etc.