TOMQAT - TOtal Management of service Quality for multimedia Application infrasTructure

• End-to-End: the QoS is perceived at the end user's level and is addressed at all layers of the OSI stack (network, transport, orchestration, application)
• Dynamic: The QoS is dynamically managed depending on the evolution of the available bandwidth on the network

TOMQAT Approach

Development of a conceptual framework for QoS management

• Analysis of requirements from telecommunications actors (PNOs, service providers, end Uuers)
• Identification of performance parameters at all levels of the OSI stack as well as their mappings
• Definition of TMN functions, management policies and mechanisms for QoS management
• Development of testing strategies using measurement tools for ATM networks

End users perception of QoS and QoS management

• Definition of what QoS means according to the end users (quality of audio, delay jitter)
• User oriented aspects of dynamic QoS management

Development of a testing environment

• BALI network (Berlin ATM-LAN Interconnection)
• JVTOS, NeVoT and vic multimedia applications
• ATM 100 measurement tool dedicated to traffic generation
• TMN compliant system for the centralised QoS management based on research and market available products (OSIMIS/ISODE, ONS Q3-Adaptor)
• Simulation components (traffic models, jitter generation, ...)

Development of experimental scenarios

• Test cases to provide feedback and improve the TQM framework

Experiments

• Validation of the algorithms developed within the experimental scenarios
• Identification of pertinent performance parameter values
• Involvement of end users for assessment of the achieved QoS levels

-> to provide a unified approach to the QoS management of both network infrastructure and the applications supported thereby

TOMQAT Scenarios

• Testing of dynamic routing algorithms for ATM in order to optimise resource allocation, decrease cell loss and improve connection acceptance
• Definition of optimal playout buffer lengths that determine best trade-offs between jitter of the audio stream and the end-to-end delay
• Application control scenarios dedicated to the testing of dynamic QoS negotiation algorithms and QoS management along the connection cycle

-> Use of predefined QoS management policies from TQM systems (service provisioning, resource policing) to manage assignments of QoS levels to the end users

Results of Experiments

Selection of performance parameters that influence the QoS perceived by the end users and identification of appropriate values

• Application (frame loss ratio, frame delay jitter, end-to-end delay, ...)
• Orchestration (audio / video synchronisation, ...)
• Network, transport (cell loss rate, jitter, end-to-end delay, ...)

Enhancement of application level signalling protocols for dynamic QoS negotiation

• Detection of QoS degradation based on end-to-end feedback mechanisms (RTP protocol)
• Reduce bandwidth requirements by adjusting the video frame rate

Validation of QoS management strategies for multimedia applications helped by the feedback from end users

• Policy making, resource policing, service provisionning

Validation of testing and measurement approaches

• Traffic generation and real time analysis
• Measurement of ATM parameters
• Measurement scenarios for experiments

QoS verification

• End-to-end QoS monitoring
• Implicit assessment of QoS through mapping functions

Validation

• Experiments driven by end users satisfaction
• Refinement / improvement of the TQM framework