POSTECH DPNM Lab

Introduction Providing Quality-of-Service (QoS) to users of distributed multimedia services is a difficult problem. The service user must be given the capabiltiy to express his requirements for the receiving service in terms of QoS parameters familiar to him. It requires a vertically integrated architecture that can deliver end-to- end QoS guarantees at multiple levels of an entire distributed system. We present an object-oriented QoS management middleware for managing QoS of distributed multimedia services and applications. A key component in this middleware is QoS Management Service Object (QMSO), providing multimedia applications with QoS management service APIs.

POSTECH DPNM Lab Related Work Int-serv Architecture –Provides controlled QoS for multimedia applications over an integrated services internetwork. OSI QoS Framework –Defines terminology and concepts for QoS and provides a model which identifies objects of interest to QoS in open system standards QoS-A –Provides a layered architecture of services and mechanisms for quality of service management QuAL –Quality Assurance Language (QuAL) for the specification of QoS constraints on underlying computing and communication platforms. Quality of Service for CORBA Objects ( QuO) –Supports QoS at the CORBA layer and extends the CORBA functional Interface Description Language (IDL) with a QoS Description Language (QDL)

POSTECH DPNM Lab QoS Management Framework QoS Management API Multimedia App. QMSO QoS Specification QoS Mapping QoS Monitor Admission Control QoS Negotiation QoS MIB QMSO QoS Specification QoS Mapping QoS Monitor Admission Control QoS Negotiation QoS MIB Multimedia App. Multimedia Session Service Object QMIO Multimedia Communication Service Object QMIO Network Service Object QMIO System Service Object QMIO Service Objects

POSTECH DPNM Lab QoS Management Information Base (MIB) QoS MIB can be used to monitor and control QoS values in multimedia services Composed of 4 Informational Groups –Service, Application, System and Network QoS MIB can be extended by adding the service-specific QoS management information

POSTECH DPNM Lab QMSO Services (1) QoS Specification –The value of QoS parameter can be acquired using the three methods device specification, off-line testing and on-line testing QoS Monitoring –QoS monitoring modes: a query mode and a report mode –We use the report mode Negotiation and Renegotiation –The QoS parameters are exchanged between server and client through peer-to-peer negotiation and layer-to-layer negotiation peer-to-peer negotiation : between server and client layer-to-layer negotiation : between the layers

POSTECH DPNM Lab QMSO Services (2) QoS Mapping –Maps one layer QoS parameters onto other QoS parameters and vice versa (bidirectional translation) One-to-one mapping, Mixing and Splitting (Demultiplexing) Admission Control –The QMSO performs admission control at both layers : system and network –System level device quality test, local schedulability test, end-to-end (EED) delay test and buffer allocation test –Network level throughput test, rate control test and network EED delay test

POSTECH DPNM Lab Procedure of QoS Services

POSTECH DPNM Lab Prototype Implementation of QoS Management System

POSTECH DPNM Lab Video Conferencing Example with QoS Guarantees

POSTECH DPNM Lab Conclusion & Future Work We presented a QoS management framework which includes QoS Management Service Object (QMSO) and a generic QoS MIB. As a realization of the QoS management framework, object-oriented QoS management middleware has been developed. This provides distributed multimedia applications with QoS management APIs. It simplifies the development and maintenance of distributed multimedia applications, providing QoS guarantees. We also described our effort on the prototype implementation of a Web-based QoS management system for MAESTRO. The prototype QoS management system uses OrbixWeb to interface with the management server, which is implemented as a CORBA object. This QoS management middleware can be used to provide QoS in CORBA-based as well as non-CORBA-based multimedia systems.

POSTECH DPNM Lab