QoS-aware resource management for distributed multimedia applications

• Authors: Klara Nahrstedt;Hao-hua Chu;Srinivas Narayan
• Venue: Journal of High Speed Networks - Special issue on multimedia networking
• Year: 1998

The ability of operating system and network infrastructure toprovide end-to-end quality of service (QoS) guarantees inmultimedia is a major acceptance factor for various distributedmultimedia applications due to the temporal audio-visual andsensory information in these applications. Our constraints on theend-to-end guarantees are (1) QoS should be achieved on ageneral-purpose platform with a real-time extension support, and(2) QoS should be application-controllable.In order to achieve the users acceptance requirements and tosatisfy our constraints on the multimedia systems, we need aQoS-compliant resource management which supports QoS negotiation,admission and reservation mechanisms in an integrated andaccessible way. In this paper we present a new resource model and atime-variant QoS management, which are the major components of theQoS-compliant resource management. The resource model incorporates,the resource scheduler, and a new component, the resource broker,which provides negotiation, admission and reservation capabilitiesfor sharing resources such as CPU, network or memory correspondingto requested QoS. The resource brokers are intermediary resourcemanagers; when combined with the resource schedulers, theyprovide a more predictable and finer granularity control ofresources to the applications during the end-to-end multimediacommunication than what is available in current general-purposenetworked systems.Furthermore, this paper presents the QoS-aware resourcemanagement model called QualMan, as a loadable middleware, itsdesign, implementation, results, tradeoffs, and experiences. Thereare trade-offs when comparing our QualMan QoS-aware resourcemanagement in middleware and other QoS-supporting resourcemanagement solutions in kernel space. The advantage of QualMan isthat it is flexible and scalable on a general-purpose workstationor PC. The disadvantage is the lack of very fine QoS granularity,which is only possible if supports are built inside the kernel.Our overall experience with QualMan design and experiments showthat (1) the resource model in QualMan design is very scalable todifferent types of shared resources and platforms, and it allows auniform view to embed the QoS inside distributed resourcemanagement; (2) the design and implementation of QualManis easily portable; (3) the good results for QoSguarantees such as jitter, synchronization skew, and end-to-enddelay, can be achieved for various distributed multimediaapplications.