End-to-end quality of service for high-end applications

High-end networked applications such as distance visualization, distributed data analysis, and advanced collaborative environments have demanding quality of service (QoS) requirements. Particular challenges include concurrent flows with different QoS specifications, high bandwidth flows, application-level monitoring and control, and end-to-end QoS across networks and other devices. We describe a QoS architecture and implementation that together help to address these challenges. The General-purpose Architecture for Reservation and Allocation (GARA) supports flow-specific QoS specification, immediate and advance reservation, and online monitoring and control of both individual resources and heterogeneous resource ensembles. Mechanisms provided by the Globus Toolkit are used to address resource discovery and security issues when resources span multiple administrative domains. Our prototype GARA implementation builds on differentiated services mechanisms to enable the coordinated management of two distinct flow types—foreground media flows and background bulk transfers—as well as the co-reservation of networks, CPUs, and storage systems. We present results obtained on a wide area differentiated services testbed that demonstrate our ability to deliver QoS for realistic flows.