Quality of Service Guarantees in High Speed Networks A Research Project Funded by the National Science Foundation
Principal Investigator: R. L. Cruz
Summary of Results
- H. Sariowan, R. L. Cruz, and G. C. Polyzos, "Scheduling for Quality of Service Guarantees via Service Curves," Proceedings of the International Conference on Computer Communications and Networks (ICCCN) 1995, Las Vegas, September 20-23, 1995, pp. 512-520. Full paper (211K,postscript).
We propose a new scheduling policy, called SCED (Service Curve-based Earliest Deadline first), which provides guarantees to virtual circuits in packet switched networks. This scheduling policy is developed for a general framework for service provisioning based on Service Curves proposed by Cruz. Instead of explicitly guaranteeing a specific quality of service measure, such as maximum delay, SCED guarantees the service curve for a connection. Quality of service guarantees for the connection can then be expressed as simple functions of the service curve guarantee and the traffic burstiness constraint of the connection. A simple and convenient condition under which SCED can simultaneously guarantee a set of service curves is proved. The service curve specification gives greater flexibility to a server in allocating its resources to meet diverse delay and throughput requirments. We demonstrate by an example that SCED provides aa larger schedulability region than scheduling policies such as Virtual-Clock and PGPS with rate proportional assignment.