Submitted for publication

Existing multicomputer network routers use simple arbitration techniques such as rst-come-rst-serve or round-robin which have signiicant limitations in supporting needs in emerging multicomputer architectures and applications. More exible network resource control at the router level not only provides many beneets such as fair services, uniform resource utilization, and exible topology support, but it is also essential to support multimedia and other real-time applications. We describe and evaluate a cost-eeective network resource control algorithm called ALU-biasing arbitration. The ALU-biasing arbitration distributes output link bandwidth of a router to input links proportionally to programmed parameters. The algorithm has been implemented in the Tandem ServerNet router 17] at less than 10% of overall gate counts. The ALU-biased network can reserve virtually arbitrary amount of bandwidth to communication paths and actually can guarantee the reserved bandwidth, potentially supporting many new applications that require such. The ALU biasing arbitration also improves average network performance by evenly utilizing network resources. However, it also has limitations such as traac coupling via shared physical links and diiculty in delay bounds guarantees. We examine and discuss the problems that ServerNet solves and remaining issues.