Operating System Support for Active Networks

AbstractActive Networks provide a network infrastructure which can be programmed on a per-user or even a per-packet basis. While the flexibility of such systems is seductive, the safety and security risks are greatlyincreased. Active network nodes must provide programmability while respecting policy constraints of the network provider and protecting nodes and other users from faulty applications. In addition, many modernapplications demand Quality of Service guarantees which will require exposing selected portions of the node resource management policy. As shared infrastructure, reliability beyond that of general purpose computingsystems is required. EROS (the Extremely Reliable Operating System) is an attractive candidate for resource managementin an Active Network node. EROS is a pure capability system which provides complete accountability for persistent, consumable and multiplexed resources. We have implemented a prototype Active Network elementon the EROS platform which provides the resource partitioning, quality of service, inter-client protection, and performance required of active networks. This paper presents the architecture, design and performance of thisprototype, which is currently running on Intel x86 platforms. 1 Introduction 1.1 What are Active Networks? An Active Network[28] consists of network elementswhich are programmable, on a per-node, per-flow, or perpacket basis. They are thus a further step in the merg-er of computing and communications, where the network infrastructure is virtual, and instantiated with the aid ofcomputing devices. The IP Internet provides a great example of a virtual infrastructure, as it provides the illusionof a large addressable network via software running on elements interconnected with heterogeneous subnets. This degree of programmability represents a major tran-sition in thinking about networks. Network elements in