Towards programmable networks

Abstract

Intermediate nodes (e.g., routers, switches) of current networks, in contrast with end nodes (e.g., PCs workstations), are vertically integrated closed systems. Their functions, mostly implemented by embedded software, are rigidly built-in by intermediate nodes vendors. Vendors must follow designs dictated by slow and intractable standard committees rather than pursue rapid introduction of innovative cost-effective technologies. There is thus a need for new technologies that would enable programming intermediate nodes with the same simplicity of programming end-nodes. This paper describes the NetScript project, pursuing agent-based middleware for programming functions of intermediate network nodes. Delegated agents are used to deploy functions in intermediate nodes. The NetScript programming language provides means to script processing of packet streams; it is particularly suitable to program routing, packet analyzers or signalling functions. This paper describes an architecture for programmable network nodes; middleware for agent-based programming of these nodes; the NetScript language to program node functions and applications of these technologies to create programmable SNMP agents, protocol analyz-ers, signalling and routing protocols and firewalls. 2