Towards a framework for network control composition

IP networks nowadays perform many functions in addition to best-effort datagram forwarding. These functions are typically achieved via an ad hoc combination of distributed protocols, database- and tool-driven router configurations, and manual configurations. In such an ad hoc system, it is difficult to anticipate any potential harmful interactions among the control functions or to provide any behavioral assurances.What kind of a framework will enable the composition of network control functions for sophisticated yet robust network control? Is it possible to have a framework in which each network control function is implemented as an independent application that runs on top of an operating platform, where the operating platform serves as an interface between the applications and the underlying network routers, provides services to facilitate the composition of applications, and ensures that network-wide operational invariants are not violated by the actions of the applications?Using an application example to illustrate, we discuss some challenges that underlie the design of such a potential operating platform. We hope this article will stimulate discussions on more principled approaches for network control composition.