Flexible Protocol Stacks

This chapter presents flexible protocol stacks as a promising alternative to today’s static Internet architecture. Self-aware/expressive network nodes cooperate to select the protocol stacks that fulfil all communication requirements at minimal cost at run-time. Since the network conditions and the internal state of the communication peers change over time, the communication peers can dynamically adapt the flexible protocol stack to add, remove or replace protocols on-the-fly during communication. This stands in strong contrast to the traditional Internet architecture, which only supports a fixed set of protocol stacks that hardly adapt to the network dynamics. For our flexible network architecture, we adapt the concepts of self-awareness and self-expression for an autonomous observation of the node’s internal system state and the network state and an autonomous run-time management of the protocol stacks. Our self-aware network node architecture also allows us to dynamically migrate the individual protocols between hardware and software at run-time to optimise the packet processing inside the network node to the current network traffic. In this chapter, we present the methodologies with which communication peers can negotiate the optimal protocol stacks amongst each other. Furthermore, we discuss the EmbedNet execution environment that supports an adaptive hardware/software mapping of flexible protocol stacks. Prototypes of the EmbedNet execution environment have been implemented on reconfigurable system-on-chip architectures. We demonstrate the efficiency of flexible protocol stacks in two case studies.