  In this paper, we argue that existing concepts for the design and
implementation of network stacks for constrained devices do not comply with the
requirements of current and upcoming Internet of Things (IoT) use cases. The
IoT requires not only a lightweight but also a modular network stack, based on
standards. We discuss functional and non-functional requirements for the
software architecture of the network stack on constrained IoT devices. Then,
revisiting concepts from the early Internet as well as current implementations,
we propose a future-proof alternative to existing IoT network stack
architectures, and provide an initial evaluation of this proposal based on its
implementation running on top of state-of-the-art IoT operating system and
hardware.
