Navigational devices

In our definition of a network, I specify computational or navigational devices. For the sake of this book, a navigational device is a valid network device, and constitutes a node on our network. The meaningful difference between a computational and navigational device (or resource) is that a navigational device provides no resources of its own, and instead exists only to facilitate the successful communication of other devices on the network. A simple switch or router would fall under this category. These devices are still programmed to operate successfully on a network, but are typically done at the system level in C or C++, with on-board firmware. The concerns of programming these intermediary devices will generally fall outside the purview of this book, but I wanted to note the distinction for the sake of clarity and completeness.