Mastering Internet of Things

Limitations of CoAP

As with HTTP, CoAP suffers from a topology problem. You need to choose in which direction communication is to be performed. If a firewall exists between two endpoints, the client needs to be the one residing inside the firewall, and the server needs to reside outside. The alternative is to open a hole in the firewall to allow external entities to access your device. Since management of such security privileges is difficult to manage in a dynamic network, vulnerabilities are easy to create unknowingly.

The next chapter will discuss a setup where we switch roles, and devices become clients instead of servers as in this example. In such cases, sensors report data to a central server, which can act as a broker. Brokers can ...