DiffServ architecture has been widely adopted for the provision of QoS over the Internet. This makes the full understanding of its operation imperative. We believe that only mathematical analysis may have the power of such goal. As the heart of a DiffServ router is the token bucket algorithm, a generic one, with two-colours marking, is to be considered here. A mathematical framework will be first developed for its analysis.

A sparse wireless sensor network for forest fire detection is considered. It is assumed that two types of malicious nodes can exist in this network. The malicious behaviors are assumed to be concealed through some statistical behavior. A lightweight centralized trust-based model is proposed to detect malicious or misbehaving nodes. We assume that all nodes contribute to this process through the gathering of statistical data related to communication with their neighbors. These data are periodically sent to a base station, where all trust functions are executed.