This thesis focuses on the QUIC protocol, a recent experimental transport layer UDP-based protocol proposed by Google as a faster substitute of TCP. As QUIC is already used by Google applications and services and QUIC packets carry most of the information in encrypted form, network operators are looking for ways to monitor QUIC traffic, e.g. in order to detect and diagnose network problems and in order to optimize performance and to manage QoS. Accordingly, this work analyses and evaluates two algorithms proposed by Telecom Italia to provide QUIC with a method to passively assess its performance in terms of connection delay and loss rate.