Better QUIC implementations with Nesquic

QUIC represents a re-design of the transport stack in response to the requirements of modern applications. While it provides a myriad of benefits, studies have shown that its performance penalties in several contexts keep it from being more widely adopted. While these studies provide a good overview of when QUIC can lack performance compared to TCP, they do little to specifically pinpoint where in the QUIC stack these slowdowns come from and how they can be fixed. To address this gap, we present Nesquic, a testing infrastructure for QUIC stacks. It collects library-internal metrics of each stack component without changing the library's source code. Our preliminary findings show that not only can Nesquic help developers pinpoint which components of their QUIC stacks are less performant, but it also gives them actionable insights into fixing these issues.