This document describes Tetrys, which is an on-the-fly network coding protocol that can be used to transport delay-sensitive and loss-sensitive data over a lossy network. Tetrys may recover from erasures within an RTT-independent delay thanks to the transmission of coded packets. This document is a record of the experience gained by the authors while developing and testing the Tetrys protocol in real conditions. This document is a product of the Coding for Efficient NetWork Communications Research Group (NWCRG). It conforms to the NWCRG taxonomy described in RFC 8406.