I am still on a quest to find means of testing low bitrate applications at high resolutions (3ms). Recently ngtcp2 (w/quic) got BBR support, and is written in C so getting at the cmsg data appears feasible. https://github.com/ngtcp2/ngtcp2 -- Latest Podcast: https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/ Dave Täht CTO, TekLibre, LLC