Implementation: Client side to increase accuracy, we need to filter the replies we get "clock filter", implementing an algorithm by David Mills basically, from 8 replies received from a peer, use the one with the lowest delay, and invalidate all older replies bad network connection results in poor accuracy punish peers with bad network connection - currently only based on packet loss once punished, a peer needs to get a number of replies to us that we consider good before the peer is marked valid again and affects the total offset calculation