> The first aspect of our design is network serialization, where all OUM packets for a particular group are routed through a sequencer on the common path. This

> The first aspect of our design is network serialization, where all OUM packets for a particular group are routed through a sequencer on the common path. This solution actually just shunts the problem to a different layer. To be robust to sequencer failure and rollover, you will need to rely on an inner consensus protocol to choose sequencers. Which is basically how Multi-Paxos, Raft, etc work--you use the costly consensus protocol to pick a leader, and thereafter simply rely on the leader to serialize and ensure consistency. It seems like an interesting paper w/ a novel engineering model and useful proofs. But from an abstract algorithmic perspective it doesn't actually offer anything new, AFAICT. There are an infinite number of ways to shuffle things around to minimize the components and data paths directly reliant on the consensus protocol. None obviate the need for an underlying consensus protocol, absent problems where invariants can be maintained independently.