  The novel blockchain generation of Byzantine fault-tolerant (BFT) state
machine replication (SMR) protocols focuses on scalability and performance to
meet requirements of distributed ledger technology (DLT), e.g.,
decentralization and geographic dispersion. Validating scalability and
performance of BFT protocol implementations requires careful evaluation. While
experiments with real protocol deployments usually offer the best realism, they
are costly and time-consuming. In this paper, we explore simulation of
unmodified BFT protocol implementations as as a method for cheap and rapid
protocol evaluation: We can accurately forecast the performance of a BFT
protocol while experimentally scaling its environment, i.e., by varying the
number of nodes or geographic dispersion. Our approach is resource-friendly and
preserves application-realism, since existing BFT frameworks can be simply
plugged into the simulation engine without requiring code modifications or
re-implementation.
