  In Time-Sensitive Networking (TSN), it is important to formally prove per
flow latency and backlog bounds. To this end, recent works apply network
calculus and obtain latency bounds from service curves. The latency component
of such service curves is directly derived from upper bounds on the values of
the credit counters used by the Credit-Based Shaper (CBS), an essential
building-block of TSN. In this paper, we derive and formally prove credit upper
bounds for CBS, which improve on existing bounds.
