Cyclic Queuing and Forwarding (CQF) is a mechanism of the IEEE TSN Group for providing guaranteed latency and jitter in a network. CQF deals with a common cycle time in the network and during one cycle, one queue is queuing the arriving frames when a second one is forwarding the previously queued frames. The roles are inverted at each cycle. To analyze this mechanism, we use the Network Calculus theory. It makes the computation of bounds on the delay possible and it is now largely used in the network analysis. In this paper, we show that the burstiness does not increase along the path and we provide a residual capacity for the low priority flows.