Cyclic Queuing and Forwarding (CQF) is a mechanism defined by IEEE TSN for providing low jitter in a deterministic network. CQF uses a common time cycle and two buffers per node output port: during one cycle incoming packets are stored in one buffer while packets in the other buffer are being transmitted; at the end of a cycle, the roles of the two buffers are exchanged.
CQF provides very simple bounds on latency and jitter, assumed that each buffer is empty at the end of its transmission cycle.
The cycle start times are determined by a time offset that may be different for every output buffer. A guard band at both cycle ends is devised in order to compensate for misalignment and timing inaccuracies. The proper operation of CQF requires that the guard band and the offsets are computed such that nodes are sufficiently time-aligned.
I will present the work done to configure CQF, show the properties of the parameters related to CQF and explain the behaviour of them regarding the network parameter.
Lieu : grande salle de réunions dans la coursive du bâtiment R de l'ONERA à Toulouse.
Lien visio : https://rdv.onera.fr/seminaireDTIS