Abstract: A new distributed scheduling algorithm in a three-stage Clos network is proposed, which combines the varied length packet and fixed length cell switch mechanism. This algorithm adopts the load-allotment scheme based on the varied length packet and a new token scheme in the input stage, which removes the cells of a packet mis-sequence in the cell switch mechanism and unfair load-allotment in the packet switch mechanism, the scheduling scheme in the central stage and output stage switches based on the fixed length cell switch mechanism, which improves the algorithm efficiency and raises the algorithm adaptability. The algorithm stability is shown by theoretical analysis. The simulation analysis demonstrates that the algorithm outdoes other algorithms in delay and adaptability.

Key words: three-stage Clos network, mixed switch mechanism, distributed scheduling, packet switching, switching networks