Abstract: With a deep understanding on the properties of stable matching in the context of multiple input-queued switches, we propose the efficient schemes to guarantee the QoS of any unicast and multicast traffic with fixed- or variable-length packets in an unified way. Using these schemes, the QoS of fixed- or variable-length unicast and multicast packets can be guaranteed by independently employing suitable service disciplines at the packets' destined outputs like what is being done in an output queueing switch. One of our proposed schemes uses totally 4N input/output buffers, each with an internal speed-up of 2 independent of N, for an N?N switch to support any fixed- or variable-length multicast and unicast packets with OoS guarantees.