The traffic stream identifier (TID) indicated in the TSPEC that defines the traffic stream for the specified access category for the wireless client. Each traffic stream for a particular client must have a unique TID in the range 0-7, but per specification, any TID may map to any user priority and hence to any access category. In this product, the only supported access categories are voice and video. For a given access category, each wireless client can support one of the following: - one uplink traffic stream, or - one downlink traffic stream, or - one bidirectional traffic stream, or - one uplink and one downlink traffic stream simultaneously.