Abstract: A packet switch includes virtual output queues for mapping data units of data packets from input ports to output ports of the packet switch. The packet switch selects virtual output queues based on old age indicators of the virtual output queues and routes data units mapped at heads of the selected virtual output queues to output ports of the packet switch. Further, the packet switch may identify a data unit of a multicast data packet mapped at the head of more than one virtual output queue and contemporaneously route the data unit to more than one output port. Additionally, the packet switch may update an old age indicator to indicate a virtual output queue is old if the virtual output queue maps an unserviceable data unit of a multicast data packet and the same data unit is mapped at the head of a selected virtual output queue.

Abstract: A communication system includes a packet switch that routes data packets between endpoint devices in the communication system through virtual channels. The packet switch includes output ports each having a link bandwidth for outputting data packets. Each virtual channel is associated with an output port and is allocated a portion of the link bandwidth of the output port. The packet switch receives a data packet identifying a virtual channel at an input port, selects another virtual channel associated with the input port, routes the data packet through the packet switch, and outputs the data packet from the packet switch by using the selected virtual channel. Additionally, the packet switch may select a reliable transmission protocol, a continuous transmission protocol, or a pseudo-continuous transmission protocol for outputting the data packet from the packet switch. In some embodiments, the packet switch modifies the data packet to indicate the selected virtual channel.

Abstract: A packet switch including input ports and output ports allocates an output bandwidth of each output port among virtual channels based on bandwidth allocations values corresponding to the virtual channels and a bandwidth precision value of the output port. The bandwidth precision value indicates a number of bandwidth precision bits, which may be outside a bandwidth reservation precision range specified in a serial RapidIO standard. The packet switch receives data packets compliant with the serial RapidIO standard at the input ports, identifies an output port for each data packet, and selects input ports based on the output ports of the data packets. Further, the packet switch routes a data packet from each selected input port to the output port of the data packet, and the output port outputs the data packet by using the output bandwidth of the output port allocated to the virtual channel identified by the data packet.