There is disclosed a network communication system that includes data sources and of switches. Each of the data sources and switches is interconnected by a packet-switched network, and is synchronized to a common clock. The system also includes a network controller that maintains records of network characteristics including a transmission delay for each of the data sources and switches, and a transmission delay for links in the packet-switched network. The network controller processes the network characteristics to generate, for each of a plurality of packets of a given type of traffic: a path from a particular data source, and through at least one particular switch, and a schedule of departure times at each of the particular data source and the at least one particular switch. The path and the schedule are optimized to meet jitter requirements for the given type of traffic.