Note on Inherent and Imposed Priorities in Packet Switching

When messages are transmitted as a series of possibly noncontiguous packets, an effective priority is introduced which favors short messages. The strength of this effect upon transmission time is investigated and compared with schemes where an additional priority scheme is imposed. It is found that imposing a real priority structure can markedly influence delays when: first, the trunks are relatively heavily loaded, and second, the nodes' incoming traffic arrives over high-speed channels.