A parameter determination apparatus is provided with: an input/output I/F configured to receive topology information representing connections between nodes included in a communication system, and node pair information indicating node pairs that communicate with each other; a parameter determination unit configured to simultaneously determine, based on the topology information and the node pair information, a group formed of 1 or more node pairs and a transmission rate to be assigned to the group; and a parameter setting unit configured to give notification of the group and the transmission rate to the nodes included in the communication system. In this way, network utilization efficiency is increased.