Mobile IPv6 guarantees reachability of a MN by giving the home address (HoA) to the MN. A Mobile-IPv6-compliant application of the MN performs communication without using a Care of Address (CoA), and therefore does not notify the CoA to other communication equipment. For this reason, a PDSN can provide QoS control using HoA of the MN, but cannot provide QoS control using the address (CoA) of a visited network of the MN. A QoS control function of the PDSN has means of acquiring Binding information of the MN (correspondence information between HoA and CoA), and notifying it to a PDF. The PDF transmits QoS parameters that contain the CoA of the MN to the PDSN by referring to the Binding information. By this configuration, it becomes possible for the PDSN to perform QoS control using the CoA of the MN.