A communication device management program that enables efficient use of memory space in receiving data using remote direct memory access (RDMA) techniques. The receiving node transmits a virtual ID corresponding to a receiving process to a remote sending node. A sending process in the sending node specifies this virtual ID when starting data transmission. If the receiving node has not reserved a memory area corresponding to that virtual ID, the sending node transmits a reservation request to the receiving node, which causes a data receiving memory area to be reserved for use by a communication device in the receiving node. In the sending node, the sending communication device begins sending transmission data in RDMA mode, from a memory area managed by the sending process to the reserved data receiving memory area. The receiving communication device directs incoming transmission data to a memory area managed by the receiving process.