A control device 1 includes a storage unit 13 that stores an upper limit value of the number of calls that can be processed in a predetermined time using a session boarder controller (SBC) and an upper limit value of the number of signal conversion rules that can be processed using the SBC, and an arithmetic operation unit 11 that allocates, to the SBC, an operator the number of calls of which is maximum from among a plurality of operators using the number of calls and the number of signal conversion rules for each operator and determines a combination of operators to be allocated to the SBC from among remaining operators such that an unused resource related to the number of calls and the number of signal conversion rules in the SBC becomes minimum, using the upper limit value of the number of calls and the upper limit value of the number of signal conversion rules read from the storage unit 13.