A virtual subscriber line terminal station device includes a software component including software to be added in accordance with a service requirement; and hardware having general-purpose functions; wherein the hardware includes a communication unit that receives a bandwidth allocation request transmitted by a subscriber line termination device; and the software component includes a bandwidth allocation component. The bandwidth allocation component has an individual unit that, based on an algorithm for allocating bands, computes a bandwidth to be allocated to the subscriber line termination device that transmitted the bandwidth allocation request; a common unit that, in accordance with the bandwidth allocated by the individual unit, allocates the bandwidth to the subscriber line termination device; and an interface between the individual unit and the common unit. The common unit converts the bandwidth allocation request received by the communication unit to a format that can be used by the individual unit. The individual unit computes the bandwidth to be allocated to the subscriber line termination device that transmitted the bandwidth allocation request that is converted, by the common unit, to a format that can be used by the individual unit.