Abstract: In a VoDSL (voice over digital subscriber) IAD (integrated access device) and a control method thereof capable of performing voice communication by using a PSTN when it is impossible to perform voice communication through a VoDSL service network, the VoDSL IAD includes a DSL module connected to a VoDSL service network and providing data and voice communications to plural personal computers and telephone sets; a digital processing unit for converting a voice signal received from a telephone into a digital signal format or a voice signal having a digital signal format received from the DSL module into an analog signal format; a SLIC (subscriber line interface circuit) for outputting the digital signal format voice signal from the digital processing unit to the telephone or outputting the analog signal format voice signal from the telephone to the digital processing unit; and a switching logic for performing switching operation according to a power state and connecting the SLT to the PSTN network.