This paper presents the assessment of the speech input and output modules of a spoken dialog system which is accessed via a telephone connection. The spoken dialog system is being developed under the European INSPIRE project. It is used to control a smart home environment. The mentioned modules are assessed separately, with the help of a remote access simulation tool to model degradations which are typical for today's telephone lines. This tool generates impairments in a controlled way, in order to quantify their impact on recognition performance and on speech output quality. First results for the effects of coding impairments on the input and output modules of the INSPIRE dialog system are presented and discussed.