Multimedia applications, such as computer-based conferencing systems, require the use of communications services providing low transmission delays and the integration of various media. The needs of real-time multimedia applications within the office environment are analyzed. The needs of multimedia conferencing systems and image browsing applications are considered. The analysis is done by taking into account the use of current computer technologies and advanced public communications services. In particular, the use of available communications facilities, i.e., T1 links and frame-relaying packet mode services is analyzed. The main objective is to define system configurations for supporting real-time multimedia office applications making use of public communications services.