Computer Supported Cooperative Work (CSCW) environments have traditionally made heavy use of network technology to allow users (often at different locations) to work together via computer systems. However, this dependency of CSCW applications on the underlying network technology has up to now not been a real issue within the community. CSCW research has traditionally focused on the design of shared environment applications that run on this underlying network, e.g., the development of interaction and presentation techniques for shared tasks. Also, CSCW has been a testbed for design methodologies such as the ethnographic analysis of user behaviour. Although we support this emphasis on social science within the field, we feel that in this truly multidisciplinary area researchers should become more aware of network-related research issues. A number of parallel events can be identified that triggered our concern: " The move from Local Area Network technology to Wide Area Network technology (the global Internet) for CSCW applications. " The evolution of this Internet towards commercialization of services and the privatisation of many telecommunication service providers in Europe. " The political debate over the Information Super Highway, necessary to support the increasing bandwidth requirements typical for CSCW applications that require the use of multiple channels of information. The move towards the Internet has given us the opportunity for global participation in CSCW environments, resulting in a more generic utilization of this technology. However, the caveat for the CSCW community lies in the fact that we now no longer fully control our shared environments, and have become more dependent on the global decision-making process regarding network infrastructure. The same institution that gave our research community access to internetworking in the late-1970s, the National Science Foundation (NSF), has decided that further governmental funding of the NSFNET backbone, which constituted a major part of Internet infrastructure in the USA, is no longer required. Commercial service providers now operate major backbone services for the Internet on a commercial basis [8]. These commercial network providers thus take charge over essential pieces of Internet infrastructure, taking decisions which could have a serious impact on distributed multimedia services provided by the Internet such as the World-Wide Web and MBONE, which we'll discuss further on. In Europe, a similar development is taking place: traditional, often monopoly-based, network providers such as British Telecom and the Dutch PTT Telecom have recently been privatised and are in the process of reconsidering their tasks and services. The debate in both the USA and Europe over the Information Super Highway or National Information Infrastructure (NII) gives further evidence that governments will not be able to maintain development and support of new high-bandwidth information services in the near future. This, however, is only one network-related development that directly concerns the CSCW community. New standards are emerging for the transmission of real-time high-bandwidth data over Internet connections. This high-bandwidth data typically involve video and audio information from shared multimedia communication environments. In the next section, we will discuss what these standards might provide in terms of functionality to the CSCW community, and what constraints these standards introduce. They are often defined by network researchers who have a genuine interest in providing network capabilities, but typically do not have the same means as the CSCW community to regard cognitive ergonomical aspects of network functionality. We try to demonstrate the importance of a dialogue between the two areas of research, a cross-fertilization from which both communities will benefit. The current attitude in the CSCW community towards connectivity is very similar to the attitude towards computing power in the field of Human-Computer Interaction (HCI) in the late 1970s: the infrastructure necessary to apply our research ideas is not of our concern, and will be delivered by others. That may have been true for direct manipulation systems, but to what extend will it be true for shared real-time multimedia environments?