June 17, 1993 4:09 pm The DTM Gigabit Network 1 The DTM Gigabit Network Christer Bohm 1 , Per Lindgren 1 , Lars Ramfelt 1 , Peter Sjödin 2 Abstract DTM is a fiber-optic network, based on bandwidth reservation and with support for dynamic reallocation of bandwidth. It is designed for real-time multimedia applications and for high-speed computer communication. DTM uses a novel medium-access technique and provides a multicast connection-oriented service. Several DTM net- works can be connected into one large network. A prototype imple- mentation and testbed is being constructed. 1 Introduction Fiber-optic networks running at several gigabits per second will be the main information carriers in the future. They will replace the current networks for CATV, telephone traffic and data communication and integrate the functions of these into one network. Also, high- speed fiber-optic networks will have new important areas of applications, such as distrib- uted multimedia with audio and video communication. MultiG is a Swedish research pro- gram focusing on distributed multimedia applications, and on how they can be supported by high-speed optical networks [15]. Distributed multimedia applications impose many requirements on networks. First, the network should have sufficient capacity to carry high-quality video and audio signals. It should have short response time to support person-to-person communication with audio and video. These applications also require timely delivery of data. For instance, video images may have to be presented on video screens at regular intervals. Finally, the net- work should support broadcasting so that one sender can efficiently transmit to many receivers. DTM is a networking project within the MultiG program. It is a project to design and build a prototype of a fiber-optic high-speed network. This network is based on a new medium access technique—the Dynamic synchronous Transfer Mode, from which the project has its name. The DTM project further includes development of protocols, network resource management and network architecture. We will use the term “DTM network”, or just “DTM”, to refer to all these components in the project. 1. Department of Teleinformatics, Royal Institute of Technology, Stockholm, Sweden, {bohm,perl,lars- h}@it.kth.se 2. SICS, Box 1263, 16428 Kista, Sweden, peter@sics.se