ABSTRACT
Computer networks such as the Internet have traditionally provided asynchronous communication, which uses packet-switching and store-and-forward techniques. Telephone networks, on the other hand, have provided real-time communication using circuit-switching and time-division techniques. Asynchronous transfer mode (ATM) has been introduced to provide all kinds of services; however, it has been demonstrated again and again that ATM cannot cope with those services that require high quality of service (QoS) guarantees such as voice, video, and hi-fi audio in an economically satisfactory manner. Internet protocol (IP) over ATM has been found to be
a less elegant combination of protocols. A need exists for a transfer mode that can accommodate real-time as well as nonreal-time traffic. Also, with the large amount of data transfer capacity offered by the current fiber networks, the processing and buffering at switch and access points on the
network is causing a bottleneck problem. Against this background, dynamic synchronous transfer mode (DTM) was developed.1-3
DTM is a new transport network technology designed specifically for the foreseen explosion of real time media in the next-generation networks. It is a broadband network architecture conceived in 1985 and developed at the Royal Institute of Technology, Sweden. It is an attempt to combine the advantages of both asynchronous and synchronous media access schemes. It is a networking scheme designed to fully utilize the capacity of optical fiber as a physical medium by emphasizing simplicity and avoiding computation-intensive policing, queuing, buffering, and control mechanism. This is achieved through the technology’s inherent characteristics, which include dynamic bandwidth allocation, low propagation delay, almost zero delay variation, full traffic isolation between channels, and high-speed transmission.
