Christer Bohm

Fast circuit switching for the next generation of high performance networks

Dynamic synchronous transfer mode (DTM) is a broadband network architecture based on fast circuit-switching augmented with dynamic reallocation of resources. It provides a service based on multicast, multirate channels with short setup delay and supports applications with real-time requirements on quality of service as well as applications with bursty, asynchronous traffic. The paper describes the DTM architecture and its distributed resource management scheme. Performance analysis results from network simulations are presented. The analysis is performed with respect to throughput and access delay for two network topologies: a dual bus and a grid of dual buses. The effects of varying user requirements, internode distances and transfer size are studied for uniform traffic patterns. The results indicate that the overhead for establishing channels is low (a few hundred microseconds), which gives a high degree of utilization even for short transfers. The analysis also shows that when channels are established very frequently, the signaling capacity limits the performance.

The DTM Gigabit Network

DTM is a set of protocols for high-speed networks, 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, fast circuit-switched service. Several DTM networks can be connected into one large network. A prototype implementation and testbed is being constructed.

Resource reservation in DTM

DTM is an optical network with bandwidth reservation and support for dynamic reallocation of bandwidth. DTM is designed for real-time multimedia applications and for high-speed computer communication. DTM provides a service with real-time guarantees: it allows reservation of bandwidth, and has constant delay between two nodes. DTM uses a novel medium-access technique and provides a multicast channel service. The paper describes how resources are reserved in DTM, and describes a DTM prototype implementation to demonstrate that the protocols can be implemented efficiently.<<ETX>>