Dynamic synchronous Transfer Mode , or DTM for short, is a network protocol. It provides high-speed networking with top-quality transmissions and the ability to adapt the bandwidth to traffic variations quickly. DTM is designed to be used in Integrated services networks for both distribution and one-to-one communication. It can be used directly for application-to-application communication or as a carrier for higher-layer protocols such as Internet protocol (IP). The internet protocol suite is the set of communications protocols that implement the protocol stack on which the Internet and most commercial networks run. ... Bold text TBold texthe application layer is the seventh level of the seven-layer OSI model. ... It has been suggested that Domain name be merged into this article or section. ... Secure Sockets Layer (SSL) and Transport Layer Security (TLS), its successor, are cryptographic protocols which provide secure communications on the Internet. ... 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Applications that might make use of DCCP include those with timingconstraints on the delivery of data such that reliable in-order delivery, when combined with congestion control, is likely... The Stream Control Transmission Protocol (SCTP) is a transport layer protocol defined in 2000 by the IETF Signaling Transport (SIGTRAN) working group. ... Transport layer protocol designed originally as part of the Plan 9 from Bell Labs operating system and used to carry 9P. Its main features are: Reliable datagram service In-sequence delivery Internetworking using IP Low complexity, high performance Adaptive timeouts The original paper describing IL: [1] Categories: Computer stubs ... In computer networking, the Reliable User Datagram Protocol (RUDP) is a transport layer protocol designed at Bell Labs for the Plan 9 operating system. ... The network layer is level three of the seven level OSI model. ... 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Introduction

Basic principle

In DTM, capacity is allocated to a channel by assigning a number of time slots to it. I.e. it is basically a Time Division Multiplexing (TDM) system. What sets it apart from other TDM systems is the capability to assign any number of time slots to a channel, and also varying this number of slots as user traffic demands. The basic argument for this technique is that it provides a guaranteed quality-of-service (QoS) since resources are physically allocated to the channel and traffic from other channels will have no impact on this channel. TDM is a three-letter acronym that may refer to: Pro Tools TDM, an audio effects plug-in architecture based on Time Division Multiplexing and created by Digidesign for their popular Pro Tools Digital Audio Workstation Time-division multiplexing, a method for sending multiple digital signals along a single telecommunications... The abbreviation QOS could refer to one of several things: Quality of service, a measure of the reliability of a computer network Queen of the South F.C., a Scottish football club Quarterdeck Office Systems, a software company that is now part of Symantec This is a disambiguation page — a...

Switching

The DTM standard also specfies that DTM channels may be switched, which sets it apart from ordinary transmission techniques, such as SDH or SONET. A DTM channel is thus automatically provisioned end-to-end over a general topology network using control signalling. DTM is thus a circuit switched system. The switches are generally Time-Space switches that also has the the guaranteed QoS property, since resources are physically allocated per channel also in the switch. This as opposed to packet or cell based routers/switches, in which the packets and cells are competing for resources and as a result of this competition may have packets or cells delayed or discarded. For packet and cell switches this shared resource allocation mechanism imposes a limit to how high the utilization of a network can be before the QoS get un-acceptably low. In DTM network there is no such shared resource allocation, implying that a network theoretically can be loaded to 100% and still have guaranteed QoS for its services. Real utilization becomes thus more a question of adapting the network topology and link capacities to the actual traffic matrix than to accomodating for QoS. Synchronous Optical Networking, commonly known as SONET, is a standard for communicating digital information over optical fiber. ... Synchronous Optical Networking, commonly known as SONET, is a standard for communicating digital information over optical fiber. ... In telecommunication, the term circuit switching has the following meanings: 1. ...

Why not Packet/Cell switching?

Packet/cell networks are good (actually were designed) to perform statistical multiplexing. This means that when different packet streams in a switch or router arrives to a common outgoing link they are buffered until there are resources free on this link. This makes it possible to utilize the outgoing link to a high degree at the cost of varying delays. This is a great property for best effort traffic, for which no QoS level is specified. However with the increasing demand for streaming media with tight QoS requirements, this paradigm falls short. Streaming traffic is not particulary statistical in its nature and is better served by a fixed resource allocated channel end-to-end.

It is to this kind of streaming media services the DTM technology is typically applied. i.e for video or audio services. This does not excludes IP traffic which can gain from being served by a guaranteed QoS transport, especially if the IP traffic contains video/audio. Indeed there are under-going efforts for adapting IP and Ethernet technologies for streaming media (see for example Professional video over IP). These efforts aims in much to emulate the basic principles for DTM with rather complicated mechanisms. Professional video over IP systems use some existing standard video codec to reduce the program material to a bitstream (such as an MPEG-2 transport stream), and then to use an Internet Protocol (IP) network to carry that bitstream encapsulated in a stream of IP packets. ...

DTM is specified in ETSI recommendations ETSI ES 201 803. The European Telecommunications Standards Institute (ETSI) is a standardization organization of the telecommunications industry (equipment makers and network operators) in Europe, with worldwide projection. ...