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Journal ArticleDOI

CCITT standardization of network node interface of synchronous digital hierarchy

01 Aug 1990-IEEE Communications Magazine (IEEE)-Vol. 28, Iss: 8, pp 15-20
TL;DR: The main concepts and interfacing and multiplexing techniques for an NNI (network node interface) as set forth in CCITT (International Consultive Committee for Telephone and Telegraph) Recommendations are described in this article.
Abstract: The main concepts and interfacing and multiplexing techniques for an NNI (network node interface) as set forth in CCITT (International Consultive Committee for Telephone and Telegraph) Recommendations are described. The objectives and history of the NNI standardization are reviewed together with concepts, basic requirements, and features of the NNI. The nine-row-based frame structure and the virtual container (VC) concept, which are the main features of the NNI, are introduced. The multiplexing principle and method, the detailed frame structure and overhead, and mapping methods related to the NNI are described. Applications of the NNI in the synchronous network and international interworking are presented. The future application of asynchronous transfer mode (ATM) is discussed. >
Citations
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Patent
28 Jan 2002
TL;DR: In this article, the content of entities for transportation across an existing network are mapped into a series of subframes and are virtually concatenated across the network, each subframe is assigned a sequence indicator, which allows the original entity to be assembled at a remote node.
Abstract: A communications network including nodes which permit networks to be tunnelled across intermediate networks. The present invention has application, in particular, to SDH networks, SONET and OTN. The content of entities for transportation across an existing network are mapped into a series of subframes and are virtually concatenated across the network. Each subframe is assigned a sequence indicator, which allows the original entity to be assembled at a remote node.

50 citations

Journal ArticleDOI
TL;DR: In this article, a low-crosstalk 8/spl times/8 optical matrix switch module has been developed, which achieved a low insertion loss of 10.0 dB, a low cros stalk level of -25.9 dB, and had excellent stability in practical operation.
Abstract: A compact, low-crosstalk 8/spl times/8 optical matrix switch module has been developed. A thermooptic switch chip and driving circuits with TTL interfaces are integrated on a 100-mm/sup 2/ ceramic substrate. It achieved a low insertion loss of 10.0 dB, a low crosstalk level of -25.9 dB, and had excellent stability in practical operation. A photonic intermodule connector for electronic switching systems in the near future is also demonstrated through the use of these optical switch modules. >

38 citations

Book ChapterDOI
TL;DR: A new algorithm is proposed that provides integer solutions, handles non-linear equivalent bandwidths, finds its own paths, and allows for an arbitrary design optimisation criterion and is found to perform equal to or better than an earlier, comparable though more restricted, algorithm.
Abstract: We study dynamically rearrangable end-to-end transport networks by means of SDH/SONET and/or ATM virtual paths. The concept and its advantages are brie y reviewed and we propose a new algorithm for designing such networks. Our algorithm provides integer solutions, handles non-linear equivalent bandwidths, finds its own paths, and allows for an arbitrary design optimisation criterion. It is found to perform equal to or better than an earlier, comparable though more restricted, algorithm. We also put forward a strategy for managing virtual paths in real time. It consists of a repeated cycle of on-line measurement of offered traffics followed by the design and implementation of a new virtual path network. Methods and parameters for traffic measurements and network updating frequency are studied and optimised. Applying the strategy to rearrangeable networks subject to variable traffics in a simulator, we discover considerable gains and a robustness in our parameter settings.

24 citations

01 Sep 1990
TL;DR: A network architecture called Highball and a preliminary design for a prototype, wide-area data network designed to operate at speeds of 1 Gbps and beyond are described, intended for applications requiring high speed burst transmissions.
Abstract: A network architecture called Highball and a preliminary design for a prototype, wide-area data network designed to operate at speeds of 1 Gbps and beyond are described. It is intended for applications requiring high speed burst transmissions where some latency between requesting a transmission and granting the request can be anticipated and tolerated. Examples include real-time video and disk-disk transfers, national filestore access, remote sensing, and similar applications. The network nodes include an intelligent crossbar switch, but have no buffering capabilities; thus, data must be queued at the end nodes. There are no restrictions on the network topology, link speeds, or end-end protocols. The end system, nodes, and links can operate at any speed up to the limits imposed by the physical facilities. An overview of an initial design approach is presented and is intended as a benchmark upon which a detailed design can be developed. It describes the network architecture and proposed access protocols, as well as functional descriptions of the hardware and software components that could be used in a prototype implementation. It concludes with a discussion of additional issues to be resolved in continuing stages of this project.

17 citations

Proceedings ArticleDOI
28 Mar 1993
TL;DR: The joint topology, discrete capacity, and routing problem in a reconfigurable ATM network is formulated as a nonlinear mixed integer programming problem and it is proven that this problem with integrality constraints relaxed can be simplified to a convex programming problem.
Abstract: Reconfiguration capability in asynchronous transfer mode (ATM) networks and its ability to reduce ATM cell losses are studied. An implementation that restricts the transmission of ATM cells of an O-D pair to certain channels in each physical link in a simple path from origin to destination is proposed. The joint topology, discrete capacity, and routing problem in a reconfigurable ATM network is formulated as a nonlinear mixed integer programming problem. It is proven that this problem with integrality constraints relaxed can be simplified to a convex programming problem, providing a method for computing a lower bound on the original problem. An algorithm is developed to solve the nonlinear mixed integer programming problem. In computational experiments, the reconfiguration capability decreased the total cell losses by more than 50%. >

16 citations

References
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Journal ArticleDOI
TL;DR: In this article, the authors discuss aspects of the SONET (synchronous optical network) standards and standardization process, both national and international, that they consider to be of particular interest.
Abstract: The authors discuss aspects of the SONET (synchronous optical network) standards and standardization process, both national and international, that they consider to be of particular interest. Restricting their attention to the standard dealing with rates and formats, they consider the SONET signal hierarchy, overhead channels, multiplexing, STS-1 payload pointer, sub-STS-1 payloads, and optical interface parameters. They include a brief history of the SONET standard and an outline of future work. >

175 citations

Proceedings ArticleDOI
28 Nov 1988
TL;DR: Synchronous equipment using the CCITT standard network node interface (NNI) is being developed, which is expected to simplify the network, reduce its cost, and allow rapid provisioning.
Abstract: Synchronous equipment using the CCITT standard network node interface (NNI) is being developed. The equipment consists of three kinds of modules: a skip-level multiplexer which converts the existing switching and transmission system interfaces to the NNI, a TU-11 (24 CH) cross-connect device, and an STM-N skip-multiplexer with a line terminating function. These modules are implemented mainly with state-of-the-art CMOS VLSI and fiber-optic technologies. The equipment is expected to simplify the network, reduce its cost, and allow rapid provisioning. It is also expected to simplify and improve network maintenance and provide greater system versatility of services. >

22 citations

Proceedings ArticleDOI
27 Nov 1989
TL;DR: A synchronous digital transmission system using the network node interface (NNI) that compiles with CCITT recommendations G.707, G.708, and G.709 to offer device independence for function enhancement and to permit a flexible network.
Abstract: The authors describe a synchronous digital transmission system using the network node interface (NNI) that compiles with CCITT recommendations G.707, G.708, and G.709. To offer device independence for function enhancement and to permit a flexible network, the recommendations are implemented as modules A, B, C, and ADP. Module A is a fiberoptic line terminating multiplexer and a generator. Module B is a CV-11 cross-connect system with NNI. Module C converts the existing lower speed interfaces to NNI. ADP converts NNI to the 100-Mb/s existing interface to make use of the existing facilities. The specifications of each module are given, and field trials are discussed. >

20 citations

Proceedings ArticleDOI
28 Nov 1988
TL;DR: The author introduces basic concepts, technologies and a standard for the network node interface (NNI) for synchronous digital networks and basic requirements for such networks and the NNI are considered.
Abstract: The author introduces basic concepts, technologies and a standard for the network node interface (NNI) for synchronous digital networks. Basic requirements for such networks and the NNI are considered. The concepts of a nine-row-based frame structure and a virtual container, which are fundamental to NNI, are introduced. Detailed NNI structures are described. Practical applications of NNI in synchronous networks and international interworking are considered. The accommodation of the asynchronous transfer mode (ATM) is also discussed. >

18 citations

Proceedings ArticleDOI
28 Nov 1988
TL;DR: Attention is given to optical interconnect, fiber terminal evolution, multipoint configurations, novel services, hybrid networks, enhanced performance, monitoring, and enhanced and integrated OAM.
Abstract: The authors discuss future network architectures and application benefits of SONET networking. Emphasis is placed on networking of existing and potential services, OAM (operations, administration, and maintenance), and SONET, the transport format which permits the realization of such future networks. Attention is given to optical interconnect, fiber terminal evolution, multipoint configurations, novel services, hybrid networks, enhanced performance, monitoring, and enhanced and integrated OAM. >

9 citations