Asynchronous transfer mode security

It is envisioned that asynchronous transfer mode (ATM) will provide scalable and high-performance application-independent security services. The ATM Forum Security Working Group is currently developing its phase one security specification, which defines a number of security services for the ATM user plane and control plane. In addition, mechanisms for carrying security-related messages and required security infrastructure mechanisms are also being defined. These mechanisms will allow an organization to build an ATM network which not only meets its performance objectives, but also its information protection requirements as specified in its site security policy. This article provides an overview of ATM security as specified by the ATM Forum Security Working Group. First, the ATM user and control planes' security services and mechanisms are described. Then the security messaging mechanisms at connection establishment and during the connection lifetime phases are discussed     

Asynchronous transfer mode: the ultimate broadband solution

Asynchronous transfer mode (ATM) is a new telecommunications technology which is being developed and standardised for use with broadband services. This tutorial paper describes the main features of ATM     

Broadband ISDN and asynchronous transfer mode (ATM)

The transfer mode chosen by the CCITT Study Group XVIII Task Group on ISDN Broadband Aspects as the basis of broadband ISDN is called the asynchronous transfer mode (ATM). ATM is a high-bandwidth, low-delay, packetlike switching and multiplexing technique. It is essentially a connection-oriented technique, although it is envisioned as a basis for supporting all services, connectionless as well as connection-oriented. The basic transfer mode concepts are explained. The limits of synchronous transfer mode (ATM) are discussed and reasons for choosing ATM over STM are given. The main technical issues having an impact on the ATM specifications are discussed     

The asynchronous transfer mode: is it a waste of space?

The author discusses asynchronous transfer mode (ATM); a mechanism which permits the creation of new multimedia communication systems. It is the first transfer mode that permits high-speed transmission of real-time services and computer data simultaneously. The introduction of ATM to broadband-ISDN networks is discussed following its approval by the ITU-T. There are unresolved management issues and some of these have important implications for the success of ATM networks     

Networking a la mode [asynchronous transfer mode]

The asynchronous transfer mode (ATM) was developed at the behest of the telecommunications industry, but is being deployed principally within private data networks. In this paper, the author explains this apparent paradox     

Output-buffer switch architecture for asynchronous transfer mode

This paper proposes a new asynchronous transfer mode (ATM) switch architecture for the broadband ISDN. The ATOM switch ATM output-buffer modular switch has a multi-stage network structure, and is highly modular to facilitate capacity expansion. The ATOM switch element is of the output-buffer type with a time-division multiplexed bus and FIFO buffer for each outgoing line. Bit-slice techniques are used to implement the high-speed time-division bus and buffer memories. The output buffer switch has the advantages of no throughput degradation since internal contention is eliminated, and a simple control structure for providing priority and multi-point connections. This paper also deals with switching delay and buffer overflow probabilities for mixed (bursty and non-bursty) traffic.     

Asynchronous transfer of video

Video transfers across IP and ATM networks have received much research attention during the last ten years. Various video services are expected in the future, enabled by the rapid development in video coding and broadband network technology. This article gives an introduction to the issues involved in asynchronous video transfers. Brief overviews of video coding, rate control, and multiplexing, as well as delay, error, and loss control are also given     

Evolution and service requirements of CBR applications on ATM networks

Broadband integrated networks based on asynchronous transfer mode (ATM) technology are being proposed to provide a single integrated access to a variety of services and applications. Constant bit rate services will form an important part of this unified networking solution. In this paper, we identify and describe the relevant aspects related to the implementation of CBR services on ATM. First, we identify two broad categories of potential CBR services for broadband ATM networks. The ATM infrastructure for the identified services is then developed along with the required functionalities of different network elements. Finally, end-to-end performance objectives for the ATM network are determined and verified empirically based on results of laboratory experiments. These performance objectives help us determine the minimum QOS required by the highest class of service category offered by an ATM network.     

ATM DQDB城域网中恒定比特率业务的性能（Ⅱ）;延时分析

本文分析了ＡＴＭ ＤＱＤＢ城域网中恒定比特率业务的时延特性，恒定比特率业务比可变化特率数据业务的优先级高，但两者都采用统一的分组方式进行传输。本文的分析表明，在业务负荷不是非常重的情况下，恒定比特率业务的时延性能还是令人满意的，从而说明了ＡＴＭ ＤＱＤＢ城域网的可行性。     

ATM switching and CPE adaptation in the North Carolina InformationHighway

This article describes the approach which has been used to implement a sector of the information highway throughout the state of North Carolina, with specific attention focused on the functionality of the equipment that comprises the North Carolina Information Highway (NCIH). This implementation of this information highway is based on ATM technology, used in both the switching systems of the network and the customer premises equipment (CPE). The large ATM switching systems provide the extensive number of connections that are predicted for the information highway. Multiple services can also be supported on the ATM switches. The information streams for these different services can all be converted into ATM format using the appropriate ATM adaptation layer for transport through the ATM network. By being able to support multiple services, and transport them across common ATM facilities, the ATM switches offer the NCIH great flexibility in the applications that can be provided to the customers. Use of the ATM technology allows the NCIH to provide the backbone for various services. To provide the distance learning service application and other applications on the NCIH, ATM capabilities are also being provided in CPE on a service multiplexer     

ATM业务量管理及其对ATM交换机设计的影响

ＡＴＭ网络允诺为各种通信业务在同一个通信网络中提供满足各自服务质量的要求的服务。为此，ＡＴＭ网络体系应能提供业务量管理（ｕｔａｆｆｉｃ ｍａｎａｇｅｍｅｎｔ）功能以支持网络业务千差万别的服务质量要求。本文首先阐述了ＡＴＭ论坛（ＡＴＭ Ｆｏｒｍ）中所定义的ＡＴＭ业务种类，它们各自的服务质量要求，以及为保证服务质量所应采用的管理策略。ＡＴＭ交换机是网络中的关键部件，其不同的设计思想对网络中不同业务服务     

ATM in MPLS-based converged core data networks

Services supported by asynchronous transfer mode account for the majority of data and Internet service revenues generated by carrier networks today. This is based on ATM's ability to support high availability services with quality of service. However, the influences of the Internet and a highly dynamic telecommunications market have raised demands for increased flexibility while controlling costs. Therefore, future carrier networks are likely to continue to be based on established technologies, such as ATM, as well as IP. In many cases, this is achieved through maintaining separate ATM and IP core networks, with the IP network supporting Internet services, while the ATM network continues to support guaranteed services such as private lines, broadband access, and video. In some cases, however, it can be advantageous for a carrier to transport segments of their ATM network over their IP network core; for example, to transport ATM traffic currently carried on leased facilities onto an IP network where the service provider owns the facilities. Developments in IP and MPLS-based traffic engineering and QoS may increase the ability of IP-based networks to support ATM services using MPLS. This article provides an overview of approaches enabling a network based on MPLS that naturally supports IP services to also support ATM services. The drivers and requirements for convergence on an IP/MPLS core network are presented, followed by an overview of the different approaches and associated challenges currently being debated in the standards bodies.     

Cells-In-Frames: a system overview

Cells-In-Frames provides an efficient mechanism for integrating both voice and data traffic on an existing campus network that is currently supporting legacy LAN workstations. The solution suggested by this article is to export ATM services within standard LAN frames. Each frame will carry the traffic from one or more ATM cells, but any given LAN frame is associated with only one ATM virtual circuit. The widely different qualities of service required for voice and data traffic is achieved rough the use of AAL1 and AAL5 services. The AAL functions are split appropriately between the workstation and the LAN switch that interfaces to an ATM backbone network. With the use of the Q.2931 signalling protocols defined for ATM, Cells-in-Frames achieves a long-sought-after goal of providing switched networking services to LAN-attached workstations     

Wireless ATM—an overview

This paper sketches the requirements and possibilities of wireless ATM in local area networks. Because of the wide range of services supported by ATM networks, ATM technology is expected to become the dominant networking technology in the medium term for both public infrastructure networks and for local area networks. ATM infrastructure can support all types of services, from time-sensitive voice communications and desk-top multi-media conferencing, to bursty transaction processing and LAN traffic. Extending the ATM infrastructure with a wireless access mechanism meets the needs of those users and customers that want a unified, end-to-end networking infrastructure with high-performance, consistent service characteristics. The paper introduces ATM concepts, discusses the requirements for wireless ATM, in particular for data link control and radio functions. It closes with some notes on development of wireless ATM research systems standardization and spectrum allocations.     

ATM DQDB城域网中恒定比特率业务的性能（Ⅰ）：缓存器设计

ＡＴＭ ＤＱＤＢ城域网可以采用纯ＡＴＭ方式支持综合业务，本文着重研究了ＡＴＭ ＤＱＤＢ城域网中的恒定比特率业务的性能，用一个四维Ｍａｒｋｏｎ链来描述网络中一标记节点的状态，给出了稳态方程和排队长度的幸存函数。本文的分析方法和结果已用于“宽带光纤区域网原理模型”科研项目中的缓存容量设计。     

ATM优先级队列的质量控制

在ＡＴＭ队列中可以采用恰当的优先级方案对具有不同ＱＯＳ指标的业务进行适当的控制。本文提出了一种综合的ＡＴＭ队列管理方案，建立了相应的系统模型，并给出了理论分析和模拟结果，表明这种方案对ＡＴＭ业务的质量控制是有效的。     

ATM for narrowband services

ATM is a broadband fast-packet technology, but its modern technological base should make it less expensive than existing circuit switching systems once economies of scale are reached. The article examines the use of ATM to address the growth of emerging narrowband services such as frame relay. ATM's flexibility in supporting variable rates and levels of service make it an ideal network technology to carry multiple services. While B-ISDN services promise many benefits to users, major issues must be addressed before such services can be available on a large scale. Utilizing ATM as a backbone technology to support the growing capacity needs of emerging narrowband services could facilitate more rapid introduction of ATM into the network infrastructure and speed delivery of future BISDN services     

Granulated broadband network applicable to B-ISDN and PSTN services

A granulated broadband network (GBN) is proposed as an intermediate asynchronous transfer mode (ATM) based platform to be part of an evolution scenario toward B-ISDN. The GBN enables various types of services to be provided including 64-kb/s-based services and broadband services. In the GBN, information is transformed into ATM cells at subscriber line terminals or at customer premises and is transferred through ATM networks; consequently, the cost feasibility of a single-channel cell assembly/deassembly device is a significant factor in economically providing ATM-based conventional services and interworking between STM and ATM networks. Various virtual path capacities with a fine degree of granularity can be provided in a mesh structure between transit modes in the GBN. Economic feasibility studies of the GBN, by simulating on certain large-size real networks in the greater Tokyo area, indicate the possibility of a more than 50% cost reduction in transit networks     

PCS mobility support over fixed ATM networks

As broadband multimedia services and wireless services become popular, there is growing interest in the industry to support ATM over a wireless link, and wireless access to fixed ATM networks. We focus on the internetworking of PCS and ATM networks, in which the air interface remains one of the PCS standards and the backbone is an ATM network with mobility support. It is desirable to minimize the impact of the internetworking and mobility support on the existing/emerging PCS and ATM specifications. A network architecture, a protocol reference model, and signaling protocols for PCS mobility support over fixed ATM networks are described. They are compared against other implementation alternatives and the trade-offs are discussed. Some performance results of the proposed architecture are also presented     

Traffic management for B-ISDN services

A set of asynchronous transfer mode (ATM) bearer service categories, differentiated in terms of quality of service (QOS), that will support the large spectrum of applications expected in broadband integrated services digital networks (B-ISDN) is defined. The evolution of applications and the traffic requirements in B-ISDN/ATM networks are described, and the evolution of network services to address these requirements is discussed. The definition of ATM bearer service categories necessary for the economical support of initial applications and evolution to future B-ISDN services is proposed. The elements of the ATM traffic management strategy to support these service categories are presented