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Communications Magazine, IEEE

Issue 4 • Date April 2000

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Displaying Results 1 - 15 of 15
  • Internet telephony [Guest Editorial]

    Publication Year: 2000 , Page(s): 44 - 46
    Cited by:  Papers (1)
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    Freely Available from IEEE
  • Integrated management architecture for IP-based networks

    Publication Year: 2000 , Page(s): 48 - 53
    Cited by:  Papers (3)  |  Patents (2)
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    IP telephony will bring about a dramatic change in the way IP services are planned, provisioned, managed, and billed. In order to build and retain a strong customer base for these new services, service providers need to meet, if not exceed, the customer expectations set by today's traditional voice services. Acceptance of IP telephony will depend on the quality and efficiency with which service providers offer, deliver, and manage IP services. Installation, configuration, and activation must be rapid and error-free. Furthermore, customers will want direct control over the reconfiguration of services and real-time visibility into the impact change has on their operating costs. Once the service is activated, customers will want the provider to guarantee service quality as defined by industry standards. Corporate customers in particular will need to be assured that the provider is proactively monitoring performance to avoid problems and providing them visibility into the performance data collected. This article discusses an integrated management support system for IP-based networks illustrating the functions needed to support the unique challenges of managing VoIP services. An example of a service management system is also described. View full abstract»

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  • Active, programmable, and mobile code networking [Guest editorial]

    Publication Year: 2000 , Page(s): 104
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    Freely Available from IEEE
  • Active distributed management for IP networks

    Publication Year: 2000 , Page(s): 114 - 120
    Cited by:  Papers (7)
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    We argue that a management platform for the future Internet has to be inherently distributed and programmable. This motivates us to introduce a new management architecture, named active distributed management, which exploits the active network and mobile agent paradigms and provides the properties of distributed control and programmability inside the network. We realize the ADM architecture as a management middleware composed of several layers. In order to facilitate the development of efficient and correct programs, these layers include patterns for distributed algorithms that are typical for management applications and a set of building blocks for constructing management programs. First results of an ADM prototype system are presented. View full abstract»

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  • Building blocks for IP telephony

    Publication Year: 2000 , Page(s): 88 - 94
    Cited by:  Papers (5)  |  Patents (1)
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    Convergence between the existing telephone networks and data transfer over the Internet not only demands that new software be written to handle telephony applications which span both networks, but also makes new and innovative applications possible. Rather than writing these applications from the ground up, it would be helpful to have a relatively high-level API on which to prototype new applications. In this article we describe a set of Java packages developed at Cornell University to accomplish this purpose. The software's name is ITX; it is available for download at no charge, and includes sample applications and documentation View full abstract»

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  • Internet telephony: services, technical challenges, and products

    Publication Year: 2000 , Page(s): 96 - 103
    Cited by:  Papers (37)  |  Patents (1)
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    The rapid proliferation of the Internet has given rise to a strong interest in carrying telephony over the Internet. Because the Internet supports data communications, a range of other services can be bundled together with Internet telephony. The Internet, however, was designed for non-real-time data communications, and hence it poses several technical challenges that must be overcome before the Internet can be successfully used for carrying telephone services. This article discusses new services we can expect from Internet telephony, the technical challenges and solutions, and the emerging products that promise to support Internet telephony View full abstract»

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  • Secure quality of service handling: SQoSH

    Publication Year: 2000 , Page(s): 106 - 112
    Cited by:  Papers (6)  |  Patents (2)
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    Proposals for programmable network infrastructures, such as active networks and open signaling, provide programmers with access to network resources and data structures. The motivation for providing these interfaces is accelerated introduction of new services, but exposure of the interfaces introduces many new security risks. We describe some of the security issues raised by active networks. We then describe our secure active network environment (SANE) architecture. SANE was designed as a security infrastructure for active networks, and was implemented in the SwitchWare architecture. SANE restricts the actions that loaded modules can perform by restricting the resources that can be named; this is further extended to remote invocation by means of cryptographic credentials. SANE can be extended to support restricted control of quality of service in a programmable network element. The Piglet lightweight device kernel provides a “virtual clock” type of scheduling discipline for network traffic, and exports several tuning knobs with which the clock can be adjusted. The ALIEN active loader provides safe access to these knobs to modules that operate on the network element. Thus, the proposed SQoSH architecture is able to provide safe, secure access to network resources, while allowing these resources to be managed by end users needing customized networking services. A desirable consequence of SQoSH's integration of access control and resource control is that a large class of denial-of-service attacks, unaddressed solely with access control and cryptographic protocols, can now be prevented View full abstract»

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  • Real-time multimedia over ATM: RMOA

    Publication Year: 2000 , Page(s): 82 - 87
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    RMOA is a new ATM Forum standard addressing the transport of H.323 VoIP traffic over ATM-based Internet backbones. It defines a new H.323 gateway devised to carry H.323 real-time media streams by taking advantage of the quality of service features of ATM. The approach is extremely efficient in that it reduces the protocol overhead on the ATM transport View full abstract»

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  • QoS enabled voice support in the next generation Internet: issues, existing approaches and challenges

    Publication Year: 2000 , Page(s): 54 - 61
    Cited by:  Papers (15)  |  Patents (1)
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    The Internet is under rapid growth and continuous evolution in order to accommodate an increasingly large number of applications with diverse service requirements. In particular, Internet telephony, or voice over IP is one of the most promising services currently being deployed. Besides the potentially significant cost reduction, Internet telephony can offer many new features and easier integration with widely adopted Web-based services. Despite these advantages, there still exist a number of barriers to the widespread deployment of Internet telephony. The most prominent one, however, is how to ensure the QoS needed for voice conversation. The purpose of this article is to survey the state-of-the-art technologies in enabling the QoS support for voice communications in the next-generation Internet. In this article, we first review the existing technologies in supporting voice over IP networks, including the basic mechanisms in the IETF Internet telephony architecture and ITU-T H.323-related Recommendations. We then discuss the IETF QoS framework, specifically the Intserv and Diffserv framework. Finally, we present two leading companies' (Cisco and Lucent) solutions to offering IP telephony services as examples to illustrate how real systems are implemented View full abstract»

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  • VoIP mobility in IP/cellular network internetworking

    Publication Year: 2000 , Page(s): 70 - 75
    Cited by:  Papers (1)  |  Patents (7)
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    This article explores VoIP mobility in the context of IP and cellular networks interworking. ITU-T Rec. H.323 gateways provide the interconnection between IP networks and switched circuit networks. They allow a call originating from an SCN phone to be transmitted over an IP network to an H.323 terminal, or bridged to another SCN phone. While H.323 provides interoperability with other SCN terminals, the major efforts have been focused on IP/wired SCN (PSTN, ISDN, etc.) interworking. In this article we discuss the challenges associated with the interworking between IP networks and cellular networks through H.323 gateways, and propose an innovative approach using the existing call transfer supplementary service to provide VoIP mobility in the H.323 IP telephony networks. The proposed approach uses existing components in the H.323 standard, thereby allowing VoIP mobility service in hybrid IP/cellular networks to be a value-added feature in the existing H.323-compliant Internet telephony systems View full abstract»

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  • Performance evaluation of the architecture for end-to-end quality-of-service provisioning

    Publication Year: 2000 , Page(s): 76 - 81
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    Real-time communications services over the Internet need a new architecture to meet their required quality. From a viewpoint of quality of service provisioning architecture, the Internet can mainly be divided into three types of subnetworks: domain networks, access networks, and stub networks. In this article we focus on issues arising in the former two networks for end-to-end QoS provisioning. First, the access networks are of rather low-speed links, so delay is still of major concern. We examine the statistical delay bound through numerical results derived from our analysis. Schemes to reduce delay are proposed, and their performance is evaluated. Next, domain networks are likely to be of very high-speed links, which can accommodate a huge number of voice flows of low bit rates. Thus, effective flow management will be of major concern because per-flow management is a very costly proposition. Therefore, we pay attention to a flow aggregation scheme, and evaluate its performance by analyzing its blocking probability View full abstract»

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  • Compensating for moderate effective throughput at the desktop

    Publication Year: 2000 , Page(s): 128 - 135
    Cited by:  Patents (16)
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    This article presents the design and development of a networking system architecture targeted to support high-speed TCP/IP communication over ATM. The discussed architecture has been developed in the form of an integrated system which incorporates state-of-the-art software and hardware subsystems, and an OC-12c ATM adapter (622 Mb/s). Moreover, the design of this embedded system has been based on the Chorus real-time operating system, which, in turn, hosts an accelerated TCP/IP protocol stack over ATM. Furthermore, the embedded system board has been developed according to the PCI specification to easily be plugged into a host platform. In addition, the OC-12c ATM adapter subsystem has been designed and developed in order to also be plugged into the same host. The developed architecture has proven very efficient and reliable, providing high-throughput and low-latency bulk data communications. The measured performance on an OC-3c-based (155 Mb/s) testbed has shown that an optimally implemented TCP/IP stack, hosted by a real-time kernel and coupled with an ATM adapter, offers a robust desktop platform for high-speed end-to-end communications. The main feature of the accelerated TCP/IP protocol stack is the out-of-band processing of control and data information. The protocol accelerator embedded system processes the TCP/IP headers and accomplishes checksum computations, while data is transferred from the host's user memory space directly to the network. Finally, for validation purposes, the prototype system has been incorporated in an existing networking infrastructure targeted to support mass storage applications View full abstract»

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  • Active routing for ad hoc networks

    Publication Year: 2000 , Page(s): 122 - 127
    Cited by:  Papers (10)  |  Patents (3)
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    Ad hoc networks are wireless multihop networks whose highly volatile topology makes the design and operation of a standard routing protocol hard. With an active networking approach, one can define and deploy routing logic at runtime in order to adapt to special circumstances and requirements. We have implemented several active ad hoc routing protocols that configure the forwarding behavior of mobile nodes, allowing data packets to be efficiently routed between any two nodes of the wireless network. Isolating a simple forwarding layer in terms of both implementation and performance enables us to stream delay-sensitive audio data over the ad hoc network. In the control plane, active packets permanently monitor the connectivity and setup, and modify the routing state View full abstract»

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  • iGSM: VoIP service for mobile networks

    Publication Year: 2000 , Page(s): 62 - 69
    Cited by:  Papers (8)  |  Patents (3)
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    This article proposes iGSM: a voice-over-IP value-added service for the mobile network. The iGSM service provides user mobility to subscribers, which allows them to use either GSM handsets or H.323 terminals (IP phones or PCs) to access telecommunications services. We describe how the iGSM registration, deregistration, and call delivery procedures can be implemented without modifying the GSM network. We study how the tromboning effect in the standard GSM system can be avoided when accessing the IP network. Then we investigate the misrouting problem caused by user mobility View full abstract»

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  • Opening up networks with JAIN Parlay

    Publication Year: 2000 , Page(s): 136 - 143
    Cited by:  Papers (9)  |  Patents (7)
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    The desire for new business growth has been a major driving force towards the development of open network APIs, such as the Parlay API, within telecommunications networks. The Parlay API enables both third parties (external companies, operating outside the security domain of the network operator) and network operators to build new applications that rely on real-time control of network resources. The Java APIs for integrated networks (JAINTM) Community is defining a Java version of the Parlay API to bring the benefits of the Java language to the Parlay API, and to promote industry-wide adoption of the Parlay API. This article describes the background and rationale behind the work of the Parlay Group, together with the characteristics, structure, and capabilities of the Parlay API. The benefits that Java and the JAIN Community bring to the Parlay API are then explored. A technical overview of the Java version of the Parlay API, referred to as the JAIN Parlay Edit Group API, is given and illustrated using example sequence diagrams. The article concludes by taking a look at what additional features may be added to the API and the implementation activities that lay ahead View full abstract»

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Aims & Scope

IEEE Communications Magazine covers all areas of communications such as lightwave telecommunications, high-speed data communications, personal communications systems (PCS), ISDN, and more.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Osman Gebizlioglu
Huawei Technologies