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In order to enhance the utilization efficiency of network resources and meet the requirements of personalization and the variety of services, traditional TDM technology is replaced by IP. IMS/SIP protocol is adopted when IP PBX is...
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In order to enhance the utilization efficiency of network resources and meet the requirements of personalization and the variety of services, traditional TDM technology is replaced by IP. IMS/SIP protocol is adopted when IP PBX is communicated with the mobile subscribers. However, when the unexpected behaviors occurred during communications, operators require a system, IMSView, to identify the cause. IMSView System is a monitoring and analyzing system for IMS network, whose outstanding characteristics are listed as follows: the capabilities of fully automatic analyzing, expert system for problems analyzing and diagnosing, customized architecture and functionalities, and Web-based analysis results. IMSView System provides a great help to the quality improvement of IMS network. With the IMSView System, maintenance staffs can monitor and analyze IMS network traffic more efficiently. This paper shows the necessity and goals of IMSView System, and the values offered by the system. Also, the system architecture, the system functionalities, and the system operating procedures are introduced.
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Legacy networks, both fixed and mobile, which were originally designed for voice communications, are progressively migrating to new infrastructures that promise to revolutionize the services offered. In this paper, we will cover t...
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Legacy networks, both fixed and mobile, which were originally designed for voice communications, are progressively migrating to new infrastructures that promise to revolutionize the services offered. In this paper, we will cover this new generation of personal communication services, with an emphasis on the family of Internet protocol (IP)-based multimedia subsystem (IMS)-aided infrastructure that relies on the session initiation protocol (SIP). As a benefit, the end users will enjoy a new generation of personal communications services that are accessible anywhere and anytime. These services are directly related to the end users rather than to their diverse devices. It is anticipated that the new deployments of next-generation networks (all-IP based) will accelerate the adoption of the IMS technology.
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IPv6 might solve several of IPv4's shortcomings, but the longer headers and address space add overhead that affects a range of performance metrics for both TCP and UDP. We established a test bed to compare the two protocol stacks ...
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IPv6 might solve several of IPv4's shortcomings, but the longer headers and address space add overhead that affects a range of performance metrics for both TCP and UDP. We established a test bed to compare the two protocol stacks along a set of six performance metrics. We also compared two IPv6 implementations running on Windows 2000 and Solaris 8 using identical hardware and settings. We performed additional tests using different configurations, including a pair of commercial routers that support dual IPv4-IPv6 stacks. While the majority of those results are beyond this article's scope, some of our experiences with the routers raised points that we address here.
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There is currently a high level of consciousness of the importance and impact of formally testing communicating networks. By applying formal description techniques and formal testing approaches, we are able to validate the conform...
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There is currently a high level of consciousness of the importance and impact of formally testing communicating networks. By applying formal description techniques and formal testing approaches, we are able to validate the conformance of implementations to the requirements of communication protocols. In this context, passive testing techniques are used whenever the system under test cannot be interrupted or access to its interfaces is unavailable. Under such conditions, communication traces are extracted from points of observation and compared to the expected behavior formally specified as properties. Since most works on the subject come from a formal model context, they are optimized for testing the control part of the communication with a secondary focus on the data parts. In the current work, we provide a data-centric approach for black-box testing of network protocols. A formalism is provided to express complex properties in a bottom-up fashion starting from expected data relations in messages. A novel algorithm is provided for evaluation of properties in protocol traces. Experimental results on Session Initiation Protocol (SIP) traces for IP Multimedia Subsystem (IMS) services are provided.
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The third-generation partnership project (3GPP) and 3GPP2 have standardized the IP multimedia subsystem (IMS) to provide ubiquitous and access network-independent IP-based services for next-generation networks via merging cellular...
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The third-generation partnership project (3GPP) and 3GPP2 have standardized the IP multimedia subsystem (IMS) to provide ubiquitous and access network-independent IP-based services for next-generation networks via merging cellular networks and the Internet. The application layer Session Initiation Protocol (SIP), standardized by 3GPP and 3GPP2 for IMS, is responsible for IMS session establishment, management, and transformation. The IEEE 802.16 worldwide interoperability for microwave access (WiMax) promises to provide high data rate broadband wireless access services. In this paper, we propose two novel interworking architectures to integrate WiMax and third-generation (3G) networks. Moreover, we analyze the SIP-based IMS registration and session setup signaling delay for 3G and WiMax networks with specific reference to their interworking architectures. Finally, we explore the effects of different WiMax-3G interworking architectures on the IMS registration and session setup signaling delay.
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This article illustrates the related techniques of the hot topic service with advertising in IPTV field. Functions and structure of this service are illustrated. Since Chunghwa Telecom's IPTV products MOD Systems provides a wide r...
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This article illustrates the related techniques of the hot topic service with advertising in IPTV field. Functions and structure of this service are illustrated. Since Chunghwa Telecom's IPTV products MOD Systems provides a wide range of services, the hot topic service aims to provide a content aggregation area which collects services and channels of the same topic, allow users effortlessly to find interesting content in the same topic and improve convenience for users. Furthermore, the advertising system in the hot topic service could promote profit by selling advertisements and help advertisers reach target customers easily.
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This article illustrates the related techniques and the system design of IPTV targeted advertising. The system takes advantage of IPTV in three aspects for advertising: targeted, interactive, and traceable. First, by categorizing ...
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This article illustrates the related techniques and the system design of IPTV targeted advertising. The system takes advantage of IPTV in three aspects for advertising: targeted, interactive, and traceable. First, by categorizing IPTV contents and users, it delivers addressable advertisements to potential customers. Next, it links users to a specific service, category, channel, movie or campaign by interactive advertisements. Then, advertisement views and clicks are collected for analyzing user behavior to adjust scheduling policy. It brings users more relevant information based on click records and advertisers could have accurate reporting about advertising effects. Most important, it helps IPTV provider make profit by selling advertisements easily and convincingly, furthermore, deliver more personalized content to users.
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The services of next generation networks are envisioned to be potentially capable of seamless mobility in spite of the heterogeneity in underlying access technologies. It is undoubted that to accomplish seamless services across he...
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The services of next generation networks are envisioned to be potentially capable of seamless mobility in spite of the heterogeneity in underlying access technologies. It is undoubted that to accomplish seamless services across heterogeneous networking environments gets harder in case of simultaneous mobility. In this article, we propose a mobile-initiated network-executed (MINE) session initial protocol (SIP)-based handover mechanism to facilitate simultaneous mobility in IP multimedia subsystem over heterogeneous accesses. The novelty of the proposed approach is that no changes are required to the existing network infrastructure since handover decision is fully made by the mobile host (MH) and handover execution is performed by a new-added application server called mobility server (MS). When the MH decides to initiate a handover and obtains a new IP address, it will send a SIP Publish message to trigger the MS to carry out the handover execution. With the network-executed design of the MINE, the MS can perform third-party registration for security re-association and third-party call control for session re-establishment in parallel. Moreover, the Master-Slave Determination procedures derived from H.245 are used in the MS to handle fairly the racing conditions resulting from simultaneous mobility such that redundant message flows are eliminated. Mathematical analyses present that the MINE can shorten the handover latency and reduce power consumption, as observed from a comparison with the integrated solution of an optimized macro-mobility mechanism and a receiver-side simultaneous mobility approach.
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In future multimedia systems, seamless access to application services on different devices available to users in their vicinity, will be commonplace. The availability of these services will change as the mobile user moves. Current...
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In future multimedia systems, seamless access to application services on different devices available to users in their vicinity, will be commonplace. The availability of these services will change as the mobile user moves. Current 3G multimedia systems do not support access to multiple applications operating on multiple different devices in context of a session or indeed seamless device session handover. Considering these requirements, the authors outline two multimedia communication platforms which potentially solve this problem. This paper describes a backward compatible architecture based on the widely adopted Session Initiation Protocol (SIP) and also outlines a clean slate approach from ITU-T SG 16 called the Advanced Multimedia System (AMS). For each of these solutions the paper describes in terms of architecture, signalling, and capability negotiation, what are viewed as the most critical functions in future multimedia systems design. The result of this comparison displays the advantages and disadvantages of each approach, and outlines solutions to satisfy challenges of current and future multimedia systems based on the service access requirement in ubiquitous environments. Furthermore, this comparison is used to suggest approaches that are best suited for future multimedia system design.
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The IP multimedia subsystem (IMS) is a basis for a significant new architecture which offers network operators the opportunity to expand their services, by integrating voice and multimedia communications and delivering them into n...
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The IP multimedia subsystem (IMS) is a basis for a significant new architecture which offers network operators the opportunity to expand their services, by integrating voice and multimedia communications and delivering them into new environments with new purposes. Basically, the IMS is an overlay network on top of IP layer that uses Session Initiation Protocol (SIP) as the primary signaling mechanism. SIP works at the application layer in IP networks. It is thus faced to not only the IP-networks security issues, but also to new issues which are related to the SIP protocol directly. Consequently, using IMS bears several new security challenges. This paper presents the most relevant SIP-related security vulnerabilities and threats, and the implementation and simulation test bed to experiment two versions of the SIP Asterisk software to emphasize these threats. The different security mechanisms that can be deployed to overcome the SIP security issues while putting emphasis the most important ones are discussed. Afterwards, the authors propose adaptable solutions to the SIP threats already identified for a specific service (access information from anywhere) in IMS context. Finally, conclusions are drawn and some perspectives are introduced to improve the security of multimedia applications.
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