Найти книгу: "IP Telephony"

IP (internet protocol) Telephony, enabled by softswitches, is going to usher in a new era in telecommunications. By putting voice and data over one IP network, operators can enjoy lower costs and create new, revenue-generating «multimedia» services. This valuable reference offers a comprehensive overview of the technology behind IP telephony and offers essential information to network engineers, designers and managers who need to understand the protocols and explore the issues involved in migrating the existing telephony infrastructure to an IP-based real time communication service. Drawing on extensive research and practical development experience in VoIP from its earliest stages, the authors give access to all the relevant standards and cutting-edge techniques in a single resource. IP Telephony: Deploying Voice-over-IP Protocols: Assumes a working knowledge of IP and networking and addresses the technical aspects of real-time communication over IP. Presents a high level overview of packet media transport technologies, covering all the major VoIP protocols – SIP, H323 and MGCP Details specific strategies to design services for public networks where endpoints cannot be trusted and can be behind firewalls. Explores the problems that may arise from incomplete protocol implementations, or architectures optimized for private networks which fail in a public environment. This amply illustrated, state-of-the art reference tool will be an invaluable resource for all those involved in the practical deployment of VoIP technology.

All you need to know about deploying VoIP protocols in one comprehensive and highly practical reference – Now updated with coverage on SIP and the IMS infrastructure This book provides a comprehensive and practical overview of the technology behind Internet Telephony (IP), providing essential information to Network Engineers, Designers, and Managers who need to understand the protocols. Furthermore, the author explores the issues involved in the migration of existing telephony infrastructure to an IP – based real time communication service. Assuming a working knowledge of IP and networking, it addresses the technical aspects of real-time applications over IP. Drawing on his extensive research and practical development experience in VoIP from its earliest stages, the author provides an accessible reference to all the relevant standards and cutting-edge techniques in a single resource. Key Features: Updated with a chapter on SIP and the IMS infrastructure Covers ALL the major VoIP protocols – SIP, H323 and MGCP Includes a large section on practical deployment issues gleaned from the authors’ own experience Chapter on the rationale for IP telephony and description of the technical and business drivers for transitioning to all IP networks This book will be a valuable guide for professional network engineers, designers and managers, decision makers and project managers overseeing VoIP implementations, market analysts, and consultants. Advanced undergraduate and graduate students undertaking data/voice/multimedia communications courses will also find this book of interest. Olivier Hersent founded NetCentrex, a leading provider of VoIP infrastructure for service providers, then became CTO of Comverse after the acquisition of NetCentrex. He now manages Actility, provider of IMS based M2M and smartgrid infrastructure and applications.

Translates technical jargon into practical business communications solutions This book takes readers from traditional voice, fax, video, and data services delivered via separate platforms to a single, unified platform delivering all of these services seamlessly via the Internet. With its clear, jargon-free explanations, the author enables all readers to better understand and assess the growing number of voice over Internet protocol (VoIP) and unified communications (UC) products and services that are available for businesses. VoIP and Unified Communications is based on the author's careful review and synthesis of more than 7,000 pages of published standards as well as a broad range of datasheets, websites, white papers, and webinars. It begins with an introduction to IP technology and then covers such topics as: Packet transmission and switching VoIP signaling and call processing How VoIP and UC are defining the future Interconnections with global services Network management for VoIP and UC This book features a complete chapter dedicated to cost analyses and payback calculations, enabling readers to accurately determine the short- and long-term financial impact of migrating to various VoIP and UC products and services. There's also a chapter detailing major IP systems hardware and software. Throughout the book, diagrams illustrate how various VoIP and UC components and systems work. In addition, the author highlights potential problems and threats to UC services, steering readers away from common pitfalls. Concise and to the point, this text enables readers—from novices to experienced engineers and technical managers—to understand how VoIP and UC really work so that everyone can confidently deal with network engineers, data center gurus, and top management.

IMS Multimedia Telephony service has been standardized in 3GPP as the replacement of the circuit switched telephony service in cellular networks. The multimedia telephony service consists of several service components such as voice, video and text. ‘IMS Multimedia Telephony over Cellular Systems’ provides a comprehensive overview of the service that will enable enriched telephony for mobile users. Enriched telephony fulfils the user’s desire to communicate in new ways, for example by sharing pictures and video clips. In addition to an overview of the Multimedia Telephony service, the book focuses on the modern media processing methods, which allows the quality of the packet switched voice and video telephony not only to match but also possibly exceed the quality of circuit switched telephony. Such key components as adaptive jitter buffering and adaptation of conversational media are explained in detail. Key features: Detailed description of how Multimedia Telephony sessions are set-up and controlled Analysis showing the capacity and quality of VoIP and Multimedia Telephony in cellular networks Coverage of other IMS services such as PoC specified by 3GPP and OMA Description of suitable QoS and radio bearers for Multimedia Telephony Explanation of the modern radio interface, especially High Speed Packet Access, which is based on concepts such as link adaptation and fast hybrid ARQ The possibilities for the current and future standards covered in this book make it an indispensable resource for engineers, designers and researchers in VoIP, telecommunication companies and universities teaching and conducting research in telecommunications. It will also be of interest to managers needing an in-depth knowledge of the engineering and key issues of this complex technology, and students aspiring to develop a career in this area.