"A system administrator's guide to VoIP technologies"--Cover.

Understand how new network technologies impact VoIP! Voice over Internet Protocol (VoIP) is revolutionizing the way people communicate – both in the corporate world and in personal life. The enormous success of VoIP has led to its adoption in a wide range of networking technologies. Each network technology has its unique features and poses distinct challenges for the performance of VoIP. VoIP: Wireless, P2P and New Enterprise Voice over IPdescribes the issues arising in the deployment of VoIP in an emerging heterogeneous network environment. Along with a brief overview of the concepts, protocols, algorithms, and equipment involved in realizing VoIP, this book focuses on two areas: quality and performance issues in deploying VoIP over various network settings, and the new mechanisms and protocols in these emerging networks to assist the deployment of VoIP. VoIP: Wireless, P2P and New Enterprise Voice over IP: Discusses the basics of VoIP, VoIP codecs and VoIP Protocols including SIP and H.323. Details new technologies such as P2P technology, VoWiFi, WiMax, and 3G Networks. Explains the QoS issues arising from deploying VoIP using the new technologies. Solves the performance issues that arise when VoIP is deployed over different network technologies. This book is an invaluable resource for professional network engineers, designers, managers, researchers, decision makers and project managers overseeing VoIP implementations. Market analysts, consultants, and those studying advanced undergraduate and graduate courses on data, voice and multimedia communications will also find this book insightful.

This book presents a review of the latest advances in speech and video compression, computer networking protocols, the assessment and monitoring of VoIP quality, and next generation network architectures for multimedia services. The book also concludes with three case studies, each presenting easy-to-follow step-by-step instructions together with challenging hands-on exercises. Features: provides illustrative worked examples and end-of-chapter problems; examines speech and video compression techniques, together with speech and video compression standards; describes the media transport protocols RTP and RTCP, as well as the VoIP signalling protocols SIP and SDP; discusses the concepts of VoIP quality of service and quality of experience; reviews next-generation networks based on the IP multimedia subsystem and mobile VoIP; presents case studies on building a VoIP system based on Asterisk, setting up a mobile VoIP system based on Open IMS and Android mobile, and analysing VoIP protocols and quality.

More and more businesses today have their receive phone service through Internet instead of local phone company lines. Many businesses are also using their internal local and wide-area network infrastructure to replace legacy enterprise telephone networks. This migration to a single network carrying voice and data is called convergence, and it's revolutionizing the world of telecommunications by slashing costs and empowering users. The technology of families driving this convergence is called VoIP, or Voice over IP. VoIP has advanced Internet-based telephony to a viable solution, piquing the interest of companies small and large. The primary reason for migrating to VoIP is cost, as it equalizes the costs of long distance calls, local calls, and e-mails to fractions of a penny per use. But the real enterprise turn-on is how VoIP empowersbusinesses to mold and customize telecom and datacom solutions using a single, cohesive networking platform. These business drivers are so compelling that legacy telephony is going the way of the dinosaur, yielding to Voice over IP as the dominant enterprise communications paradigm. Developed from real-world experience by a senior developer, O'Reilly's Switching to VoIP provides solutions for the most common VoIP migration challenges. So if you're a network professional who is migrating from a traditional telephony system to a modern, feature-rich network, this book is a must-have. You'lldiscover the strengths and weaknesses of circuit-switched and packet-switched networks, how VoIP systems impact network infrastructure, as well as solutions for common challenges involved with IP voice migrations. Among the challenges discussed and projects presented: building a softPBX configuring IP phones ensuring quality of service scalability standards-compliance topological considerations coordinating a complete system ?switchover? migrating applications like voicemail and directoryservices retro-interfacing to traditional telephony supporting mobile users security and survivability dealing with the challenges of NAT To help you grasp the core principles at work, Switching to VoIP uses a combination of strategy and hands-on "how-to" that introduce VoIP routers and media gateways, various makes of IP telephone equipment, legacy analog phones, IPTables and Linux firewalls, and the Asterisk open source PBX software by Digium.You'll learn how to build an IP-based or legacy-compatible phone system and voicemail system complete with e-mail integration while becoming familiar with VoIP protocols and devices. Switching to VoIP remains vendor-neutral and advocates standards, not brands. Some of the standards explored include: SIP H.323, SCCP, and IAX Voice codecs 802.3af Type of Service, IP precedence, DiffServ, and RSVP 802.1a/b/g WLAN If VoIP has your attention, like so many others, then Switching to VoIP will help you build your own system, install it, and begin making calls. It's the only thing left between you and a modern telecom network.

Once a guest on telephone lines, the Net now threatens a takeover of its host's principal function: voice-to-voice communications. For intrabusiness use or as a public system, Internet-based telephony can be a real money-saver - or money-maker. In Voice Over IP Networks, you'll learn everything you need to: transmit real-time voices over the Internet; understand the technology and its costs; compare leading vendors and their Internet telephony products - 3Com, Motorola, Lucent, VocalTec, Vienna Systems, Nuera Communications, and more; evaluate advantages of the IPv6 and IPv4 protocols; use RSVP, RTSP, IP Multicast, SONET, ATM, and other technologies for telephony; apply Codecs to voice digitization; emulate T1/E1 trunks; implement a system with appropriate standards; and anticipate trends and new products from innovative companies such as QWest.

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.

Im Mittelpunkt der Diskussion stehen hier existierende und neue Technologien für die Vermittlung von Sprachverkehr über das Internet Protocol (IP). - bis vor kurzem stammte der Datenverkehr über Kommunikationsnetzwerke größtenteils aus herkömmlich vermittelten Telefonverbindungen - zukünftig wird dieser Sprachverkehr durch ein riesiges Volumen paketvermittelter Daten (Text- und Audiodateien, Streaming Video usw.) weit in den Schatten gestellt; Telefongespräche werden dann über Internetprotokolle vermittelt - hier erhalten Sie eine detaillierte Einführung in den Aufbau eines effizienten VoIP-Netzwerkes - erläutert Prototyping und Leistungsmessung in solchen Netzwerken - besprochen werden auch Aspekte des Quality-of-Service (QoS)