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.

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 newly revised edition of the ground-breaking Artech House bestseller, SIP: Understanding the Session Initiation Protocol gives you a thorough and up-to-date understanding of this revolutionary protocol for call signaling and IP Telephony. The second edition includes brand new discussions on the use of SIP for wireless multimedia communications. It explains how SIP is powerful "rendezvous" protocol that leverages mobility and presence to allow users to communicate using different devices, modes, and services anywhere they are connected to the Internet You learn why SIP has been chosen by the 3GPP (3rd Generation Partnership Program for wireless cell phones) as the core signaling, presence, and instant messaging protocol.

VoIP or Voice Over Internet Protocol is an emerging telecommunication technology that make use of IP network to carry voice just like PSTN (Public Switched Telephone Network) or traditional phones. There are several companies offering low cost and more flexible phones and packages of VoIP systems. Future belongs to VoIP because of its low cost and flexibility and more control.This innovative technology will change the life of people because the dream of video phone is just behind its bars. This book covers the basic architecture, usefulness, challenges and features of the VoIP Phones systems.

Voice over Internet Protocol (VoIP) networks, the technology used to place phone calls through the Internet, suffer from the same security holes as standard IP networks. This book reviews the many possible VoIP attacks, and discusses the best defenses against them.

Voice Over IP (VoIP) phone lines now represent over 50% of all new phone line installations. Every one of these new VoIP phone lines and handsets must now be protected from malicious hackers because these devices now reside on the network and are accessible from the Internet just like any server or workstation.This book will cover a wide variety of the publicly available exploit tools and how they can be used specifically against VoIP (Voice over IP) Telephony systems. The book will cover the attack methodologies that are used against the SIP and H.323 protocols as well as VoIP network infrastructure. Significant emphasis will be placed on both attack and defense techniques. This book is designed to be very hands on and scenario intensive· More VoIP phone lines are being installed every day than traditional PBX phone lines· VoIP is vulnerable to the same range of attacks of any network device· VoIP phones can receive as many Spam voice mails as your e-mail can receive Spam e-mails, and as result must have the same types of anti-spam capabilities

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

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.

The first book published on deploying Voice Over IP (VoIP) products from Nortel Networks, the largest supplier of voice products in the world.This book begins with a discussion of the current protocols used for transmitting converged data over IP as well as an overview of Nortel's hardware and software solutions for converged networks. In this section, readers will learn how H.323 allows dissimilar communication devices to communicate with each other, and how SIP (Session Initiation Protocol) is used to establish, modify, and terminate multimedia sessions including VOIP telephone calls. This section next introduces the reader to the Multimedia Concentration Server 5100, and Nortel's entire suite of Multimedia Communications Portfolio (MCP) products. The remaining chapters of the book teach the reader how to design, install, configure, and troubleshoot the entire Nortel product line.· If you are tasked with designing, installing, configuring, and troubleshooting a converged network built with Nortel's Multimedia Concentration Server 5100, and Multimedia Communications Portfolio (MCP) products, then this is the only book you need. · It shows how you'll be able to design, build, secure, and maintaining a cutting-edge converged network to satisfy all of your business requirements· Also covers how to secure your entire multimedia network from malicious attacks

Put your phone system on your computer network and see the savings See how to get started with VoIP, how it works, and why it saves you money VoIP is techspeak for "voice over Internet protocol," but it could spell "saving big bucks" for your business! Here's where to get the scoop in plain English. Find out how VoIP can save you money, how voice communication travels online, and how to choose the best way to integrate your phone system with your network at home or at the office. Discover how to: Use VoIP for your business or home phone service Choose the best network type Set up VoIP on a wireless network Understand transports and services Demonstrate VoIP's advantages to management