Despite the features that make Voice over IP so attractive from the standpoint of cost and flexibility of telephone services, businesses will only adopt it once they’ve determined whether, and under what circumstances, the quality of VoIP will be satisfactory to users. This hands-on guide supplies you with all the tools you need for VoIP service quality analysis, including explicit directions for: * designing subjective tests and interpreting results * selecting, extending, and applying speech distortion and multiple effects models * examining call set-up times for IP telephony * determining requirements for multimedia exchanges. Without jargon, or tech talk, Hardy delivers solid information on means of measuring, assessing, and improving VoIP quality. He gives you expert information and hands-on specifics, showing you: * The factors that can create a negative caller experience and how packet switching affects them * What to look for in assessing VoIP quality * How to elicit and interpret user evaluations of voice quality * How to estimate likely user perception of voice quality by objective test and analysis * When and how to apply alternative quality measurement techniques to overcome quality shortfalls.

How to Start a VoIP Business is the first book which explains in plain English how to become a VoIP provider and start different services, based on a VoIP technology. This simple six-stage guide will give you the know-how of launching services, such as mobile VoIP, callback, calling cards, call shops, residential VoIP, virtual PBX, SIP trunking, wholesale transit, call origination and call termination.

"This book is like a good tour guide.It doesn't just describe the major attractions; you share in the history, spirit, language, and culture of the place." --Henning Schulzrinne, Professor, Columbia University Since its birth in 1996, Session Initiation Protocol (SIP) has grown up. As a richer, much more robust technology, SIP today is fully capable of supporting the communication systems that power our twenty-first century work and life. This second edition handbook has been revamped to cover the newest standards, services, and products. You'll find the latest on SIP usage beyond VoIP, including Presence, instant messaging (IM), mobility, and emergency services, as well as peer-to-peer SIP applications, quality-of-service, and security issues--everything you need to build and deploy today's SIP services. This book will help you * Work with SIP in Presence and event-based communications * Handle SIP-based application-level mobility issues * Develop applications to facilitate communications access for users with disabilities * Set up Internet-based emergency services * Explore how peer-to-peer SIP systems may change VoIP * Understand the critical importance of Internet transparency * Identify relevant standards and specifications * Handle potential quality-of-service and security problems

In Securing VoIP Networks, two leading experts systematically review the security risks and vulnerabilities associated with VoIP networks and offer proven, detailed recommendations for securing them. Drawing on case studies from their own fieldwork, the authors address VoIP security from the perspective of real-world network implementers, managers, and security specialists. The authors identify key threats to VoIP networks, including eavesdropping, unauthorized access, denial of service, masquerading, and fraud; and review vulnerabilities in protocol design, network architecture, software, and system configuration that place networks at risk. They discuss the advantages and tradeoffs associated with protection mechanisms built into SIP, SRTP, and other VoIP protocols; and review key management solutions such as MIKEY and ZRTP. Next, they present a complete security framework for enterprise VoIP networks, and provide detailed architectural guidance for both service providers and enterprise users. 1 Introduction 2 VoIP Architectures and Protocols 3 Threats and Attacks 4 VoIP Vulnerabilites 5 Signaling Protection Mechanisms 6 Media Protection Mechanisms 7 Key Management Mechanisms 8 VoIP and Network Security Controls 9 A Security Framework for Enterprise VoIP Networks 10 Provider Architectures and Security 11 Enterprise Architectures and Security

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.

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.