Your Hands-On Guide to Voice over IP (VoIP) This book was written for the thousands of IT professionals-from CIOs to circuit-switched telecom engineers-who are now responsible for deploying and maintaining secure VoIP networks. The book explains the impact on your VoIP network of PSTN, SIP, H.323, firewalls, NAT, encryption, and the regulatory environment. Coverage includes evaluation, design, integration, and management of VoIP networking components, including IP telephones, gateways, gatekeepers, registration servers, media servers, and proxy servers. Throughout the book, the authors rely on their extensive real-world experience to provide readers with practical applications and solutions. VoIP Isn't Just Another Data Protocol IP telephony uses the Internet architecture, similar to any other data application. However, from a security administrator's point of view, VoIP is different. Understand why. What Functionality Is Gained, Degraded, or Enhanced on a VoIP Network? Find out the issues associated with quality of service, emergency 911 service, and the major benefits of VoIP. The Security Considerations of Voice Messaging Learn about the types of security attacks you need to protect against within your voice messaging system. VoIP and the Public Switched Telephone Network (PSTN) Understand PSTN: what is it, and how does it work? VoIP Communication Architectures See how products like Skype, H.248, IAX, and Microsoft Live Communications Server 2005 The Support Protocols of VoIP Environments Learn the services, features, and security implications of DNS, TFTP, HTTP, SNMP, DHCP, RSVP, SDP, and SKINNY. Securing the Whole VoIP Infrastructure Your guide to Denial-of-Service attacks, VoIP service disruption, call hijacking and interception, H.323-specific attacks, and SIP-specific attacks. Authorized Access Begins with Authentication Learn the methods of verifying both the user identity and the device identity in order to secure a VoIP network. Secure Internet Mail See how S/MIME provides cryptographic security services for electronic messaging applications.