This book provides a detailed overview of security issues and how to solve specific SIP While standards and products for VoIP and SIP services have reached market maturity, security and regulatory aspects of these services is still under discussion. SIP itself only specifies a set of basic security mechanism that includes a subset of the possible security problem. Key Features: It helps the reader to understand the real problem and develop services using VoIP, and to distinguish between a real problem and the general hype of VoIP security Discusses key aspects of the SIP security including authentication, integrity, confidentiality, non-repudiation and signal rate security issues facing real SIP users, and details of the latest theoretical and practical solutions to problems securing Covers Security SIP SIP access, inter-provider of secure communications, media, security, security and VoIP services IMS infrastructure vulnerability and mitigation of Denial-service-attacks and VoIP spam This book will appeal to IT staff involved in spreading and developing VoIP, SIP service users, network engineers, designers and managers.