Enhancements to SIP to prevent abuse of Voice-over-IP services

This paper reviews the IETF proposed enhancements to the Session Initialisation Protocol (SIP) to prevent the abuse of its implementation in Voice-over-IP (VoIP) communication services. We look at some of the benefits and drawbacks of these proposed enhancements to ensure trustworthy SIP message exchange. Many proxies assist in establishing of a SIP session. These proxies may modify the traversing SIP messages during transit by injecting routing, logging and call control headers. Due to the distributed nature of VoIP, this could have various implications. We highlight these and proposes a new mechanism of certifying these changes, allowing communicating parties to audit the committed changes. Our aim is to compliment the suggested enhancements to further secure SIP communication.