Sammendrag/Abstract: The motivating vision behind SIPtel is to determine to what extent it is possible to facilitate full-scale deployment of a SIP-based voice over IP (VoIP) service upon UNINETT's production network. To initiate such a determination, the primary goal of Phase 1 within SIPtel project has been to test and evaluate a SIP-based video-conferencing framework for voice over IP (VoIP)...

The commercial deployment of VoIP necessitates the employment of security mechanisms that can assure availability, reliability, confidentiality and integrity. The Session Initiation Protocol (SIP) is considered as the dominant signalling protocol for calls over the Internet. SIP, like other Internet protocols, is vulnerable to known Internet attacks, while at the same time it introduces new sec...

---------------------------------------------------------------------***--------------------------------------------------------------------Abstract The new technology has the ability to transmit a voice over Internet protocol process networks by using an Asterisk PBX.In present day companies are implement to produce a different VoIP products to many features in market.This paper aim is introdu...

Internet Telephony (Voice over Internet Protocol or VoIP) has recently become increasingly popular mainly due to its cost advantages and range of advance services. On the same time, SPam over Internet Telephony (SPIT) referred as unsolicited bulk calls sent via VoIP networks by botnets, is expected to become a serious threat in the near future. Audio CAPTCHA (Completely Automated Public Turing ...

Voice over IP (VoIP) is gaining more popularity in today's communications. The Session Initiation Protocol (SIP) is becoming one of the dominant VoIP signalling protocol[1, 2], however it is vulnerable to many kinds of attacks. Among these attacks, flood-based denial of service attacks have been identified as the major threat to SIP. Even though a great deal of research has been carried out to ...

Push-to-talk (PTT) is a walkie-talkie like service which performs an efficient and instant voice over Internet protocol (VoIP) communication in mobile ad hoc network especially for certain circumstances, such as battle field and earthquake or disaster relief. The authors have designed and implemented the PTT mechanism in ad hoc VoIP network. The PTT server and user agent combined with the pseud...

The Session Initiation Protocol (SIP) protocol is commonly used to establish Voice over IP (VoIP) calls. IETF SIP standards do not specify a secure authentication process thus allowing malicious parties to impersonate other parties or to charge calls to other parties. This paper proposes an extension to the SIP protocol that uses an identity-based authentication mechanism and key agreement prot...

— Voice services over Internet Protocol (VoIP) are nowadays much promoted by telecommunication and Internet service providers. However, the utilization of open networks, like the Internet, raises several security issues that must be accounted for. On top of that, there are new sophisticated attacks against VoIP infrastructures that capitalize on vulnerabilities of the protocols employed for the...

As more and more people are using VoIP softphones in their laptop and smart phones, vulnerabilities in VoIP protocols and systems could introduce new threats to the computer that runs the VoIP softphone. In this paper, we investigate the security ramifications that VoIP softphones expose their host to and ways to mitigate such threats. We show that crafted SIP traffic (noisy attack) can disable...