increasing the popularity of sip based services (voip, iptv, ims infrastructure) lead to concerns about its ‎security. the main signaling protocol of next generation networks and voip systems is session initiation protocol ‎‎(sip). inherent vulnerabilities of sip, misconfiguration of its related components and also its implementation ‎deficiencies cause some security concerns in sip based infra...

Voice over Internet Protocol (VoIP) and its underlying Session Initiation (SIP) are widely deployed technologies since they provide an efficient fast means of both voice data communication a single network. However, in spite their advantages, also have security threats due to the inherent vulnerabilities (IP) that can potentially be exploited by hackers. This study introduces novel defense mech...

Spam in Internet telephony (SPIT) networks is likely to become a large problem in the future, as more and more people and companies switch from traditional telephone networks to Voice over IP (VoIP) networks, and as it is easy to spam VoIP users. The goal of this survey paper is to identify techniques to prevent and reduce SPIT. To compare the various SPIT protection techniques, criteria will b...

SPAM, defined as sending unsolicited messages to someone in bulk, might be a problem on SIP open-wide deployed networks. The responsibility for filtering or blocking calls can belong to different elements in the call flow and may depend on various factors. This document defines an authorization based policy language that allows end users to upload anti-SPIT policies to intermediaries, such as S...

Today, the session initiation protocol (SIP) is the predominant protocol for Voice-over-IP (VoIP) signalling. The intention of this paper is to present an overview of VoIP security issues both current and future – focusing on SIP. We start by presenting some fundamental differences between VoIP and the public switched telephone network (PSTN). We then look at specific problems for SIP signallin...

VoIP isn’t secure since it uses the Internet to which many people connect simultaneously. In this paper, we designed and implemented a Wireless VoIP + VPN system with which secure telephone calls are possible using the open project SIP VoIP Gateway, 'Asterisk' and 'OpenVPN'. Key-Words: VoIP, VPN, SIP, Wireless, Security, WiFi

The Session Initiation Protocol (SIP) has been used widely for Voice over IP (VoIP) service because of its potential advantages, economical efficiency and call setup simplicity. However, SIP-based VoIP service basically has two main security issues, malformed SIP message attack and SIP flooding attack. In this paper, we propose a novel mechanism for SIP-based VoIP system utilizing rule matching...

Traditional Voice over Internet Protocol (VoIP) technique is based on client/server architecture. In this paper, we proposed a VoIP architecture for Ad-hoc network that provides users to communicate with each other directly through embedded pseudo SIP server. This architecture will establish a distributed VoIP system. The performance analysis of signal transmission delay will show the advantage...

The implementation of the Session Initiation Protocol (SIP)-based Voice over Internet Protocol (VoIP) and multimedia over MANET is still a challenging issue. Many routing factors affect the performance of SIP signaling and the voice Quality of Service (QoS). Node mobility in MANET causes dynamic changes to route calculations, topology, hop numbers, and the connectivity status between the corres...

Bare PC systems, which run applications without using any operating system (OS) or kernel, are immune to attacks targeting a specific OS. They also perform better than conventional systems due to their reduced overhead. We describe the design, implementation and performance of a SIP user agent (UA) for secure VoIP on a bare PC system. In particular, we discuss SIP functions and message handling...