Voice-over-IP (VoIP) systems are increasingly prevalent in our lives. These systems come in a wide variety of flavors such as desktop-based software applications (e.g., Skype [26]), systems that replace public switched telephony network (PSTN) as the primary line voice service (e.g., Vonage [29]), and more recently, VoIP over smart phones. In November 2010, the number of concurrent VoIP users o...

Voice over IP (VoIP) is an important service on the Internet, and privacy for VoIP calls will be increasingly important for many people. Providing this privacy, however, is challenging, as anonymity services can be slow and unpredictable. In this paper, we propose a method for extending onion-routing style anonymity protocols for supporting anonymous VoIP (aVoIP) traffic with reasonable perform...

The issues faced by law enforcement authorities concerning VoIP are very different from that of traditional telephony. VoIP provides strong encryption and a decentralised data­based network. Wiretapping is not applicable to VoIP calls and packet capturing is negated by encryption. New methods are required to collect evidence from systems running VoIP software. This paper ...

Voice over IP (VoIP) technology has many advantages over the traditional Public Switched Telephone Networks. In our project, we realize a simple VoIP software, which mainly consists of a speech collection and playing back part, a speech CODEC and a networking API. For speech collection/playing part, we use the software (C++ class) and the hardware (sound card) to realize its functions. For the ...

Voice over IP (VoIP) and Internet Multimedia Subsystem (IMS) technologies are rapidly being adopted by consumers, enterprises, governments and militaries. These technologies offer higher flexibility and more features than traditional telephony (PSTN) infrastructures, as well as the potential for lower cost through equipment consolidation and, for the consumer market, new business models. Howeve...

Voice over IP is emerging as the new standard in telephony. It inexpensively routes calls worldwide and consumers are embracing it. Inexpensive communications opens the door for unsolicited calls. In this paper we investigate spam in VoIP, discuss properties of the technology that make it vulnerable to spam and propose the use of techniques which impose cost to spammers as an effective approach...

This Magic Quadrant evaluates network service providers (NSPs) that offer international network services to multinational companies (MNCs) with regional networks in Asia/Pacific. The providers focus on data services, especially Internet Protocol (IP) VPNs and, increasingly, Ethernet offerings. Most also offer voice services, especially voice over IP (VoIP) and IP telephony in association with I...