Internet Telephony is realized by way of instant messaging and the transmitted data are voice rather than text packets, therefore it is more difficult to identify and/or prevent Spam over Internet Telephony (SPIT) than SPAM  junk e-mail. With the rising popularity of Voice over IP (VOIP), SPIT becomes a serious issue on security nowadays. This paper proposed an effective SPIT defense system, w...

Interworking of Voice over IP (VoIP) network with traditional Public Switched Telephone Networks (PSTN) is essential for wide adoption of VoIP services. Telephony gateways act as interface between PSTN and IP telephony networks. These gateways use Telephony Gateway REgistration Protocol (TGREP) to advertise their resource information to Location Servers which are responsible for routing calls t...

Unsolicited emails, more commonly known as spam, have plagued the use and efficiency of email since its inception. With the introduction of ungoverned cheap voice communications, such as IP telephony, spam over telephony (SPIT) and its prevention is set to dominate and drive whether the technology is widely adopted or not. A possible example of voice spam schemes includes the use of Interactive...

SPam over Internet Telephony (SPIT) is a rising IP voice telephony threat. Voice over IP enables the transmission of telephone calls over the Internet, as opposed to plain old telephone service. Internet Telephony essentially means low-cost phone calls, i.e. a clear benefit for both consumers and businesses, which may also lead to cheap methods of mass advertising. Still, industry observers war...

Voice-over-IP (VoIP) telephony becomes more and more popular in the wired Internet because of easy-to-use applications with high sound quality like Skype. UMTS operators promise to offer large data rates which should also make VoIP possible in a mobile environment. However, the success of those application strongly depends on the user perceived voice quality. In this paper, we therefore analyze...

IEEE 802.11 wireless local area networks (WLANs) have become an increasingly popular user access technology and a flexible alternative to wired access. WLANs are now appearing not only as wireless extensions in private company networks, but also in homes and at public hot-spots. An attractive concept would be to use these WLAN access networks for public mobile telephony, but in order to accompl...

This memo defines a portion of the Management Information Base (MIB) module for use with network management protocols in the Internet community. In particular, it describes a set of managed objects that are used to manage Telephony Routing over IP (TRIP) devices.

Voice over IP (VoIP) is transporting speech signals over IP network. What makes VoIP challenging is IP network is not designed to serve for real time applications. Real-time aspects of the conversation must be respected; the overall delay between both ends of the conversation should be low to avoid irritably long gaps of silence. This of course should be addressed differently than the broadcast...

For Internet telephony systems, it is necessary to establish a connection between a caller and recipient using the Internet Protocol (IP) address before actual voice communication can take place. A problem of dynamic IP addressing arises when the connection to the Internet is made through an Internet Service Provider (ISP) since the IP address is dynamically allocated only at connection time. T...

In the early eighties, a communications protocol was created that allowed the research community to send data anywhere in the world using packet switching networks. This protocol became known as TCP/IP and ultimately resulted in the creation of the revolutionary Internet. TCP/IP actually refers to a suite of different protocols but, at its core, there exists the fundamental protocol commonly re...