Currently, people can collect information and share resources on the Internet through WiFi. The Voice over Internet Protocol (VoIP) supported by wireless technology has made Internet access more versatile and flexible than before. However, the more sessions established for communication, the longer the transmission delay and the higher the packet dropping rate. In this paper, an improved bandwi...

Changes From the previous version 1) Discussion about interoperation between this profile and AMIS-Digital was deleted. Such a gateway is outside the scope of this document. 2) The Text/Signature body part was dropped in favor of a simpler mechanism for Spoken-Name support. Spoken name will be contained as an additional audio/* segment in a multipart. Work toward Text/Signature will continue in...

The user authentication scheme is a useful mechanism for verifying the legitimacy of a remote user over insecure network environments. Recently, smart card-based user authentication schemes have been used in a wide range of applications, such as Internet commerce, electronic mail system, and voice over Internet protocol. However, most existing authentication schemes cannot protect the privacy o...

A class of special-purpose computers has evolved to provide voice messaging services. These machines generally interface to a telephone switch and provide call answering and voice messaging services. Traditionally, messages sent to a non-local machine are transported using analog networking protocols based on DTMF signaling and analog voice playback. As the demand for networking increases, ther...

In this paper, we analyze the extended real-time Polling Service (ertPS) algorithm in IEEE 802.16e systems, which is designed to support Voice-over-Internet-Protocol (VoIP) services with data packets of various sizes and silence suppression. The analysis uses a two-dimensional Markov Chain, where the grant size and the voice packet state are considered, and an approximation formula for the tota...

This research identi es the problems encountered in transmitting voice over the Internet and proposes approaches to solve these problems. The current Internet is not very suitable for transmitting real-time data because its underlying protocols and switches were only engineered to transmit non-real time data. The problems posed by voice over the Internet are studied by conducting a series of ex...

This paper quantitatively analyzes the maximum UDP (User Datagram Protocol) throughput for two-way flows in wireless string multi-hop networks. The validity of the analysis is shown by the comparison with the simulation and the experiment results. The authors also clarify the difference fundamental characteristics between a one-way flow and a two-way flow in detail based on the simulation resul...

Status of This Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Abstract This specification defines how t...

The Security threats to current circuit switched networks dedicated to a single voice application such as the Public Switched Telephone Network (PSTN) are considered minimal. However, in open environments such as the Internet, conducting an attack on voice applications such as Voice over IP (VoIP) is much simpler. This is because VoIP services such as Session Initiation Protocol (SIP) are using...

This paper focuses on deployment of voice over the Internet for the customers of a global services provider which needed to extend cost-effectively the portfolio of enhanced voice services including unified messaging, post paid and prepaid calling card services along with related validation, billing and payment systems. Key-words: VoIP, Internet, SS7, Compression, QoS