In VoIP, proxies are used by end-devices to perform a number of tasks including call setup and routing. Setup and routing is achieved through the exchange of call control messages which are forwarded among all involved proxies as well as the communicating end-devices. This paper will explore the information exchanged in Voice-over-IP (VoIP) call control messages and any possible implications th...

The ubiquity and convergence of mobile telephony and the Internet leads many to believe that future isochronous telephony data will be transported in the form of Voice-over-IP (VoIP) datagrams. This paper investigates the modelling and aggregation of multiple VoIP streams. The relationship between the number of VoIP sources, output link rate and certain teletraffic metrics is investigated. Ther...

VoIP over wireless local area network (WLAN) is an important application of WLAN and gaining more and more attention recently. In this paper, we analyze the maximum number of VoIP calls in WLAN and propose a new call admission control strategy, namely, adaptive transmitting interval call admission control (ATICAC) to enhance VoIP calls in 802.11 WLANs. In ATICAC strategy, Base Station (BS) adap...

Voice over IP (VoIP) services have become prevalent lately because of their potential advantages such as economic efficiency and useful features. Meanwhile, Session Initiation Protocol (SIP) is being widely used as a session protocol for the VoIP services. Many mobile VoIP applications have recently been launched, and they are becoming attractive targets for attackers to steal private informati...

In this paper, an efficient scheduling scheme is proposed to increase the available capacity of VoIP services over Evolved UTRA uplink. On top of the advantages of persistent scheduling, the proposed scheme adaptively share the resources of two VoIP users to get early-termination gain of dynamic scheduler. Through system-level simulations, the performance of the proposed algorithm is evaluated ...

Internet telephony –or Voice over Internet Protocol (VOIP)– has the pote ntial to transform the world of voice communicati ons more profoundl y than anything since the inv ention of the telephon e itself. As tele communications incumbents and a range of new entrants begin rolling out commercial VOIP services, policymakers around the world are grappling with the regulatory implications. In the U...

Energy Efficient in the VoIP broadcast is the main criterion and issue to be maintaining the small package and data as dispensation VoIP (QoS) over MANET environment. Mobile Adhoc network (MANETs) presents a good stage for the fast use of VoIP services in many request scenarios. The energy competence in handset mechanism for the data small package of say in the queue scheme has not been intense...

This study adopted a simulation based network performance analysis to investigate the effects of the application of different voice encoder schemes on QoS of VoIP system ,deployed with UMTS network Through different network simulation experiments using realistic network scenarios in OPNET environment, the results indicated that the choice of suitable voice encoder scheme with a small number of ...

Voice IP (VoIP) over wireless local area network (WLAN) is a topic of great interest in the research arena. To investigate what are the performance limitations in establishing VoIP calls over WLAN networks we performed some simulations. We show in this paper these simulation results in ad-hoc and infrastructure WLAN networks, working under ideal and real conditions. Measures and graphs of packe...

In this paper we develop a methodology to set the VoIP application parameters (voice packet size and dejittering delay) and the UMTS air interface parameters in such a way that the quality of VoIP calls involving a UMTS party is ensured. We use analytical techniques to determine the delay and packet loss contributions of the various transmission stages crossed by the voice packet flow, and the ...