Signalling in voice over IP Networks

Voice signalling protocols have evolved, keeping with the prevalent move from circuit to packet switched networks. Standardization bodies have provided solutions for carrying voice traffic over packet networks while the main manufacturers are already providing products in workgroup, enterprise, or operator portfolio. This trend will accrue in next years due to the evolution of UMTS mobile networks to an “all-IP” environment. In this paper we present the various architectures that are proposed for signalling in VoIP, mainly: H.323, SIP and MGCP. We also include a brief summary about signalling in classical telephone networks and, at the end, we give some ideas about the proposed “all-IP” architectures in UMTS 3G mobile networks.Publicad

Security aspects in voice over IP systems

Security has become a major concern with the rapid growth of interest in the internet. This project deals with the security aspects of VoIP systems. Various supporting protocols and technologies are considered to provide solutions to the security problems. This project stresses on the underlying VoIP protocols like Session Initiation Protocol (SIP), Secure Real-time Transport Procotol (SRTP), H.323 and Media Gateway Control Protocol (MGCP). The project further discusses the Network Address Translation (NAT) devices and firewalls that perform NAT. A firewall provides a point of defense between two networks. This project considers issues regarding the firewalls and the problems faced in using firewalls for VoIP; it further discusses the solutions about how firewalls can be used in a more secured way and how they provide security

TABLE OF CONTENTS

Once you are aware of the benefits and applications of Voice over IP, it is too good to resist. Perhaps that is why vendors are flooding the market with VOIP products and services. The following paper analyzes the various issues in the evolving VOIP technology and the challenges in the development of VOIP products. It then presents the features of few VOIP Products offered by the leaders in this field, how well they handle the issues and som

IPv6 Network Mobility

Network Authentication, Authorization, and Accounting has been used since before the days of the Internet as we know it today. Authentication asks the question, “Who or what are you?” Authorization asks, “What are you allowed to do?” And fi nally, accounting wants to know, “What did you do?” These fundamental security building blocks are being used in expanded ways today. The fi rst part of this two-part series focused on the overall concepts of AAA, the elements involved in AAA communications, and highlevel approaches to achieving specifi c AAA goals. It was published in IPJ Volume 10, No. 1[0]. This second part of the series discusses the protocols involved, specifi c applications of AAA, and considerations for the future of AAA

Impact of a Node mobility in two Mobile WiMAX Networks under different speeds

Mobility is important in wireless network because internet connectivity can only be effective if it is available during the movement of node. Several works have been carried out in performance analysis of node mobility in horizontal handover, but none of those is carried out in multiple networks within the same technology, So this paper analysis the performance of mobile nodes during handover in two WIMAX networks and to measure the performance there are number of parameters available like handover latency, end - to - end delay, MOS value, Throughput, Network Delay, etc. and we have used Network Throughput, Network Delay and MOS val ue which are involved in mobility management procedures

Analysis of voice quality problems of Voice Over Internet Protocol (VoIP)

After its introduction in mid 90s, Voice Over Internet Protocol (VoIP) or IP telephony has drawn much attention. The prospect of cost savings on long distance and international toll calls, the global presence of Internet Protocol (IP), and the trend to converge data networks with voice networks have made VoIP one of the fastest growing telecom sectors. Additionally, the emergence of 3rd Generation (3G) cellular technology which offers high bandwidth will result in the convergence of the Internet and the cellular networks which will further stimulate the growth of VoIP. However, VoIP faces many problems mainly because of the nature of IP networks which were built to transport non-real-time data unlike voice. This thesis analyzes factors affecting the voice quality of VoIP. These factors are delay, jitter, packet loss, link errors, echo and Voice Activity Detection (VAD). Further, implementation suggestions to lessen the effects of these factors are presented and finally, these suggestions are analyzed.http://archive.org/details/analysisofvoiceq109456261First Lieutenant, Turkish ArmyApproved for public release; distribution is unlimited