Voip Research Papers - Academia.edu (original) (raw)

In satellite networks, voice over IP performance is degraded by long delays and low bandwidth. Both call setup time and quality of service (QoS) for voice calls are affected. Separate studies have been undertaken for these performance... more

In satellite networks, voice over IP performance is degraded by long delays and low bandwidth. Both call setup time and quality of service (QoS) for voice calls are affected. Separate studies have been undertaken for these performance metrics. In this paper, we have carried out experiments using different voice codecs to evaluate SIP call setup time and QoS parameters together.

Este artigo apresenta um estudo da utilização do IPSec para garantir a seguran¸ca das comunicações Voz sobre IP em ambientes de comunicação sem fio. Nós investigamos e quantificamos o impacto dos mecanismos de segurança oferecidos pelo... more

Este artigo apresenta um estudo da utilização do IPSec para garantir a seguran¸ca das comunicações Voz sobre IP em ambientes de comunicação sem fio. Nós investigamos e quantificamos o impacto dos mecanismos de segurança oferecidos pelo IPSec ao tráfego multimídia e selecionamos configurações otimizadas para redes 802.11b e Bluetooth.

Depuis quelques années, la technologie VoIP commence à intéresser les entreprises, surtout celles de service comme les centres d’appels. La migration des entreprises vers ce genre de technologie n’est pas pour rien.

Long lasting Ethernet standards have grown beyond traditional LAN networks through MAN to WAN environment, where it has become the technology which many providers use for developing convergent networks that transport new generation... more

Long lasting Ethernet standards have grown beyond traditional LAN networks through MAN to WAN environment, where it has become the technology which many providers use for developing convergent networks that transport new generation services, such as triple-play widely deployed everywhere – from airports and hotels to large cruise ships. The question of network suitability for providing various communication services has to be considered in practice, especially in case of large ships, as the content of traffic is very diverse with exceptionally variable intensity. Under such specific circumstances for ships theoretical models cannot be directly applied. Rather, network design and implementation depend on practical preliminary test results and analysis. To this end, the out-of-service simulation of either network or user equipment was done according to the RFC 2544 recommendation by means of a smart test device that generates the appropriate test traffic over the Ethernet link from a ...

Salah satu model alat telekomunikasi yang handal pada saat terjadi bencana adalah perangkat radio komunikasi. Perangkat radio dengan model Handy Talky, memiliki kemampuan jarak komunikasi yang terbatas. Dengan menggembangkannya menjadi... more

Salah satu model alat telekomunikasi yang handal pada saat terjadi bencana adalah perangkat radio komunikasi. Perangkat radio dengan model Handy Talky, memiliki kemampuan jarak komunikasi yang terbatas. Dengan menggembangkannya menjadi RoIP (Radio Over IP) maka sistem telekomunikasi radio tersebut di tumpangkan pada sistem VoIP agar sistem telekomunikasi radio menjadi lebih global dan mampu mengatasi masalah interoperabilitas dalam masalah telekomunikasi secara umum dan sistem telekomunikasi tanggap bencana. Penelitian ini meneliti tingkat kehandalan dari RoIP (Radio Over IP) yang terimplementasi pada sistem komunikasi tanggap bencana. Pengujian meliputi sistem VOX/Switcher, Packet Loss dan Delay terhadap penggunaan CODEC dan jumlah pengguna serta kualitas internet mobile dari beragam provider yang mampu di gunakan untuk sistem RoIP.

The various convergent technologies nowadays in computer infrastructure, impose an additional burden on existing networks, the need to save technical and budgetary resources, lead companies and public agencies to verify the existence of... more

The various convergent technologies nowadays in computer infrastructure, impose an additional burden on existing networks, the need to save technical and budgetary resources, lead companies and public agencies to verify the existence of means of better utilization of the infra-structured network, in order to provide Integrated services (IntServ) and / or differentiated (DifServ), causing all or almost all the gain of a structure that required time and financial resources to be assembled. In view of such a scenario, the implementation of VoIP (voice over IP) technologies is shown as not only an alternative but a premise for resource utilization, cost reduction and control of large-scale communications within an organization. The objective of this work is to demonstrate the installation of the 3CX tool (formerly ELASTIX) compiled in Debian / LINUX operating system, its applications and implications in small, medium and large companies and bodies, aiming to be not only an alternative but a service initiative Differentiated technology that converged networks offer us.

This paper discusses the issue of how to obtain Quality of Service (QoS) for the new applications (Multimedia, VoIP, ...) over IP networks. QoS principles and parameters (Delay, jitter, ...) are discussed together with the architectures,... more

This paper discusses the issue of how to obtain Quality of Service (QoS) for the new applications (Multimedia, VoIP, ...) over IP networks. QoS principles and parameters (Delay, jitter, ...) are discussed together with the architectures, frameworks, protocols and mechanisms being proposed for obtaining a guaranteed application support over the Internet and private IP networks.

Session Initiation Protocol (SIP) is a standard protocol for multimedia as a product of Internet Engineering Task Force (IETF) and has been used as a standard VoIP. This protocol combines mobile technology and the world internet. A... more

Session Initiation Protocol (SIP) is a standard protocol for multimedia as a product of Internet Engineering Task Force (IETF) and has been used as a standard VoIP. This protocol combines mobile technology and the world internet. A session in SIP networks can be voice calls, e-mails, text messages or video streaming. The advantages of SIP is a network operator can use to control all of communication in the network, not just the voice. SIP protocol comes from the Simple Mail Transport Protocol (SMTP) and Hypertext Transport Protocol (HTTP). In this research Voice over IP service (VoIP) SIP on the local network using a Graphical Network Simulator (GNS3) analyzed by observing the Quality of Service (QoS) that is the value of the delay, jitter, packet loss and throughput with Wireshark uses that standard G. 114. There one model of the network using OSPF routing and simulation C7200 Cisco routers and type of communication network connecting cable.
Keywords : VOIP, QoS, OSPF

Histoire de la mise en place d'un des premiers IP-PBX informatique, en remplacement d'un central PBX classique. Comment le monde informatique, s'est invité et finalement imposé au monde Telecom. Nous sommes en 2001, à Genève.

Telecommunications in recent years has been undergoing a rapid growth all over the world. Prominent among the advancements of telecommunication is the evolution of modern converged network that provides the trio of data, voice and video... more

Telecommunications in recent years has been undergoing a rapid growth all over the world. Prominent among the advancements of telecommunication is the evolution of modern converged network that provides the trio of data, voice and video network on a single network platform. The converged technology uses the internet as a medium to transmit data, voice and video packets using packet switching. This comes with numerous benefits by providing add-ons to both the service providers and users. The VoIP technology has been widely accepted and has received a boost in most western countries like the US and UK where users are now migrating from the legendry Public Switch Telephony Network (PSTN) to VoIP because of the numerous benefits it offers but unfortunately the business environment in Nigeria is yet to key into this promising technology. This study therefore focuses on introducing and implementing this technology in a converged network in Nigerian environment. It will also showcase VoIP’s numerous advantages and look at issues likely to be encountered during its implementation. It is hoped that it will help to serve as a tool in decision making process by converging the VoIP network with the already available data network.

− Computer network is something that cannot be separated with network topology, the number of computers much take a concerted on reliable connection and integrity that they can directly communicate with one each other, supported by the... more

− Computer network is something that cannot be separated with network topology, the number of computers much take a concerted on reliable connection and integrity that they can directly communicate with one each other, supported by the security level of reliable data, data security is an indispensable addition to the reliability of QoS (quality of service). It regulates the quality of the network in addition to the connection also the smoothness of the data, one of the technologies used today is a VOIP (Voice Over Internet Protocol), the technology can currently be implemented on homes and high rise buildings and office facilities , the technology is also very useful for replacing calls abroad were too expensive view, using VOIP charges can be pressed possible, while fatherly data security could use the technology VLAN virtual local area network, where the technology that the number of devices that are used can be minimized but with more optimal performance Intisari  Jaringan komputer adalah suatu hal yang tidak bisa dipisahkan dengan konfigurasi dan rancangan sebuah topologi, terutama jika komputer tersebut memiliki jumlah jaringan yang sangat banyak maka diperlukan sebuah rancangan jaringan yang saling terkoneksi dan terintegrasi, sebuah komunikasi yang handal didukung oleh sebuah keamanan data yang akan mempengaruhi tingkat layanan internet atau QOS (Quality Of Service). Salah satu teknologi yang dipakai adalah VoIP (Voice Over IP), teknologi tersebut bisa diimplementasikan dilingkungan rumah,pada kantor dengan posisi bangunan bertingkat dan berguna untuk mengganti panggilan ke luar negeri dengan menggunakan VOIP biaya dapat ditekan mungkin, sementara untuk keamanan data bisa VoIP bisa kombinasikan menggunakan teknologi VLAN jaringan lokal virtual, di mana dengan teknologi tersebut jumlah perangkat yang digunakan dapat diminimalisir namun dengan kinerja yang lebih optimal Kata Kunci  VOIP,VLAN, Local Area Network

This paper investigates the impact of different telephone channels, represented by impairments as introduced by modern telecommunication networks (e.g. speech coding, bandwidth limitation, packet loss, etc.), on the intelligibility of... more

This paper investigates the impact of different telephone channels, represented by impairments as introduced by modern telecommunication networks (e.g. speech coding, bandwidth limitation, packet loss, etc.), on the intelligibility of synthesized speech. Both subjective and objective assessments are used. Two different speech intelligibility prediction models, namely PESQ Intelligibility and POLQA Intelligibility, are evaluated by comparing the predictions with subjectively obtained intelligibility scores. The results show that all the investigated degradations seriously impact the intelligibility of the synthesized speech measured subjectively. Furthermore it is shown that PESQ Intelligibility provides too low correlations between predicted objective measurements and subjective scores for accurate prediction of speech intelligibility while POLQA Intelligibility is capable of providing good intelligibility predictions in the case that a closed response experimental set up is used.

Abstraksi Salah satu model alat telekomunikasi yang handal pada saat terjadi bencana adalah perangkat radio komunikasi. Perangkat radio dengan model Handy Talky, memiliki kemampuan jarak komunikasi yang terbatas. Dengan menggembangkannya... more

Abstraksi Salah satu model alat telekomunikasi yang handal pada saat terjadi bencana adalah perangkat radio komunikasi. Perangkat radio dengan model Handy Talky, memiliki kemampuan jarak komunikasi yang terbatas. Dengan menggembangkannya menjadi RoIP (Radio Over IP) maka sistem telekomunikasi radio tersebut di tumpangkan pada sistem VoIP agar sistem telekomunikasi radio menjadi lebih global dan mampu mengatasi masalah interoperabilitas dalam masalah telekomunikasi secara umum dan sistem telekomunikasi tanggap bencana. Penelitian ini meneliti tingkat kehandalan dari RoIP (Radio Over IP) yang terimplementasi pada sistem komunikasi tanggap bencana. Pengujian meliputi sistem VOX/Switcher, Packet Loss dan Delay terhadap penggunaan CODEC dan jumlah pengguna serta kualitas internet mobile dari beragam provider yang mampu di gunakan untuk sistem RoIP. Kata kunci: RoIP, Radio Over IP, VOX, CODEC, Tanggap Bencana

This paper presents new evidence about user perception of VoIP quality that is inconsistent with the general understanding of three codecs know as G.729, G.711 and G.722. The focus of the study is aimed at VoIP quality evaluation by Thai... more

This paper presents new evidence about user perception of VoIP quality that is inconsistent with the general understanding of three codecs know as G.729, G.711 and G.722. The focus of the study is aimed at VoIP quality evaluation by Thai users that use the Thai language which is tonal. This study was conducted by using conversation-opinion tests. The results, called MOS-CQS, were then analyzed carefully. After the study and analysis, it has been found that the perception of subjects, who were Thai native speakers, to G.729, G.711 and G.722 is not significantly different.

Ce mémoire a été rédigé à la suite d'un stage académique effectué du 01 Juillet 2017 au 30 Septembre 2017 au Ministère de la Femme, de la Solidarité Nationale et de la Famille. Ce stage effectué à la fin de notre formation en cycle de... more

Ce mémoire a été rédigé à la suite d'un stage académique effectué du 01 Juillet 2017 au 30 Septembre 2017 au Ministère de la Femme, de la Solidarité Nationale et de la Famille. Ce stage effectué à la fin de notre formation en cycle de Licence d’Ingénierie des Systèmes et Réseaux à Sup’Management Burkina, nous a permis non seulement de nous imprégner des réalités du milieu professionnel qu'est l'entreprise mais aussi et surtout de faire l'adéquation entre la pratique et la théorie issue des enseignements reçus en matière de systèmes et réseaux.
La VOIP est une technologie qui s'impose progressivement dans tous les secteurs, elle consiste à faire transiter les communications téléphoniques par le réseau IP. Elle est aujourd'hui de plus en plus déployée au sein des grandes entreprises. Le développement de la VoIP est parti d'un simple constat : comment faire en sorte d'utiliser les potentialités du réseau IP afin de téléphoner moins cher (voire gratuitement) ? C'est dans le but de convergence sur les réseaux qu'est apparu le protocole SIP issu des grands opérateurs réseaux. IL est souple et évolutif.

Attacks on networks which implement VoIP could lead to the degradation of the IP PBX performance, the interception of conversations, the theft of important and confidential information, and the generation of large expenses in any... more

Attacks on networks which implement VoIP could lead to the degradation of the IP PBX performance, the interception of conversations, the theft of important and confidential information, and the generation of large expenses in any organization, if they do not have the correct security mechanisms. VoIP is based on existing layers and protocols and therefore inherits their security issues. In relation to signalization, different protocols have been proposed for VoIP. However, the Session Initiation Protocol (SIP) tends to be the favorite one because it is standardized by the IETF and has many features. Similarly to any other Internet protocol, SIP is susceptible to security threads, and can be involved in different kinds of attacks. In this paper, we propose three basic scenarios, representing common fundamental network architectures for VoIP, from which more complex systems can be built. We also establish a set of policies and guidelines focused on the aforementioned architectures, in order to mitigate security threads and provide more effective solutions for existing vulnerabilities in VoIP.

The inherent needs of organizations to improve and amplify their technological platform entail large expenses with the goal to enhance their performance. Hence, they have to contemplate mechanisms of optimization and the improvement of... more

The inherent needs of organizations to improve and amplify their technological platform entail large expenses with the goal to enhance their performance. Hence, they have to contemplate mechanisms of optimization and the improvement of their operational infrastructure. In this direction arises the need to guarantee the correct operation and non-degradation of the services provided by the platform during the periods with a significant load of work. This type of scenario is perfectly applicable to the field of VoIP technologies, where users generate elevated loads of work on critical points of the infrastructure, during the process of interaction with their peers. In this research work, we propose a solution for high availability, with the goal of maintaining the continuity of the operation of communication environments based on the SIP protocol in high load. We validate our proposal through numerous experiments. Also, we compare our solution with other classical VoIP scenarios and show the advantages of a high availability and fault tolerance architecture for organizations.

Abstrak Asymmetric Digital Subscriber Line (ADSL) merupakan teknologi yang sudah cukup lama digunakan. Namun, dalam memberikan pelayanan Voice Over Internet Protocol (VoIP) perlu dilakukan pengamatan yang lebih mendalam. Dalam penelitian... more

Abstrak Asymmetric Digital Subscriber Line (ADSL) merupakan teknologi yang sudah cukup lama digunakan. Namun, dalam memberikan pelayanan Voice Over Internet Protocol (VoIP) perlu dilakukan pengamatan yang lebih mendalam. Dalam penelitian ini diamati beberapa parameter Quality of Services (QoS) yaitu delay, jitter, packet loss, dan throughput untuk mengukur tingkat performansi teknologi ADSL dalam memberikan pelayanan VoIP. Dalam penelitian ini pengamatan dilakukan pada komunikasi point to point antara client 1 dan client 2 serta membandingkan QoS dari beberapa waktu yang berbeda yaitu pagi, siang, dan malam hari. Hasil pengamatan menunjukkan performansi ADSL dalam memberikan layanan cukup baik sesuai dengan standar ITU G.114 dimana waktu pagi hari memiliki tingkat QoS yang paling baik dibanding waktu-waktu lainnya.

Abstrak— Teknologi VoIP (Voice Over Internet Protocol) merupakan teknologi yang mampu melewatkan panggilan suara, video dan data dalam jaringan IP. Voice over Internet Protocol (VoIP) dalam teknologi komunikasi cukup signifikan sehingga... more

Abstrak— Teknologi VoIP (Voice Over Internet Protocol) merupakan teknologi yang mampu melewatkan panggilan suara, video dan data dalam jaringan IP. Voice over Internet Protocol (VoIP) dalam teknologi komunikasi cukup signifikan sehingga tidak terlepas dari kejahatan cybercrime, Teknologi VoIP dapat disalahgunakan untuk melakukan tindakan kejahatan jarak jauh sehingga diperlukan langkah-langkah investigasi jika terjadi masalah. Menemukan artefact pada Infrastruktur VoIP merupakan tantangan tersendiri. WireSharks salah satu tool yang digunakan dalam investigasi ini. Metode yang digunakan adalah DFIF yang terdiri tahapan adalah Collection, Examination, Analysis, dan Report and Documentation. Investigasi pada layanan VoIP dapat berhasil dilakukan dengan menemukan data digital evidence di layer 5. Tujuan Penelitian ini yaitu Mengetahui Karakteristik Data Digital berupa suara pada layanan Voice Over IP dan Menganalisis Data Digital berupa suara pada layanan Voice Over IP. Hasil dari penelitian ini barang bukti digital yang berupa percakapan yang dapat dipertanggungjawabkan dalam pengadilan..