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The IP Multimedia Subsystem (IMS) seems to be the technology that will prevail in Next Generation Networks (NGN s), since the interworking environment and the service flexibility that this technology offers to the currently deployed wireless broadband technologies makes it appealing to users, service developers and network operators. In this paper a heterogeneous network model based on the IMS that...
This paper investigates and compares the performance of the popular VoIP codecs G.711, G.723.1 and G.729A over an IP network based on SIP architecture, using RTP as a transport protocol. This is based on different simulations in order to evaluate the performance of each codec and to find the optimal codec. For this objective this paper analyzes Quality of service (QoS) parameters, principally delay,...
VoIP is replacing traditional telephony system over PSTN as a more affordable communication tool on account of convergence of networks. Meanwhile, security issue brings more attention and becomes more important. SIP is based on text message. This makes the protocol easy to implement but also creates opportunity for hackers to steal or modify the messages. There exist a various approaches to secure...
Security is an important concern in Voice over IP (VoIP) applications. An approach to securing the signaling, such as the Session Initiation Protocol (SIP) and Location to Service Translation (LoST) messages, is to use Transport Layer Security (TLS). Several studies have measured the impact of using TLS on SIP. However, there have not been any tests on the impact of TLS or Internet Protocol Security...
As the Session Initiation Protocol (SIP) becomes more and more the core of the communication networks convergence, there is urgent need to manage the critical problem of SIP service availability under extreme overload. This paper proposes a novel solution to control SIP overload. We demonstrate the efficiency of the approach compared with a well known SIP overload control algorithm. The solution builds...
Over the last years the IP Multimedia Subsystem (IMS) has continuously gained in importance as the next generation communication network. The Session Initiation Protocol (SIP) was chosen the signaling protocol for session establishment and control in IMS. Losses caused by network or server overload would cause retransmissions and delays in the session establishment and would hence reduce the perceived...
“Push-to-talk over Cellular” (PoC) which is wireless technology and is used on mobile telecom network can enable cell phones capability of one-to-many communications, as the walkie-talkie. PoC is a new potential communication service using cellular network without the defect of walkie-talkie limited communication distance. In this paper, the performance of today's PoC is evaluated,...
With the proliferation of the Internet, voice over IP and multimedia communication become more and more important. One of the protocol that facilitated this development is Session Initiation Protocol (SIP). SIP is a signaling protocol which manages the session establishment and termination. It can be based on UDP or TCP at the transport layer. In this paper, the strengths and weaknesses of SIP over...
IMS is the new approach adopted by 3GPP towards networks convergence. It was designed to be access independent and ubiquitous. IMS already provides personal mobility for nomadic users, but still needs to deal with service continuity within non 3GPP networks. In this paper we propose a novel hybrid mobility management scheme, based on tight cooperation between fast handovers for mobile IPv6 (FMIPv6)...
The rapid advancement of mobile communication technologies recently has led to the advent of mobile IPTV service. For a variety of multimedia services, a process of session setup using SIP (session initiation protocol) is required. However, high frame error rate (FER) of typical wireless network causes failure and delay in session setup. In this paper we propose a new scheme minimizing the session...
As a main signaling protocol for multimedia sessions in the Internet, SIP (Session Initiation Protocol) introduces a retransmission mechanism to maintain the reliability for its realtime transmission. However, retransmission will make the server overload worse. Recent collapse of SIP servers due to emergencyinduced call volume indicates that the built-in SIP overload control mechanism cannot prevent...
In recent years the Department of Defense has aggressively invested in development of an Internet Protocol (IP) based network that interconnects mobile air platforms and ultimately will also connect to the Global Information Grid (GIG) as part of its Net-Centric Warfare initiatives. One of the major visions for the IP based networks is to support interoperable voice communication amongst heterogeneous...
SIP (Session Initiation Protocol) has been widely adopted as a signaling protocol to establish, modify and terminate multimedia sessions between end-users in the Internet. SIP introduces a retransmission mechanism to ensure the reliability of its real-time message delivery. However, retransmission makes server overload worse, as indicated by the recent server crashes in the real carrier networks....
Technology of multimedia communications on network is rapidly developing today. SIP (Session Initiation Protocol), which plays an important role in 3G standards, is well applied in multimedia conferencing systems. Traditionally, most SIP-based conferencing systems have been limited in scalability due to their tightly coupled centralized structures. However, distributed conferencing based on SIP is...
The Application continuity in IMS requires Mobility Management to ensure Session having Seamless handover and small delay. As a Session Control Protocol of IMS, SIP introduces big delay and real-time handover problems. In this letter, we proposed a combination scheme of SIP and mSCTP to solve the problem of Application continuity in IMS. We presented a novel approach for the problem of Compatibility...
Simply, internet telephony is telephone network using internet as its communication media. The specific character of a telephone is its ability to make connection to the destination telephone number. So that the right term is actually internet telephony than VoIP which is more aimed to voice communication via internet, so there is no emphasizing on the ability of call directed to the destination phone...
With the rapid development of the Internet, new technologies and applications are emerging. One of the important applications is voice over IP. Satellites are playing an important role to provide VoIP services with their global coverage and on-board processing ability over IP networks. Satellite network environment, generally characterized by large delay and erroneous link, is considered to be unfriendly...
This paper in accordance with the authors' previous work, investigates the effect of adding extra servers in Session Initiation Protocol (SIP) signaling network on session setup in the Ip Multimedia Subsystem (IMS). The delay analysis is explored by describing the SIP signaling traffic with M/M/r notation. SIP servers overload problem is addressed and the effect of adding servers will be investigated...
Peer-to-peer mechanisms are considered as one of the key innovative and user-friendly solutions for real-time Internet communication services. Eliminating server-based architecture, reducing or eliminating configuration effort, and allowing end-user devices to bring resources into the network, will reshape the network as we currently know it. This presents substantial opportunities for networks and...
Session initiation protocol (SIP) has potential to be selected as a control plane signaling protocol for delivering real-time multimedia applications in military networks. It is necessary to study behaviors of SIP and SIP-based real-time applications as well as to understand their limitations in a tactical network environment. The goals of this study are to assess SIP signaling protocol performance...
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