The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
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...
End-to-end QoS is a challenge for future Internet. A per flow resource reservation can be carried out among heterogeneous domains on the communication path using signaling protocols. When one or both communicating terminals are mobile there is additional complexity. Signaling delays and resource lacking on future paths can dramatically impact user experience. In this paper, a rational future path...
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...
A new hybrid signaling scheme is proposed in this work, that combines a two-way with an one-way reservation protocol. The key idea is to synchronize the assembly process with the reservation and hard reserve part of the end-to-end path in two way mode, for a duration equal to the burst assembly time. In this way, upon the arrival of the first packet in the assembly queue, the two-way reservation part...
This paper focuses on reducing the Network Address Translator (NAT) traversal-related components of the session establishment delay in peer-to-peer Session Initiation Protocol (P2PSIP) overlays. To reduce the delay, we propose to group the management of different connections so that the (time-consuming) NAT traversal procedures performed for one connection can be reused when establishing other connections...
The IP Multimedia Subsystem (IMS) has been considered to be exclusive to big players of the telecommunication world. Session Initiation Protocol (SIP) has been standardized by IETF and solutions based on it have been in the market at least for a decade. It is also an essential part of the IMS, as it is the control protocol of IMS. Recent development of the Linux platform and the Open source IMS system...
The presence service provides event-based notifications of the status of contacts. Currently duplicate notifications must be sent directly to a set of watchers in unicast messages, putting unneeded strain on outgoing network links of the source node. In this article, we propose an extension to the Session Initiation Protocol (SIP) to distribute notifications through a tree of watchers using network...
Peer-to-Peer Session Initiation Protocol (P2PSIP) is a distributed communication system being standardized in the Internet Engineering Task Force (IETF). Since it uses the peer-to-peer paradigm, P2PSIP faces the problems created by Network Address Translators (NATs); even peers located behind NATs need to be able to not only initiate connections to other peers but also accept connections initiated...
Retransmission mechanism helps SIP maintain its reliability, but it can also make an overload worse. Recent server collapses due to emergency-induced call volume in carrier networks indicate that the built-in overload control mechanism cannot handle overload conditions effectively. Since the retransmissions caused by the overload are redundant, we suggest mitigating the overload by controlling redundant...
“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,...
The performance of SIP servers is largely degraded during overload conditions due to the built in message re-transmission mechanism of SIP. In this paper we propose a distributed and end-to-end adaptive window based overload control algorithm, by which upstream SIP servers control the amount of calls that are forwarded to a downstream SIP server in an attempt to prevent it from being overloaded. Our...
For accessing various resources via mobile device anytime anywhere, the heterogeneous access technologies between wired and wireless networks have been developed and integrated actively. However, real-time services, e.g., Voice over IP (VoIP) and video streaming suffer from long delay, and non-real-time connections, e.g., TCP connections, cause low transmission throughput while occurring timeout and...
With the increasing use of session initiation protocol (SIP) in large deployments and the fact that numerous conventional communication networks have been spread, it is profitably to build a next generation network (NGN) linking circuit and packet-switched networks. This paper is concerned with the quality-of-service (QoS) parameters estimation problem in NGN. We have proposed a mathematical model...
SCTP faces three performance problems in hard handover scenarios: high network handover delay, high transport handover delay and throughput under-utilization. Existing solutions assume the mobile extension of SCTP (m-SCTP) as a unique way to handle handovers and rely on terminal mechanisms. Nevertheless, they are not efficient as they lack the necessary information to perform on-time and fine SCTP...
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...
The network mobility (NEMO) basic support protocol is an extension of mobile IP that enables an entire network to maintain the Internet connection when it changes its attachment point to the Internet. However, it gives rise to high overhead, loss packet and long delay on the network link when a network as a unity moves frequently. These problems should seriously affect the communications, real time...
The Transmission Control Protocol (TCP) is a transport protocol which delivers packets strictly in order. For signaling protocols which send multiple independent requests within one single TCP session, the loss of a TCP packet may therefore lead to increased delay for later signaling requests. This phenomenon is known as Head-of-Line Blocking (HoLB) and for instance has led to the standardization...
It needs to consider the establishment and release of IP telephony signaling-SIP or H.323 while analyzing VoIP network performance with OPNET, involving complex protocol configuration such as MGCP. What's more, the simulation efficiency will be greatly reduced in large-scale network. This paper presented an new idea to study the performance of VoIP network, it used the built-in hybrid simulation mechanism...
Proxy Mobile IPv6 has been developed as a network-based mobility management protocol. This new protocol enables a mobile node to change its point of attachment without its own mobility signaling. That is, network entities provide the mobility service for the mobile node. In this paper, we introduce a new handover process designed for improving handover performance in terms of handover latency. The...
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)...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.