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.
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,...
The goal of this work is to characterize scientific data transfers and to determine the suitability of dynamic virtual circuit service for these transfers instead of the currently used IP-routed service. Specifically, logs collected by servers executing a commonly used scientific data transfer application, GridFTP, are obtained from three US super-computing/scientific research centers, NERSC, SLAC,...
Most user terminals or Internet hosts are equipped with two or more interfaces that can simultaneously be attached to different access networks. These multihomed hosts can offer ubiquitous and cost-effective connectivity, while improving resiliency and bandwidth. Each interface would get an address (or locator) from the edge network to which it attaches. Thus the multihomed host has multiple locators...
A drastic increase in traffic of mobile broadband is seen in the past few years, which is further accelerated by the increased usage of smart phones and its applications. The availability of good smart phones and better data connectivity are encouraging mobile users to use video services. This huge increase in usage will pose a lot of challenges to the wireless networks. The existing wireless networks...
Multi-homing is a new feature of SCTP not existed in UDP or TCP. It allows multiple IP addresses to be attached to a single connection to improve stability of data transfer. It significantly enhances reliability and redundancy of transport layer in several levels - from multiple physical network interface cards to complete different logical end-to-end paths. Recently, SCTP protocol was officially...
The current wireless network landscape comprises a plethora of technologies including WLAN, WiMAX and 3G, and not much speaks for a radical change of the state of affairs in the near future. In light of this, it becomes pivotal to facilitate vertical handover between different types of wireless networks. Although, a large number of vertical handover schemes have been proposed in the past several years,...
Even though core or backbone routers may have not vulnerability issues for TTL expiry DDoS attack, routers which have only a single processor for packet forwarding and control used in the small network may vulnerable for an TTL expiry DDoS attack. The reason is that forwarding and control functions are not completely separated so the packet dropping due to TTL expiration affects to packet forwarding...
Many protocols and communication standard appear in the Substation Automation System (SAS) world. Advanced communication standards a low the exchange of peer to peer information between primary devices in order to accomplish distributed automation application inside SAS. Evaluating the conformity of primary devices towards security and SAS architectures towards required specifications is a non trivial...
The IPv6 protocol is the next-generation IP protocol that addresses many of the shortcomings that exist in the IPv4 protocol. Some of the enhancements include increased address space, mandatory security and provisioning of stateless auto-configuration, a technique through which a new node forms its own address without the assistance of centralized host configuration servers operating in the network...
In this paper, a delay tolerant approach for traffic management in LTE over satellite link is presented. Due to the long propagation delays and frequent disruptions, mobile satellite communications pose many challenges, especially to the transport layer when the TCP protocol is used. We design and evaluate the performance of a transport protocol solution based on the DTN architecture in the satellite-LTE...
Explicit Congestion Notification (ECN) is an addition to the Internet Protocol and the Transmission Control Protocol (TCP) which aims in improving the performance of TCP and other transport layer protocols. ECN is only meaningful when combined with bottleneck links that use Active Queue Management (AQM). Random Early Detection (RED) and other AQM mechanisms have been subject of criticism regarding...
In the recent years, with the gradually deep researches of the Internet of Things (IOT), the DNS based on identity and IP (IIEDNS) also attracts people's attention. The major task of this paper is to solve the problems of security-authentication. Since the traditional identity-authentication technologies couldn't satisfy the needs to the identity and IP authentication of the IIEDNS, we propose an...
Infrastructure networks like Internet have some coverage gaps (e.g. rural areas) where no service connectivity is provided. Cellular networks could be used in alternative but they usually associate their services with a usage cost. Nowadays, the growing number of mobile devices equipped with a wireless interface and the end-user trend to shift toward wireless technology has opened new possibilities...
Active Queue Management (AQM) and Explicit Congestion Notification (ECN) are two methods that attempt to alleviate the problems of FIFO queues and of packet drops for congestion indication respectively. Random Early Detection (RED) is the most popular AQM method. The Domain Naming System (DNS) protocol is a core Internet protocol with very high impact on user experience and overall network functionality...
Recent collapses of SIP servers in the real carrier networks indicate that the built-in SIP overload control mechanism cannot mitigate overload effectively. In this paper, we investigate the root cause of SIP server crash by studying the impact of the retransmission on the queuing delay of the overloaded server. The transient overload may introduce the excessive queuing delay, thus triggering unnecessary...
This paper presents the results of the performance evaluation concerning 3G/3GPP IP Multimedia Subsystem (IMS) applications deployed in a wireless multi-hop network controlled by the Delay-Aware Network Utility Maximization System (DANUMS). The main purpose of the DANUM system is simultaneous service of files and multimedia streams, i.e., types of traffic of different delay requirements. DANUMS combines...
IP reconfiguration using DHCP is the usual approach followed by mobile nodes (MNs) when they roam from one network to another one. However, DHCP is too slow for cooping with fast handover requirements. This article describes a cross-layer approach for accelerating DHCP-based IP reconfigurations in a mobility scenario across 802.11 access points (APs). DHCP transactions are initiated by neighboring...
The paper is about mobile Stream Control Transmission Protocol (mSCTP) and the problems related to simultaneous mobility. Simultaneous mobility is when the both endpoints of a communication session are mobile and they move at about the same time. mSCTP works well in the case of non-simultaneous mobility where the SCTP association is established between a mobile endpoint and a stationary one. In the...
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...
With the advancement of Internet technologies and the widespread use of mobile devices, the number of users in conferencing services is increasing quickly. A P2PSIP conferencing system and an IP Multimedia Subsystem (IMS) conferencing system have been designed to provide conferencing services. The IMS conferencing system was developed to adapt to a server-based centralized system, while the P2P network,...
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.