Search results for "Protocol"
showing 10 items of 1808 documents
Improvement of a Service Level Negotiation Protocol using Formal Verification
2013
International audience; The goal of the pervasive connectivity is to enable mobile users to be permanently connected to the Internet. Mobile users are often connected to wireless networks and consuming services that require quality of service guarantees. Accessing services using wireless technologies may make the service delivery vulnerable to security attacks because of the open medium of these technologies. In this context, we need to guarantee both quality of service and security for mobile users communications. In this paper, we present a protocol for service level negotiation which covers both quality of service and security and assigns a profile to each user in order to optimize and a…
Fuzzy-neural Web switch supporting differentiated service
2006
New designs of the Web switches must incorporate a client-and-server-aware adaptive dispatching algorithm to be able to optimize multiple static and dynamic services providing quality of service and service differentiation. This paper presents such an algorithm called FNRD (Fuzzy-Neural Request Distribution) which operates at layer-7 of the OSI protocol stack. This algorithm assigns each incoming request to the server with the least expected response time estimated using the fuzzy approach. FNRD has ability for learning and adaptation by means of a neural network feedback loop. We demonstrate through the simulations that our dispatching policy is more effective than state-of-the-art layer-7…
Inter-provider AAA and Billing of VoIP Users with Token-based Method
2007
With the increasing popularity of wireless LAN technology, providers of real-time voice over IP (VoIP) services, known as voice service providers (VSP), are asking for roaming solutions and AAA (Authentication, Authorization and Accounting) methods that allow users to use their services from any available public Internet access network. In this paper we propose an AAA and billing architecture that allows users of VSPs to have access to the Internet from wired and wireless access networks provided by both traditional carriers, such as 3G providers, and wireless local access network (WLAN) providers. We propose a token-based AAA method that allows users of VoIP services to have their VSPs as …
Secure interworking with P2PSIP and IMS
2010
In this paper, we propose a secure system model for interconnection between P2PSIP and IMS domains. The interworking solution is based on P2P-IMS GateWay (PIGW), which acts as a normal peer in P2PSIP network and a 3rd party IMS Application Server (AS) in IMS network. The security is achieved by implementing Chord Secure Proxy (CSP) and enhanced with subjective logic based trust model. We also implement this system model and analyze it in several aspects: number of hops and delay, trust improvement and protection against malicious or compromised intermediate peers. We conclude that the proposed architecture is feasible and improves security. As far as we know our research is the first study …
Trust enhancement of P2PSIP communication systems
2011
Today, peer-to-peer (P2P) session initiation protocol (SIP)-based communication systems have attracted much attention from both academia and industry. The decentralised nature of P2P might provide the distributed P2P communication system without help of the traditional SIP server. However, it comes to the cost of reduced trustworthiness and may cause security problems, e.g., privacy leaks, unpredictable availability, etc. In this paper, we investigate P2PSIP security issues and propose a subjective logic-based trust model that offers trust-based security services during P2PSIP session establishment. The main issues considered in this model include opinion calculation, opinion maintenance, d…
Transport service for session initiation protocol in SIP-T scenarios
2005
The traditional telephone service has undergone deep changes in the years concerning the techniques of commutation and signaling. Today, public switched telecom networks (PSTNs) and private integrated services networks (PINSs) are strongly directed to adopt IP-based backbone. If it is possible to transfer the voice on packet switching network, in such reliable way, using voice over IP (VoIP) techniques, there is not still a valid alternative to the signaling systems, reliable and unfailing, like signaling system n.7 (SST). Session initiation protocol (SIP) seems to be the best candidate. SIP is an application layer signaling protocol and the problem remains still opened for what it concerns…
Analysis and Simulation of the Signaling Protocols for the DiffServ Framework
2006
This paper considers signaling protocols for the DiffServ QoS framework. Originally, DiffServ had no standardized signaling solution, which resulted in the static configuration for the DiffServ domain. However, the dynamic allocation of resources within the domain allows to ensure the per-flow QoS guarantees and achieve better performance. At the moment, several signaling solutions for DiffServ framework are available. Thus, it is crucial to analyse these solutions and interconnections between them. In particular, the RSVP, aggregated RSVP, GIST, COPS, and SIP protocols will be considered. The simulation comprises several scenarios that present that the dynamic allocation of resource within…
Microspore embryogenesis in almond (Prunus dulcis Mill.)
2018
This chapter describes a protocol to regenerate microspore derived embryo via microspore embryogenesis through in vitro almond anthers culture.
Variazione degli stock di carbonio del suolo in seguito ai processi di abbandono dei coltivi: il caso studio dell’isola di Pantelleria (TP)
2007
The recent abandonment of marginal agricultural areas in the Mediterranean has caused an increase of the surface occupied by pre-forest and forest formations. In order to study the carbon accumulation processes on Pantelleria Island was selected a North-facing area. This area includes 5 stages of succession (sds) that compose a chronosequence (from 0 to 30 years) to understand soil C accumulation processes after abandonment. These are abandoned vineyards or caperbushes, not disturbed (grazing, fire) since agricultural abandonment, and they are situated in thermomediterranean belt and on the same parent material and consequently considered in the same ecological conditions. Samples at 1 cm, …
Estimating carbon credits variations supplied from agricultural and forest soils of Italy between 1979 and 2008.
2011
Soils contain approximately three times the world amount of organic carbon in vegetation and approximately the double of that present in the atmosphere. However, soil organic carbon (SOC) has been found lowering in many areas, while atmospheric CO2 was on increase. It is well known that there is a marked inter-dependence between SOC and climate, nevertheless, recent researches have demonstrated that changes of land use and management can cause gains or losses of SOC greater than climatic changes. Italy, which has joined the Kyoto Protocol, has decided to consider only forest management within the additional activities contemplated for the count of carbon credits, and to launch a monitoring …