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1.
While each IP domain can deploy its own strategy to manage network resources, multimedia traffic needs end-to-end QoS management to obtain an overall service level. The provision of end-to-end QoS over a heterogeneous environment implies the negotiation of a mutually acceptable SLA. This article presents the use of the COPS-SLS protocol as a generic protocol for automatic service-level negotiation and the integration of this protocol in an overall QoS management architecture to manage service levels over multiple domains deploying different QoS technologies.  相似文献   

2.
This article presents a survey of the protocols that have been proposed for facilitating dynamic service negotiation in the next-generation Internet. We begin by illustrating the terms service level agreement and service level specification defined by the IETF. We then discuss the working of the existing service negotiation protocols with respect to generic network architecture. Following that, we enumerate a list of characteristics desired in an ideal service negotiation protocol and draw a comparison between the various protocols based on this list. We conclude the article by discussing possible future research directions in this area.  相似文献   

3.
As an exercise in agent-based software engineering, this work proposes a holonic model for the domain of supply chain management. The supply chain system is a distributed infrastructure that enforces protocol rules and through which agents registered on a domain find each other, access the knowledge base, communicate (exchange messages), and negotiate with other agents, which are independent entities with specific goals and resources. It is considered that individual resources that belong to each agent are not sufficient to satisfy their goals; therefore, the agents must procure the needed resources from other agents present in the system through negotiation. Our approach is based on the holonic enterprise model with the Foundation for Intelligent Physical Agents (FIPA) Contract Net protocols applied within different levels of the supply chain holarchy. To accommodate differentiation of interests and provide an allocation of resources throughout the supply chain holarchy, we use nested protocols as interaction mechanisms among agents. Agents are interacting through a price system embedded into specific protocols. The negotiation on prices is made possible by the implementation of an XML rule-based system that is also flexible in terms of configuration and can provide portable data across networks.  相似文献   

4.
Nader Mbarek  Francine Krief 《电信纪事》2007,62(9-10):1079-1098
We propose a framework for service level negotiation within s elf-management systems. The negotiation process occurs between high-level autonomic managers to guarantee an end-to-end service level for specific application traffic flows. In the proposed framework, we provide autonomic systems with a new interaction opportunity thanks to the negotiation with their peers. To be in conformance with the concepts of self-aware management systems, the proposed negotiation protocol called SLNP is used in a Web Services environment.  相似文献   

5.
Polyrakis  A. Boutaba  R. 《IEEE network》2002,16(2):40-48
The growth of computer networks has revealed significant scalability and efficiency limitations to the traditional management techniques. Policy-based networking (PBN) has emerged as a promising paradigm for configuration management and service provisioning. The common open policy service (COPS) and its extension for policy provisioning (COPS-PR) are currently being developed as the protocols to implement PBN. COPS-PR has received significant attention and seems efficient for several management areas. However, the rigidity of its policy-enforcing mechanisms constrains the intelligence that can be pushed toward the managed devices. This work aims at relaxing this limitation by using meta-policies, rules that enforce the appropriate policies on the devices. Meta-policies are stored and processed by the devices, independent of their semantics, thus making the model more efficient, scalable, distributed, and robust. The additional functionality is implemented through a novel policy information base we have defined, the meta-policy PIB  相似文献   

6.
QoS control by means of COPS to support SIP-based applications   总被引:1,自引:0,他引:1  
Salsano  S. Veltri  L. 《IEEE network》2002,16(2):27-33
The COPS protocol has been designed to enable communication on the interface between the policy decision administrator and the policy enforcement devices in a policy-based networking environment. It can be recognized that on the same interface there is the need to transfer information related to the request of resource by QoS clients and for the allocation of resources by resource allocation servers (e.g., bandwidth broker) in a DiffServ network. Hence, it is sensible to add this resource allocation functionality in the COPS framework. In particular, there are at least two cases where it is sensible to use COPS. The first case is on the interface between an edge node and a resource control node for handling resource allocation in a network provider domain. The second case is on the interface between a customer (client of a QoS enabled network) and the network provider: here COPS can be used as a protocol to signal dynamic admission control requests. In this article we present the definition of a new COPS client type to support the above-mentioned functionality, then describe an application scenario where SIP-based IP telephony applications can use Diffserv-based QoS networks. Simple backward-compatible enhancements to SIP are needed to interact with COPS/Diffserv QoS. A testbed implementation of the proposed solutions is finally described  相似文献   

7.
The Internet is a set of interconnected domains in which different QoS technologies can be deployed. The dynamic provision of end-to-end QoS over heterogeneousip networks assumes the negotiation of mutually acceptablesla. This paper presents the concept of intra-, inter- and multiple-domain service level negotiation using thecops-sls protocol. The negotiation process gives different parties in the negotiation the ability to agree upon the service level that a data stream can obtain, along with the permissible pricing of the service.  相似文献   

8.
Security service level agreements (SSLAs) provide a systematic way for end users at home or in the office to guarantee sufficient security level when doing business or exchanging sensitive personal or organizational data with an online service. In this paper, we propose an SSLA negotiation protocol that implements non‐repudiation with cryptographic identities and digital signatures and includes features that make it resistant to denial of service attacks. The basic version of the protocol does not rely on the use of a trusted third party, and it can be used for all kinds of simple negotiations. For the negotiation about SSLAs, the protocol provides an option to use an external knowledge base that may help the user in the selection of suitable security measures. We have implemented a prototype of the system, which uses JSON Web Signature for the message exchange and made some performance tests with it. The results show that the computational effort required by the cryptographic operations of the negotiation protocol remains at a reasonable level. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

9.
Interworking of IP multimedia core networks between 3GPP and WLAN   总被引:1,自引:0,他引:1  
The 3GPP has specified the IP multimedia subsystem (IMS) for the provisioning of multimedia services in UMTS Release 5 and later. Interconnection at the service layer between 3GPP and LAN networks requires interworking between IMS and WLAN functionalities. Studying several interconnection scenarios and the main functionalities of IMS, this article analyzes how the interconnection of 3GPP and WLAN networks may be performed in order to support different levels of service interconnection. Special attention is paid to interconnection at the session negotiation level, using SIP (the base protocol of the IMS) to provide session negotiation with QoS and AAAC support.  相似文献   

10.
首先介绍IMS基本网络架构,接着重点指出IMS终端设备接入核心网及业务平台的接口及协议,并总结了终端设备常用的认证方式、能力协商模式、会话修改的不同消息以及信令协商和媒体通信时可能存在的问题等。本最后提出一种IMS终端协议一致性测试系统的设计方案,其中包括协议一致性测试系统的框图、基本要求及设计要点等,以期望达到多媒体终端设备在不同应用场景下良好互通的目标。  相似文献   

11.
Presents AGENDA (A GENeral testbed for Distributed AI Applications), a simulation tool developed for the simulation and design of applications involving interacting entities. This testbed consists of two different levels, the architecture level and the system development level. The architecture level describes a methodology for designing software agents by providing several important functionalities an agent should have. On the other hand, the system development level provides the basic knowledge representation formalism, general inference mechanisms, and a simulation tool-box supporting visualization and monitoring of agents. Following this, the applicability of AGENDA to the transportation domain is presented in detail. The main challenge of AGENDA in the context of this domain has been to provide different cooperation-scalable methods based on negotiation, leading to different scheduling mechanisms, and to experimentally evaluate these mechanisms. This evaluation shows that: (1) AGENDA is suitable for realistic application in the transportation domain; (2) the mechanisms used for vertical negotiation (between trucks considered as agents) and for horizontal negotiation (between companies considered as agents) are applicable for the real-world transportation domain applications. Finally, a complete study of the scalability of the simulation tool and the algorithms used for the negotiation is presented. This study, along with the evaluation of the different mechanisms, can help designers of transportation companies, particularly in the case of large companies  相似文献   

12.
分布式Web服务QoS注册中的高效负载均衡方法   总被引:1,自引:0,他引:1  
该文提出了一种分布式Web服务QoS注册系统的负载均衡方法。提出了节点负载状态划分的概念。根据负载状态采用不同的负载信息散布策略,极大地减少了网络消耗。提出了基于简单协商的负载均衡方法。负载均衡用数据复制的方式,主要特点是在进行实际负载均衡操作以前即与复制目标节点进行协商,提出合理的复制需求,然后根据对方提供的资源情况,发起复制。提高了负载均衡的效率,降低了复制的盲目性。该方法在分布式Web服务QoS注册原型系统中进行了实验,达到了较好的效果。  相似文献   

13.
The performance of the connection-less network service (CLNS) over a satellite link with features such as high propagation delay and a varying (often high) level of errors, can be improved using the connection oriented data link (CODL) service. However, although existing CODL protocols satisfy the requirements of a connection oriented network protocol (e.g. X.25), they are not optimal for the CLNS over satellite links. The interaction of link error recovery procedures with the error recovery procedures implemented by CLNS users, the unnecessary delay due to link protocol sequencing and recovery procedures, and the interaction between applications with different quality of service (QoS) requirements cause most CODL protocols to have a detrimental impact on the performance of the CLNS. This study presents a new link protocol, which improves the quality of the CLNS (e.g. IP), especially considering the enhancement of the performance of connection-oriented transport protocols (e.g. TCP). The performance improvement using the new link protocols is demonstrated by implementation in a satellite interworking unit.  相似文献   

14.
The Internet protocol (IP) was created as a connectionless network layer protocol that takes no attempt to distinguish between various application types. Hence, the integration of a wide range of telecommunication services over the Internet is the main reason behind the need for the provision of quality of service (QoS) guarantees to end users. In such multiservice networks, resources are managed based on service level agreements (SLA), acknowledging different types of traffic in terms of bandwidth requirements, delay and other QoS parameters. An SLA is the documented result of a negotiation between a customer and a service provider that defines service characteristics, responsibilities and priorities of every party. An SLA may include statements about tariffing and billing, service delivery, and compensations. This paper provides a short overview of some aspects of quality of service, and identifies main issues and problems of defining and managing an SLA, based on its current standardization stage.  相似文献   

15.
DiffServ-like domains bring new challenges to quality of service (QoS) multicast routing simply by shifting the focus from individual flows into classes of flows. Packets are marked at edge routers and receive differentiated treatment according to the class and not the flow that they belong to. DiffServ therefore became adverse to multicast, as packet replication inside the domain may require classification and remarking functions not present in core nodes. At the interdomain level, no doubt multicast QoS complexity is increased by the interleaving of DiffServ and non-Diffserv domains, making it more difficult to address QoS multicast in an end-to-end perspective. In today’s real interconnection world, classes of service have no meaning in certain links of a full interdomain path. While the problem is not new, as already pointed out, there are no real efforts to bring multicast back to a class-of-service domain without compromising its model of operation. In this article, we present an innovative multicast QoS routing strategy, clearly designed for the new class-of-service paradigm. The solution is based upon the construction of multiple trees, one per class of service available, while still allowing receivers to shift for source-specific trees in its own class of service. The strategy is presented in a full end-to-end perspective. Intradomain trees use differentiated routing paths thus helping traffic differentiation. Intradomain receivers are allowed to shift from shared trees into an adequate class-of-service source tree. At interdomain level, each class-of-service interdomain tree branch is accomplished by means of an improved path probing strategy enabling for QoS path establishment. This paper presents this new strategy, and associated protocols, for constructing several multicast and directed distribution trees, one per class of service, within each multicast group. This new strategy and associated protocols are then simulated using NS-2 platform. Simulation results are analyzed and compared with other multicast routing solutions, both at intra- and interdomain levels.  相似文献   

16.
The existing RFID (Radio Frequency Identification) security protocol lacks the key establishment mechanism, assuming only that both parties of the authentication protocol have shared their respective session keys. However, key establishment is an integral part of the RFID security system. This article first introduces the elliptic curve related mathematical theory foundation. Then we establish the key negotiation mechanism, and analyze the correctness and rationality of the negotiation mechanism. Finally, we design the authentication protocol based on elliptic curve in mobile RFID system, analyze the protocol authentication process, and compare the security and performance with other protocols, which shows that the authentication protocol has more efficient performance and the ability to resist all kinds of attacks.  相似文献   

17.
葛维进  胡晓惠 《通信学报》2012,33(12):85-92
基于身份加密体系的隐藏证书原始模型存在无法实现一对多的信息传输、对身份信息不具备容错功能且密文容易被共谋破解等缺点。提出的基于属性加密的隐藏证书扩展模型通过引入属性集合证书技术、基于加解密精度阈值等特性,解决了上述三个问题。在分析国内外相关研究进展的基础上,对扩展模型在体系架构、系统构造、双方信任协商协议、多方信任协商协议以及扩展模型解决复杂逻辑访问策略的方法等进行了详细的阐述,并对扩展模型的安全性进行了分析。通过一个典型的应用场景,对比分析了新旧隐藏证书技术在性能和安全性上的区别,阐明了扩展模型的优点。  相似文献   

18.
This paper proposes a new dynamic bandwidth allocation system for Ethernet Passive Optical Networks (EPONs), subject to requirements of fairness, efficiency, and cost. An Optical Line Terminal (OLT)-centric bandwidth allocation model is proposed which employs a credit pooling technique combined with a weighted-share policy to partition the upstream bandwidth among different classes of service, and to prevent Optical Network Units (ONUs) from monopolizing the bandwidth. The OLT-centric model allows global optimization of network resources, a characteristic which is not found in many earlier proposals. Supported by the new bandwidth allocation, the paper proposes a joint-ONU interval-based packet scheduling algorithm, referred to herein as COPS (Class-of-service Oriented Packet Scheduling), that meets the requirements set out above. We compare COPS with another well-known scheduling algorithm which employed a standard priority-based bandwidth sharing. We show that COPS is superior in terms of network utilization and maximum packet delay, with the consequence of an increase in average packet delay for the premium traffic. This drawback is overcome by combining COPS with a rate-based optimization scheme.  相似文献   

19.
Multi‐Protocol Label Switching (MPLS) is deployed in the Internet backbone to support service differentiation and traffic engineering. In recent years, there has been interest in extending the MPLS capability to wireless access networks for mobility management support. In this paper, we present analysis of Micro Mobile MPLS, a new micro‐mobility management scheme which integrates the Mobile IP and MPLS protocols by using two‐level hierarchy architecture. Our proposal supports two protocol variants. First, the fast handoff process, which anticipates the LSP procedure set‐up with neighboring locations where a mobile node (MN) may move to, is provided to reduce service disruption. Second, a new mechanism based on the forwarding chain concept is proposed to track efficiently the host mobility within a domain. This concept can significantly reduce registration update costs and provide low handoff latency. Analytical models are developed and simulations are conducted to justify the benefits of our proposed mechanisms. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

20.
Existing services require assurable end-to-end quality of service, security and reliability constraints. Therefore, the networks involved in the transport of the data must cooperate to satisfy those constraints. In a next generation Internet, each of those networks may be managed by different entities. Furthermore, their policies and service level agreements (SLAs) will differ, as well as the autonomic management systems controlling them. In this context, we in the Autonomic Internet (AutoI) consortium propose the Orchestration Plane (OP), which promotes the interaction among different Autonomic Management Systems (AMSs). The OP mediates the communication and negotiation among AMSs, ensuring that their SLAs and policies meet the requirements needed for the provisioning of the services. It also simplifies the federation of domains and the distribution of new services in virtualised network environments.  相似文献   

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