Comparative study of protocols for dynamic service negotiation in the next-generation Internet

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.     

The AutoI approach for the orchestration of autonomic networks

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.     

COPS-SLS: a service level negotiation protocol for the Internet

The deployment of QoS over the Internet may achieve protocols for the negotiation of service levels, as well as mechanisms for the end-to-end realization of service level agreements. Such general-purpose protocols include Common Open Policy Service (COPS) for policy specification within a domain. This article proposes an extension of the COPS protocol for intra- and interdomain service level negotiation. The proposed protocol is known as COPS-SLS. This allows the configuration of domain policies regarding service levels, and the automatic negotiation of service levels within the domain policies     

A CORBA-based quality of service management framework fordistributed multimedia services and applications

For distributed multimedia services, it is essential that quality of service be guaranteed system-wide, including end systems, communication systems, and networks. Although many researchers have addressed issues of QoS management, little attention has so far been paid to the QoS management services in distributed multimedia services and applications. To address this deficiency, we have designed a layered model for end-to-end QoS management called the QoS management framework. Our framework, which is CORBA-based, includes a generic QoS MIB for the QoS parameterization of various multimedia services and the services needed to perform various QoS functions. A key component of this framework is the QoS management service object (QMSO), which orchestrates resources at endpoints, coordinating resource management across layer boundaries. Services such as translation, monitoring, admission, and negotiation are provided by the QMSO. To validate this concept, we have developed a QoS management system for managing and controlling the QoS of a distributed multimedia system called MAESTRO. The QoS management system has been implemented through CORBA objects and provides an interface to multimedia applications, which can be dynamic negotiation and renegotiation of QoS by users. Some performance results in QoS negotiation and renegotiation are also presented     

A Real-Time Service-Oriented Architecture for Industrial Automation

Industrial automation platforms are experiencing a paradigm shift. New technologies are making their way in the area, including embedded real-time systems, standard local area networks like Ethernet, Wi-Fi and ZigBee, IP-based communication protocols, standard Service Oriented Architectures (SOAs) and Web Services. An automation system will be composed of flexible autonomous components with Plug & Play functionality, self configuration and diagnostics, and autonomic local control that communicate through standard networking technologies. However, the introduction of these new technologies raises important problems that need to be properly solved, one of these being the need to support real-time and quality-of-service (QoS) for real-time applications. This paper describes a SOA enhanced with real-time capabilities for Industrial Automation. The proposed architecture allows for negotiation of the QoS requested by clients from web services, and provides temporal encapsulation of individual activities. This way, it is possible to perform an a priori analysis of the temporal behavior of each service, and to avoid unwanted interference among them. After describing the architecture, experimental results gathered on a real implementation of the framework (which leverages a soft real-time scheduler for the Linux kernel) are presented, showing the effectiveness of the proposed solution. The experiments were performed on simple case studies designed in the context of industrial automation applications.      

Accord: a programming framework for autonomic applications

The emergence of pervasive wide-area distributed computing environments, such as pervasive information systems and computational grids, has enabled new generations of applications that are based on seamless access, aggregation, and interaction. However, the inherent complexity, heterogeneity, and dynamism of these systems require a change in how the applications are developed and managed. In this paper, we present a programming framework that extends existing programming models/frameworks to support the development of autonomic self-managing applications. The framework enables the development of autonomic elements and the formulation of autonomic applications as the dynamic composition of autonomic elements. The operation of the proposed framework is illustrated using a forest fire management application.     

基于信任协商的开放系统授权服务模型的设计

提出了一种第三方的授权服务模型,对现存的信任协商系统起到支撑作用.模型作为一个授权代理,在实体使用信任协商确定一个适当的资源访问策略后,可以在一个开放的系统中发布访问资源的令牌.模型的体系结构设计允许集成新的信任应用程序,也可以间接集成现存传统的应用程序.讨论模型、模型使用的通信协议的设计和实现,以及它的性能.     

Pricing network resources for adaptive applications

The Differentiated Services framework (DiffServ) has been proposed to provide multiple Quality of Service (QoS) classes over IP networks. A network supporting multiple classes of service also requires a differentiated pricing structure. In this work, we propose a pricing algorithm in a DiffServ environment based on the cost of providing different levels of services, and on long-term average user resource demand of a service class. We integrate the proposed service-dependent pricing scheme with a dynamic pricing and service negotiation environment by considering a dynamic and congestion-sensitive pricing component. Pricing network services dynamically based on the level of service, usage, and congestion allows a more competitive price to be offered, allows the network to be used more efficiently, and provides a natural and equitable incentive for applications to adapt their service requests according to network conditions. We also develop the demand behavior of adaptive users based on a physically reasonable user utility function. Simulation results show that a congestion-sensitive pricing policy coupled with user rate adaptation is able to control congestion and allows a service class to meet its performance assurances under large or bursty offered loads, even without explicit admission control. Users are able to maintain a stable expenditure, and allowing users to migrate between service classes in response to price increases further stabilizes the individual service prices. When admission control is enforced, congestion-sensitive pricing still provides an advantage in terms of a much lower connection blocking rate at high loads.     

Service level negotiation andcops-sls protocol

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.     

A non‐repudiable negotiation protocol for security service level agreements

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.     

Distributed Busacker–Gowen algorithm for end-to-end QoS pipe negotiation in X-domain networks

Multimedia services and other critical multisite services (e.g., VPN) are becoming mainstream, and they require a guaranteed quality of service (QoS). Services need to be established across several autonomous systems (ASes), often to connect end-users. Thus, provisioning and control of end-to-end QoS requirements arise as one of the main challenges in inter-AS management. The contractual approach, consisting in using service-level agreements (SLAs) defined by each crossed AS, allows to negotiate contract chains that satisfy end-to-end requirements. However, establishing such chains by on-demand negotiations does not scale up for large numbers of requests. Hence, we propose a negotiation process to occur before users’ requests to establish service are received. The proposed negotiation process results in the selection of aggregated contract chains, called pipes, and a distribution between them. Such a distribution would indicate, for each chain of a pipe, the connection flow it may accept. In this paper, we address the pipe negotiation problem as a network flow problem. We also propose a distributed adaptation of an algorithm for network flow problems.     

An Architecture for Service Quality Management Using Cooperative Communications

The rapid enhancement and explosive expansion of mobile communication systems will lead to an increased demand for multimedia services. Various multimedia contents will be available due to the proliferation of IPTV, video on demand, user-generated content, and content-centric networking. Therefore, multimedia service quality is becoming a critical issue. The static allocation of network resources may not be sufficient to guarantee the required service quality of multimedia in wireless networks. For ensuring the service quality, it is important to manage the resources considering the overall performance of the network and the end system. In particular, a certain level of service quality should be maintained regardless of the network situation. To achieve this objective, we first propose an architecture for service quality management and then present a detailed framework and mechanisms to maintain the desired service quality using the cooperation between communication entities in wireless networks. Simulation results are also presented to show that the proposed framework works well in wireless networks.     

具有自律特征的网络故障管理框架

自律计算是IT研究的一个热点，它旨在设计出一种具有自我配置、自我优化、自我恢复和自我保护的计算机系统，使系统能够根据管理员给定的高层次目标进行自我管理。文章根据基本的控制理论．结合IBM提出的自律计算模型，将基于反馈的反应式控制和基于前馈的预测式控制相结合，运用于网络故障管理系统中，提出了一个具有自律特征的网络故障管理框架。最后，根据该故障管理系统的实现经验，分析了框架实现中的关键技术。     

Provisioning services on digital switching systems

The overall service provisioning process is functionally decomposed into three phases. The first is service negotiation, in which the customer's request is translated into machine-readable form (as a service order). The service order is the input to the second phase, assignment. If network resources are needed to satisfy the service request, the assignment process selects then from its inventory. The third phase is service activation. Attention is focused on the assignment phase, but emerging relationships among the three phases are also covered. The discussion begins with progress to date. Capabilities that have recently become available in Bellcore's operations systems using the flexible entity approach, are described. Issues and problems that arise as the switched network evolves to a greater degree of intelligence are considered, covering provisioning for ISDN, load balancing, service negotiation and assignment, customers doing their own provisioning, and physical and logical provisioning     

A generalized framework for distributed power control in wireless networks

Most power control algorithms that aim at hitting a signal-to-interference ratio (SIR) target fall within Yates' framework. However, for delay-tolerable applications, it is unnecessary to maintain the SIR at a certain level all the time. To maximize throughput, one should increase one's power when the interference level is low, and the information transmission rate is adjusted accordingly by adaptive modulation and coding techniques. This approach is called opportunistic communications. In this paper, we generalize Yates' result and establish a new framework, which is applicable to systems supporting opportunistic communications and with heterogeneous service requirements. Simulation results show that our proposed algorithm yields significant improvement in throughput when compared with the conventional target tracking approach.     

业务光网络中光服务等级协定的研究

从业务光网络的角度对比服务等级协定(SLA)定义了光服务等级协定(O-SLA)的框架结构,在此基础上重点分析了O-SLA协商机制并提出一种动态协商的概念,对动态协商机制的实现流程进行了分析研究.随后总结了O-SLA得以有效实施的关键技术,并提出一种支持区分服务的O-SLA实施流程,此流程对于向端用户提供可定制化的光层业务提供了一种新思路.     

A survey and performance evaluation of decentralized aggregation schemes for autonomic management

Over the last few years, autonomic network and service management has emerged as a serious alternative to traditional management approaches. In these systems, distributed entities, called autonomic managers, perform monitoring and control operations in an autonomous and decentralized way. The monitoring consists of providing indicators on the state of the system. Several monitoring solutions have been proposed to enable autonomic managers to obtain a partial or complete knowledge of an indicator through aggregation processes. Such a profusion of solutions raises important questions regarding the choice of an aggregation scheme in a particular operational context and for a particular management information because each class of solution presents different benefits and weaknesses. That is why, in this paper, we present the result of our study of decentralized aggregation schemes for autonomic network and service monitoring. The contribution is twofold: (i) a survey of decentralized aggregation schemes based on a refined taxonomy; and (ii) the results of an evaluation campaign we performed to compare typical aggregation schemes. These results highlight the context, in terms of the managed network behaviour as well as information dynamics, in which each aggregation scheme outperforms the others, thus helping autonomic management system designers in choosing the best scheme for their management purpose. Copyright © 2014 John Wiley & Sons, Ltd     

COPS-SLS usage for dynamic policy-based QoS management over heterogeneous IP networks

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.     

WiMAX系统终端软件设计

基于IEEE 802.16e标准,给出了WiMAX终端软件系统的总体架构设计方案,包括其软件系统划分及数据处理流程。根据系统总体要求,实现了部分IEEE 802.16e标准中的必备功能,包括数据面的基本数据收发、MAC PDU构造、分片组包、ARQ和上行调度,以及控制面的测距、基本能力协商、注册、数据连接/服务流建立等。     

Toward Efficient Service-Level QoS Provisioning in Large-Scale 802.11-Based Networks

Along with recent advances in mobile networking and portable computing technologies, there is a trend in the telecommunications industry toward the development of efficient ubiquitous systems that can provide a set of bandwidth-intensive and real-time services to multiple users while supporting their full mobility. Large-scale deployment of 802.1 1-based technologies will play an integral part in the construction of such ubiquitous wireless mobile systems. A challenging task in the development of such networks is efficient provisioning of QoS-enabled services for mobile users. In this context, we propose a scheme that constantly monitors the overall network performance to perform admission control and traffic conditioning at the 802.11-based access points and mobile terminals. The focus is on service-level fairness, where different flows from the same traffic class can still receive the same QoS level even if they have different bit rates. Furthermore, given the mobility of users, the success of any resource allocation and admission control model depends on the continuity of QoS guarantees across different WLANs. This article proposes a dynamic service level agreement negotiation protocol that allows mobile terminals to perform handoffs between different WLANs while maintaining the agreed level or service. End users also can change their service levels in response to changes in network conditions.