Distributed soft policy enforcement by swarm intelligence; application to loadsharing and protection

Managing complex heterogeneous computer and telecommunication systems is challenging. One promising management concept for such systems is policy based management. However, it is common to interpret policies strictly and resort to centralized decisions to resolve policy conflicts. Centralization is undesirable from a dependability point of view. Swarm intelligence based on sets of autonomous “ant-like” mobile agents, where control is distribute among the agents, has been applied to several challenging optimization and tradeoff problems with great success. This paper introduces and demonstrates how a set of such ant-like mobile agents can be designed to find near optimal solutions for the implementation of a set of potentially conflicting policies. Solutions are found in a truly distributed manner, hence an overall more dependable/robust system is obtained. The enforcement of the policies is soft in the sense that it is probabilistic and yields a kind of “best effort” implementation. To demonstrate the feasibility of the overall concept, a case study is presented where ant-like mobile agents are designed to implement load distribution and conflict free back-up policies.     

Towards semantic web-based management of security services

Policy-based management of distributed system has become a commonly accepted approach for such systems. However, there are a number of open technical issues that might put large-scale deployment of policy-based management techniques at risk. They include automated policy translation (i.e., refinement from abstract business goals to final configurations); development of integrated policy architectures for network, service and application management, and dynamic service creation; and methods for policy conflict detection and resolution. Regarding this last issue, there exist some relevant efforts in the security area, but they are still in the design phase and it is not clear how flexible and powerful they will become when they deal with different kinds of security-related policies and scenarios. This article provides the main ideas behind the semantically enriched specification of security policies and describes an automated process for doing conflict detection on these policies.     

Knowledge-Based Policy Conflict Analysis in Mobile Social Networks

Mobile social networks give online social networking sites the capabilities to extend their services to mobile device users. Smart phones and tablets allow users to interact with each other when they are moving. Policy-based management simplifies the management of interaction functionalities by establishing policies to control various activities involved in these functionalities. To detect and resolve potential dynamic conflicts between the rules and configurations from different administrative domains, a knowledge-based policy analysis framework is proposed in this paper. It incorporates relationships between different elements in policy rules into temporal logic using a knowledge extension, which makes dynamic policy conflict analysis more accurate. A prototype system for mobile social networks is implemented to illustrate the capability of this framework.     

An introduction to policy management

Policy management is an all-encompassing term that describes how the QoS policies applied to a network would be managed. This paper illustrates the complexity of policy management, and goes on to explain how the end result of installing a new network policy only happens after a range of both business and network rules are followed. Business rules check that the requested policy is permitted under the customer’s agreed service package and other non-network variables such as the time of day, while network rules include access control functions that check the network has sufficient free capacity before admitting the new policy. Various examples illustrate the importance of co-ordinating policies across the network and that the most appropriate policy is installed in the first place. Poor policy management may result in a next generation network appearing to offer a worse quality of service than the completely best-effort network it is replacing.     

Policy hierarchies for distributed systems management

Distributed system management, involves monitoring the activity of a system, making management decisions and performing control actions to modify the behavior of the system. Most of the research on management has concentrated on management mechanisms related to network management or operating systems. However, in order to automate the management of very large distributed systems, it is necessary to be able to represent and manipulate management policy within the system. These objectives are typically set out in the form of general policies which require detailed interpretation by the system managers. The paper explores the refinement of general high-level policies into a number of more specific policies to form a policy hierarchy in which each policy in the hierarchy represents, to its maker, his plans to meet his objectives and, to its subject, the objectives which he must plan to meet. Management action policies are introduced, and the distinction between imperatival and authority policies is made. The relationship of hierarchies of imperatival policies to responsibility, and to authority policies, is discussed. An outline approach to the provision of automated support for the analysis of policy hierarchies is provided, by means of a more formal definition of policy hierarchy refinement relationships in Prolog     

The technical and legal dangers of code-based fair use enforcement

Digital rights management (DRM) mechanisms, built upon trusted computing platforms, promise to give content providers the ability to impose rules reliably and deterministically on end-user experiences with information resources ranging from literary works and scholarly publications to a vast array of entertainment content. DRM represents just the first wave of a class of technologies that aspire not only to implement copyright-protecting usage controls on computing devices, but increasingly to take on the enforcement of a broader set of organizational and public policies. The paper focuses on policy enforcement in the specific context of content use. It reviews the concepts and architecture of policy specification and enforcement, citing examples from the special case of DRM, and provides a detailed discussion of how usage control policies are evaluated in DRM systems. Since the expression and interpretation of policies is only one "layer" of the general problem of persistent policy enforcement, we consider the role that trusted computing systems can play in ensuring that computing agents interpret policies in reliable and deterministic ways. Finally, we consider the challenges inherent in the construction of technical mechanisms that mimic social policies.     

Efficient Resource Allocation for Policy-Based Wireless/Wireline Interworking

This paper proposes efficient resource allocation techniques for a policy-based wireless/wireline interworking architecture, where quality of service (QoS) provisioning and resource allocation is driven by the service level agreement (SLA). For end-to-end IP QoS delivery, each wireless access domain can independently choose its internal resource management policies to guarantee the customer access SLA (CASLA), while the border-crossing traffic is served by a core network following policy rules to meet the transit domain SLA (TRSLA). Particularly, we propose an engineered priority resource sharing scheme for a voice/data integrated wireless domain, where the policy rules allow cellular-only access or cellular/WLAN interworked access. By such a resource sharing scheme, the CASLA for each service class is met with efficient resource utilization, and the interdomain TRSLA bandwidth requirement can be easily determined. In the transit domain, the traffic load fluctuation from upstream access domains is tackled by an inter-TRSLA resource sharing technique, where the spare capacity from underloaded TRSLAs can be exploited by the overloaded TRSLAs to improve resource utilization. Advantages of the inter-SLA resource sharing technique are that the core network service provider can freely design the policy rules that define underload and overload status, determine the bandwidth reservation, and distribute the spare resources among bandwidth borrowers, while all the policies are supported by a common set of resource allocation techniques.     

An Approach to Seeking Policy Disputes Based on Dispute Cycle Avoidance and Configuration Guideline

The Border Gateway Protocol (BGP) is the de facto interdomain routing protocol used to exchange network reachability information between ASes in the global Internet. However, Varadhan et al. [19] has shown that the conflict of BGP routing policies can cause BGP to diverge. This paper presents an approach to seek the set of conflict routing policies based on dispute cycle avoidance. The stable paths problem, a static formalism that captures the semantics of interdomain routing protocol, provides the theoretical foundation for this approach. And this approach draws on the simple path vector protocol to identify the dispute cycles that cause routing oscillation first, and then queries which routing policies lead to these cycles in a distributed manner. Finally, it determines conflict routing policies based on dispute cycle avoidance. Moreover, we present a method to determine the severity level of dispute routing policies based on AS relationships and configuration guidelines of routing policy presented by Gao and Rexford [4]. And this method can help Network administrators determine the top-priority routing policies to be fixed and improve the efficiency of debugging routing policies. In addition, a simulation instance is given in order to explain results of this method.     

防火墙策略冲突检测及冲突策略可视化

为了检测防火墙策略中的所有冲突,避免修改冲突时引入新冲突,文中采用对规则进行分割来检测冲突。其中,冲突检测包括3个部分:防火墙策略分割、对分割的结果进行分析和计算,以及冲突域提取。同时,为了对冲突规则以及产生冲突的原因进行分析,文中采用网格的可视化方法实现了对防火墙规则之间以及规则与冲突域之间的关系。采用这种技术能够提高管理员发现、分析和修改策略冲突的效率和准确性,并通过实验验证了该方法的有效性。     

Attribute-based lightweight reconfigurable access control policy

Aiming at the severe challenges of access control policy redundancy and conflict detection,the efficiency of access control policy evaluation in complex network environment,an attribute-based lightweight reconfigurable access control policy was proposed.Taking the attribute-based access control policy as an example,the attribute-based access control policy was divided into multiple disjoint atomic access control rules according to the operation type,subject attribute,object attribute,and environment attribute in the access control policy.Complex access control policies were constructed through atomic access control rules and an algebraic expression formed by AND,OR logical relationships.A method for redundancy and collision detection of atomic access control rules was proposed.A method was proposed for decompose a complex access control policy into equivalent atomic access control rules and an algebraic expression.The method for redundancy and collision detection of complex access control policies were proposed through redundancy and collision detection of equivalent atomic access control rules and algebraic expressions.From time complexity and space complexity,the efficiency of the equivalent transformation access control policy was evaluated.It showes that the reconstruction method for access control policy greatly reduces the number,size and complexity of access control policy,improves the efficiency of access control policy redundancy and collision detection,and the efficiency of access control evaluation.     

一种基于RBAC的多域间角色映射机制

针对基于角色的访问控制(RBAC)的多域系统,提出了一套安全而高效的满足策略合成与冲突解决要求的角色映射机制。通过引入对等权限概念,明确了策略合成的目标;支持了基于混合角色层次的RBAC系统上的多域间策略合成;提出了权限非上升原则和角色映射的3个属性来使得角色映射细粒度化,同时获得安全的全局策略。所提出的算法在策略合成过程中,自动检测和避免了策略冲突,合成算法的复杂度低,便于实际应用。     

Characterizing the behaviour of high-speed interconnection systems with distributed control

In this paper, we consider very high-speed, connection-oriented communication in distributed systems where each node system has a limited-size queue for connection requests. An important example of this type of system is an HIPPI-based interconnection system of a supercomputer complex. For such systems, we present a distributed connection management policy and propose several possible service disciplines. We develop an analytic model to evaluate the interconnection system under different system configurations, connection management policies, and service disciplines. In this evaluation, we consider separately systems where nodes want to communicate with any one of a pool of identical servers, and systems where a node needs to access a specific one of a set of distinct servers.     

面向社会网络的个性化隐私策略定义与实施

为了实现社会网络中个性化隐私保护,提出了支持个性化隐私偏好授权模型,采用基于一阶逻辑隐私偏好描述语言,表达用户个性化隐私需求;引入基于主体属性的访问者－角色授权规则和基于客体标签的角色－权限指派规则,解决了动态用户授权和细粒度访问权限指派问题;分析了隐私策略冲突各种情况,实现了基于Prolog逻辑编程的策略一致性自动验证;设计了面向社会网络个性化隐私策略管理和实施中间件,将个性化隐私策略管理有效地集成到对既有资源的访问控制系统中,实验表明策略冲突分析具有良好的执行效率。     

Access Control Policy Analysis and Access Denial Method for Cloud Services

Personal cloud computing is an emerging trend in the computer industry. For a sustainable service, cloud computing services must control user access. The essential business characteristics of cloud computing are payment status and service level agreement. This work proposes a novel access control method for personal cloud service business. The proposed method sets metadata, policy analysis rules, and access denying rules. Metadata define the structure of access control policies and user requirements for cloud services. The policy analysis rules are used to compare conflicts and redundancies between access control policies. The access denying rules apply policies for inhibiting inappropriate access. The ontology is a theoretical foundation of this method. In this work, ontologies for payment status, access permission, service level, and the cloud provide semantic information needed to execute rules. A scenario of personal data backup cloud service is also provided in this work. This work potentially provides cloud service providers with a convenient method of controlling user access according to changeable business and marketing strategies.     

Integrated conflict management programs emerge as an organization development strategy

Conflict management systems … [are] apparently an emerging phenomenon in American corporations. … In many companies with strong ADR policies, ADR isn't simply a set of techniques added to others the company uses but represents a change in the company's mindset about how it needs to manage conflict.”     

美国宽带政策对我国的启示

对比分析了近期中国和美国的宽带政策变化,提出了深化电信普遍服务机制、建立与监管政策配套的信息化管理手段、完善5G配套建设模式及规范等政策建议,希望通过消除政策障碍和推进政策制度化、规范化、流程化,加快各类宽带设施部署.     

Domains and policies in third generation mobile network managementsystems

The efficiency and manageability of network management architectures, are based largely upon structuring principles, which make intensive use of concepts such as management domains and management policies. The paper discusses architectural aspects of management for the universal mobile telecommunication system (UMTS), and suggests a model for the structuring of the managed system into management domains, and the subsequent control of it through policies. Explicit statements are made concerning the representation of the policy structure. Furthermore, the assistance that standardized support managed objects can provide in policy implementation is examined. Finally, a schema for capturing the interrelations between policy objects is provided, assisting in this way the effective management of the policy structure     

Automatic rule installation in case of policy change in software defined networks

Software Defined Networking (SDN) has emerged recently as a new network architecture. It implements both control and management planes at centralized controller and data plane at forwarding devices. Therefore, SDN helps to simplify network management and improves network programmability. Changes in network policies occur frequently by making modifications at controller. However, in existing approaches, the rules installed at switches before policy change at controller are not modified. This can cause violation of network policy by packets. To address this problem, this paper presents a new approach that stores the rules generated at controller. After detecting the change in policy, the proposed approach finds the rules that will be affected by policy change by examining stored rules at controller. Then the affected rules are removed from the forwarding devices. Simulation results reveal that our proposed approach provides less packets violation ratio and normalized traffic overhead as compared to existing approach. Therefore, the proposed approach increases network performance and efficiency.     

Performance analysis of power management policies in wireless networks

It has long been recognized that energy conservation usually comes at the cost of degraded performance such as longer delay and lower throughput in stand-alone systems and communication networks. However, there have been very few research efforts in quantifying such trade-offs. In this paper, we develop analytical models to characterize the relationships among energy, delay and throughput for different power management policies in wireless communication. Based on the decision when to put nodes to low-power states, we divide power management policies into two categories, i.e., 1) time-out driven and 2) polling-based. M/G/1/K queues with multiple vacations and an attention span are used to model time-out driven policies while transient analysis is applied to derive the state transition probability in polling-based systems. We find that For time-out driven power management policies, the "optimal" policy exhibits a threshold structure, i.e., when the traffic load is below certain threshold, a node should switch to the low-power state whenever possible and always remain active otherwise. From our analysis, contrary to general beliefs, polling-based policies such as the IEEE 802.11 PSM are not energy efficient for light traffic load.