Policy conflict analysis for diffserv quality of service management

Policy-based management provides the ability to (re-)configure differentiated services networks so that desired Quality of Service (QoS) goals are achieved. This requires implementing network provisioning decisions, performing admission control, and adapting bandwidth allocation to emerging traffic demands. A policy-based approach facilitates flexibility and adaptability as policies can be dynamically changed without modifying the underlying implementation. However, inconsistencies may arise in the policy specification. In this paper we provide a comprehensive set of QoS policies for managing Differentiated Services (DiffServ) networks, and classify the possible conflicts that can arise between them. We demonstrate the use of Event Calculus and formal reasoning for the analysis of both static and dynamic conflicts in a semi-automated fashion. In addition, we present a conflict analysis tool that provides network administrators with a user-friendly environment for determining and resolving potential inconsistencies. The tool has been extensively tested with large numbers of policies over a range of conflict types

Quality of service control in IP networks using Fuzzy Logic for policy condition evaluation

This paper presents the architecture of a policy- based network management system designed specifically for Quality of Service management, where high level business policies are modeled as ECA (Event-Condition-Action) rules. Specifically, the system is mainly based on the policy architecture being proposed by the IETF (Internet Engineering Task Force), DMTF (Distributed Management Task Force), and TMF (TeleManagement Forum) standardization bodies. This work proposes a novel approach for policy condition evaluation using fuzzy logic. The fuzzy controller has the ability to examine policy conditions differently from default condition analyzers that employ simple conditions formed by a set of (IFs, ANDs and ORs), allowing the consideration and correlation of several input variables before taking decisions for the execution of policy actions. The system have been implemented and evaluated over a test bed network formed by Cisco® routers

An adaptive policy-based framework for network services management

This paper presents a framework for specifying policies for the management of network services. Although policy-based management has been the subject of considerable research, proposed solutions are often restricted to condition-action rules, where conditions are matched against incoming traffic flows. This results in static policy configurations where manual intervention is required to cater for configuration changes and to enable policy deployment. The framework presented in this paper supports automated policy deployment and flexible event triggers to permit dynamic policy configuration. While current research focuses mostly on rules for low-level device configuration, significant challenges remain to be addressed in order to:a) provide policy specification and adaptation across different abstraction layers; and, b) provide tools and services for the engineering of policy-driven systems. In particular, this paper focuses on solutions for dynamic adaptation of policies in response to changes within the managed environment. Policy adaptation includes both dynamically changing policy parameters and reconfiguring the policy objects. Access control for network services is also discussed.Accepted versio

User-Centric Quality of Service Provisioning in IP Networks

The Internet has become the preferred transport medium for almost every type of communication, continuing to grow, both in terms of the number of users and delivered services. Efforts have been made to ensure that time sensitive applications receive sufficient resources and subsequently receive an acceptable Quality of Service (QoS). However, typical Internet users no longer use a single service at a given point in time, as they are instead engaged in a multimedia-rich experience, comprising of many different concurrent services. Given the scalability problems raised by the diversity of the users and traffic, in conjunction with their increasing expectations, the task of QoS provisioning can no longer be approached from the perspective of providing priority to specific traffic types over coexisting services; either through explicit resource reservation, or traffic classification using static policies, as is the case with the current approach to QoS provisioning, Differentiated Services (Diffserv). This current use of static resource allocation and traffic shaping methods reveals a distinct lack of synergy between current QoS practices and user activities, thus highlighting a need for a QoS solution reflecting the user services. The aim of this thesis is to investigate and propose a novel QoS architecture, which considers the activities of the user and manages resources from a user-centric perspective. The research begins with a comprehensive examination of existing QoS technologies and mechanisms, arguing that current QoS practises are too static in their configuration and typically give priority to specific individual services rather than considering the user experience. The analysis also reveals the potential threat that unresponsive application traffic presents to coexisting Internet services and QoS efforts, and introduces the requirement for a balance between application QoS and fairness. This thesis proposes a novel architecture, the Congestion Aware Packet Scheduler (CAPS), which manages and controls traffic at the point of service aggregation, in order to optimise the overall QoS of the user experience. The CAPS architecture, in contrast to traditional QoS alternatives, places no predetermined precedence on a specific traffic; instead, it adapts QoS policies to each individual’s Internet traffic profile and dynamically controls the ratio of user services to maintain an optimised QoS experience. The rationale behind this approach was to enable a QoS optimised experience to each Internet user and not just those using preferred services. Furthermore, unresponsive bandwidth intensive applications, such as Peer-to-Peer, are managed fairly while minimising their impact on coexisting services. The CAPS architecture has been validated through extensive simulations with the topologies used replicating the complexity and scale of real-network ISP infrastructures. The results show that for a number of different user-traffic profiles, the proposed approach achieves an improved aggregate QoS for each user when compared with Best effort Internet, Traditional Diffserv and Weighted-RED configurations. Furthermore, the results demonstrate that the proposed architecture not only provides an optimised QoS to the user, irrespective of their traffic profile, but through the avoidance of static resource allocation, can adapt with the Internet user as their use of services change.France Teleco

Quality of Service (QoS) in Enterprise WAN Networks

Enterprise IT organizations started to face issues related to managing applications over the slow speed Wide Area Network (WAN) circuits a few years ago with the appearance and use of file-sharing applications over their WANs and/or Internet between headquarters and branch offices. The pain has continued to grow with introduction of mission critical transactional type data along with voice and video traffic over these networks. For this very reason several techniques were developed and implemented over the years by the vendors and service providers to help the Enterprise organization cope with these problems. This field project report provides an overview of Quality of Service (QoS) and its implementation in Enterprise Networks for Engineering Managers. The author will discuss the best practices around developing designs for architectures already in place, as well as the business and technical challenges that are faced by Engineering Managers in enterprise organizations when deploying QoS. While the project focuses on QoS implementation of WAN, similar concepts can be used for any type of implementation throughout the network. The author will first address the issue of bandwidth utilization and how its use has increased in recent years, what type of applications are driving it and the issues enterprise organizations are having in managing it. Next, the various industry standard solutions available to tackle this issue and the advantages of deploying them in the network will be discussed. Recommendations on the use of Project Planning guidelines to implement this critical project within the company and strategic steps that can be used to accomplish the goal will follow. Finally, cost analysis will show that increasing the bandwidth on the WAN can simply add cost to the enterprise organizations in most cases, whereas the proper use of QoS can help the organization reduce cost while utilizing the existing circuits while delivering the same level of service. The author recommends the use of QoS in networks to manage traffic but does not rule out the possibility of increasing bandwidth in the enterprise network or the combination of both

QoS SOLUTIONS FORVIDEOCONFERENCING

This project is intended to gain knowledge and apply the theory leamt about the need of QoS in videoconferencing and the various options available. Today's conferencing applications are now IP friendly, it can run on either dedicated lines (like ISDN or telephone lines) or IP networks. However, as most network administrators know, conferencingapplications can wreak havoc on unprepared corporate networks. The key to successfully deploying conferencing applications is the activation of Quality of Service (QoS). QoS refers to a network's ability to reliably and consistently provide a certain level of throughput and performance. QoS for conferencing typically involves network availability, bandwidth, end-to-end delay, jitter, and packet loss. Simply stated, if the network doesn't conform to the minimum requirements in any of these areas, the conferences are doomed to fail. QoS can be achieved in a variety of ways, including over-provisioning (deploying additional bandwidth), data prioritization, and the use of QoS-enabled overlay or converged networks. Organizations have two main options for deploying QoS within their organizations; convergence or overlay. Convergence requires the use of QoS-capable WAN links throughout the organization. In many cases, this requires a fork-lift upgrade and migration of all network resources, which can place convergence out of reach of many cost-sensitive organizations. On the other hand, overlay networks allow a step-by-step migration from a non-QoS to a QoS network without the high cost and inherent risk of major network reconfigurations. In this way, overlay networks are a first step toward convergenc

Security and management policy specification

Accepted versio