Showing papers on "Network management published in 2003"

Public Management and Educational Performance: The Impact of Managerial Networking

Abstract: Policies are implemented in complex networks of organizations and target populations. Effective action often requires managers to deal with an array of actors to procure resources, build support, coproduce results, and overcome obstacles to implementation. Few large-n studies have examined the crucial role that networks and network management can play in the execution of public policy. This study begins to fill this gap by analyzing performance over a five-year period in more than 500 U.S. school districts using a nonlinear, interactive, contingent model of management previously developed by the authors. The core idea is that management matters in policy implementation, but its impact is often nonlinear. One way that public managers can make a difference is by leveraging resources and buffering constraints in the program context. This investigation finds empirical support for key elements of the network-management portion of the model. Implications for public management are sketched.

System and method for detecting unauthorized wireless access points

Abstract: Unauthorized wireless access points are detected by configuring authorized access points and mobile units to listen to all wireless traffic in its cell and report all detected wireless devices to a monitor. The monitor checks the reported devices against a list of authorized network devices. If the reported wireless device is not an authorized device, the monitor determines if the reported device is connected to the network. If the reported device is connected to the network and is not an authorized device, the monitor alerts the network operator or network manager of a rogue device connected to the network and attempts to locate and isolate the rogue device.

Automatically inferring patterns of resource consumption in network traffic

Abstract: The Internet service model emphasizes flexibility -- any node can send any type of traffic at any time. While this design has allowed new applications and usage models to flourish, it also makes the job of network management significantly more challenging. This paper describes a new method of traffic characterization that automatically groups traffic into minimal clusters of conspicuous consumption. Rather than providing a static analysis specialized to capture flows, applications, or network-to-network traffic matrices, our approach dynamically produces hybrid traffic definitions that match the underlying usage. For example, rather than report five hundred small flows, or the amount of TCP traffic to port 80, or the "top ten hosts", our method might reveal that a certain percent of traffic was used by TCP connections between AOL clients and a particular group of Web servers. Similarly, our technique can be used to automatically classify new traffic patterns, such as network worms or peer-to-peer applications, without knowing the structure of such traffic a priori. We describe a series of algorithms for constructing these traffic clusters and minimizing their representation. In addition, we describe the design of our prototype system, AutoFocus and our experiences using it to discover the dominant and unusual modes of usage on several different production networks.

Automatic device assignment through programmable device discovery for policy based network management

Abstract: A technique for automatically identifying and assigning devices to device proxies in a policy based network management system is described. Each device proxy registers a filter with the device discovery. The filter may identify one or more characteristics of devices and may also include a communications protocol to be used by the device discovery to communicate with devices. The device discovery, preferably using the specified protocol, obtains device specific information and then identifies devices in the network that match the filters. The device discovery notifies each device proxy of which devices match the proxy's filter. Each device proxy updates its list of devices that it can policy manage based on the notification from the device discovery. Control policies are distributed from a policy server to each of the device proxies. Each device proxy then sends a policy to one or more devices to be policy managed.

Policy-Based Network Management: Solutions for the Next Generation

Abstract: Policy-Based Network Management (PBNM) systems enable business rules and procedures to be translated into policies that configure and control the network and its services. Those who manage network systems are aware that this approach can benefit both network management as well as the development of applications that use network services; however, the details surrounding these systems has been obscured by marketing hype, numerous acronyms, and theoretical complexities. "Policy-Based Network Management: Solutions for the Next Generation" cuts through the hype surrounding PBNM and makes it approachable for those who really need to understand what it has to offer. The author, founder of the IETF Policy Framework working group, discusses system requirements, information models, and system components for Policy-Based Management. He also provide practitioners with a resource for developing and/or incorporating PBNM systems. As network systems become larger and more complex, creating policies for them has become a crucial step in the management of network systems, and this book is a welcome addition to this exciting approach. It presents a completely new approach to PBNM that unites the business, system, and implementation spheres. As the basis for examples and discussion, it uses the DEN-ng information model, an easy-to-understand open standard tied closely to eTOM and NGOSS. It introduces the Ponder system, then examines Ponder extensions designed to enhance the structure of high-level policies and their application in a PBNM system. It is filled with examples illustrating how policies are most effectively used in a PBNM system and what new directions PBNM is likely to take.

Inside the Matrix: Integrating the Paradigms of Intergovernmental and Network Management

Abstract: The basic research concepts of intergovernmental and network management are examined with regard to blending the two into a unified theory of collaborative management. A substantial literature in both fields has emerged and is ripe for conceptually enhancing interorganizational management in the public sector. The collaborative management concepts forwarded emanate from the authors' comprehensive study of collaborative public management in 237 cities. The major concerns that are found to be ready for knowledge unification include: (1) multiple network complexity and the emergence of governance through policy networks, (2) strategic behavior and its implementation through networks, (3) the role of government institutions in network governance, and (4) the use of myriad policy instruments and multiorganizational activity. Each of these research arenas are representative of the kind of knowledge base that can be blended and extended to help public managers understand how to operate in the vertical/h...

Methods and apparatus for monitoring local network traffic on local network segments and resolving detected security and network management problems occurring on those segments

Abstract: A system for providing network security through manipulating data connections and connection attempts over a data-packet-network between at least two network nodes is provided. The system includes a system host machine, a first software application residing on the host machine for detecting and monitoring connection activity, a data store for storing connection related data, and a second software application for emulating one or more end nodes of the connections or connection attempts. In a preferred embodiment the system uses the detection software to detect one or more pre-defined states associated with a particular connection or connection attempt including states associated with data content transferred there over and performs at least one packet generation and insertion action triggered by the detected state or states, the packet or packets emulating one or more end nodes of the connection or connection attempt to cause preemption or resolution of the detected state or states.

Mobility support in wireless Internet

Abstract: The tremendous advancement and popularity of wireless access technologies necessitates the convergence of multimedia (audio, video, and text) services on a unified global (seamless) network infrastructure. Circuit-switched proprietary telecommunication networks are evolving toward more cost-effective and uniform packet-switched networks such as those based on IP. However, one of the key challenges for the deployment of such wireless Internet infrastructure is to efficiently manage user mobility. To provide seamless services to mobile users, several protocols have been proposed over the years targeting different layers in the network protocol stack. In this article we present a cross-layer perspective on the mobility protocols by identifying the key features of their design principles and performance issues. An analysis of the signaling overhead and handoff delay for some representative protocols in each layer is also presented. Our conclusion is that although the application layer protocol is worse than the protocols operating in the lower layers, in terms of handoff delay and signaling overhead, it is better suited as a potential mobility solution for the next-generation heterogeneous networks, if we consider such factors as protocol stack modification, infrastructure change, and inherent operational complexity.

Automatic configuration of the network devices via connection to specific switch ports

Abstract: A method and system for automatically configuring devices in a network is disclosed. A network management software application is provided that enables a user to associate policy settings with physical locations in the network. During an operational mode of the network management application, the application automatically detects when a network device is plugged into the network, and determines a location of the device in the network. The device is then automatically configured based on the policy settings associated with the corresponding location.

System and method for synchronizing the configuration of distributed network management applications

Abstract: A change management system to synchronize the configuration of network management applications. Traditional network management systems are maintained by hand-entering device lists into individual network management applications with no common-ties between the different applications. Whenever a network management application is changed or upgraded, it frequently becomes necessary to insure that the upgrade is populated throughout the network in order for devices to talk to one another in an error free way. The present invention is a system and method that automates the change management process in a real-time using a two-way communications model that permits a central database to affect changes on all or some network management applications/systems in the field, while also allowing those same field systems to affect the central database thereby reducing the time required for updating and monitoring a system when device changes take place.

Mobile agents in distributed network management

Abstract: By helping to disperse centralized network management tasks to subnet hosts, mobile agent technology helps conserve network bandwidth and improves management efficiency by decreasing network traffic.

Routing on a curve

Abstract: Relentless progress in hardware technology and recent advances in sensor technology, and wireless networking have made it feasible to deploy large scale, dense ad-hoc networks. These networks together with sensor technology can be considered as the enablers of emerging models of computing such as embedded computing, ubiquitous computing, or pervasive computing. In this paper, we propose a new paradigm called trajectory based forwarding (or TBF), which is a generalization of source based routing and Cartesian routing. We argue that TBF is an ideal technique for routing in dense ad-hoc networks. Trajectories are a natural namespace for describing route paths when the topology of the network matches the topography of the physical surroundings in which it is deployed which by very definition is embedded computing.We show how simple trajectories can be used in implementing important networking protocols such as flooding, discovery, and network management. Trajectory routing is very effective in implementing many networking functions in a quick and approximate way, as it needs very few support services. We discuss several research challenges in the design of network protocols that use specific trajectories for forwarding packets.

Rule-based network management approaches

Abstract: A method is disclosed for detecting symptoms in a network infrastructure, combining one or more symptoms into a problem, then optionally applying detailed diagnosis to the network elements experiencing the problems, ultimately providing detailed problem determination.

An IP-based QoS architecture for 4G operator scenarios

Abstract: This article describes a global QoS architecture for multimedia traffic in mobile heterogeneous environments. This architecture supports both multiple access networks and multiple service provider scenarios. The architecture is able to provide QoS per user and per service, implementing the notion of a user profile associated network management in the case of heterogeneous and mobile network access is presented based on cooperative association between QoS brokers and authentication, authorization, accounting, and charging systems. The overall exchange of messages is exemplified for the case of a field test with specific optimizations for voice traffic.

Ontologies: giving semantics to network management models

Abstract: The multiplicity of network management models may imply in some scenarios the use of multiple management information languages defining the resources to be managed. Each language has a different level of semantic expressiveness, which is not easily measurable. Also, these management information models cannot be easily integrated due to the difficulty of translation of the semantics they contain. The article proposes the use of ontologies as a new approach to improving the semantic expressiveness of management information languages. Ontologies are currently used, for instance, to provide Web pages and Web services the semantics they usually lack (known today as the semantic Web). Applying ontologies to management information languages can also be useful for integration of information definitions specified by different management languages and adding behavior information to them.

Secure remote management appliance

Abstract: A computer network management system with an embedded processor, an analog communication means and a digital interface for network management provides a system for remotely and securely managing a network. Backup power in the form of an uninterrupted power supply, or other power means as appropriate, allows the modem to provide power outage notification to a remote site. The system further provides authentication and authorization capabilities for security purposes.

Physical topology discovery for large multisubnet networks

Abstract: Knowledge of the up-to-date physical (i.e., layer-2) topology of an Ethernet network is crucial to a number of critical network management tasks, including reactive and proactive resource management, event correlation, and root-cause analysis. Given the dynamic nature of today's IP networks, keeping track of topology information manually is a daunting (if not impossible) task. Thus, effective algorithms for automatically discovering physical network topology are necessary. In this paper, we propose the first complete algorithmic solution for discovering the physical topology of a large, heterogeneous Ethernet network comprising multiple subnets as well as (possibly) dumb or uncooperative network elements. Our algorithms rely on standard SNMP MIB information that is widely supported in modern IP networks and require no modifications to the operating system software running on elements or hosts. Furthermore, we formally demonstrate that our solution is complete for the given MIB data; that is, if the MIB information is sufficient to uniquely identify the network topology then our algorithm is guaranteed to recover it. To the best of our knowledge, ours is the first solution to provide such a strong completeness guarantee.

Apparatus and method for offering connections between network devices located in different home networks

Abstract: A network connection apparatus for communicating between a network device located in a first private network and a second private network located outside the first private network. The apparatus includes an address acquisition module capable of acquiring a public IP address of a network management device from a DNS based on a domain name of the network management device of the second private network is provided. A connection management module is provided that is capable of forming a P2P connection to the network device if there is a request for a connection to the second private network from the network device. The connection management module is further capable of forming a virtual private network tunnel with the second private network based on the public IP address transferred from the address acquisition module. The connection management module is further capable of transferring to the network device a private IP address used in the second private network.

System and method for correlating traffic and routing information

Abstract: In one aspect, it is realized that changes in routing configuration (and therefore network topology) may have an effect on how data is forwarded in a communication network. More particularly, it is realized the changes in the control plane have a statistical effect on information tracked in the data plane, and this relation may be used by a network manager in monitoring the network and determining a control plane cause of a data plane forwarding effect. For instance, a change in BGP routing information (control plane information) may affect the data forwarded by a router based on the changed BGP routing information (e.g., next hop data may be forwarded to a different BGP router attached to another physical port). A system and method are provided that correlate control plane and data plane information to support root cause analysis functions.

Method and apparatus for monitoring and displaying routing metrics of a network

Abstract: The invention includes an apparatus and method for displaying path metrics associate with nodes and links within a network. The method includes determining path metric values associated with the network. The method further includes displaying only the path metric values that fall within a predetermined set. The predetermined set can be adjustable by a network manager. The predetermined set can include an initial default value and be additionally adjusted by a network manager. The predetermined set associated with a particular node can be based upon a redundancy of paths available to the particular node.

Measuring bottleneck bandwidth of targeted path segments

Abstract: Accurate measurement of network bandwidth is crucial for network management applications as well as flexible Internet applications and protocols which actively manage and dynamically adapt to changing utilization of network resources. Extensive work has focused on two approaches to measuring bandwidth: measuring it hop-by-hop, and measuring it end-to-end along a path. Unfortunately, best-practice techniques for the former are inefficient, and techniques for the latter are only able to observe bottlenecks visible at end-to-end scope. In this paper, we develop end-to-end probing methods which can measure bottleneck bandwidth along arbitrary, targeted subpaths of a path in the network, including subpaths shared by a set of flows. We evaluate our technique through extensive ns simulations, then provide a comparative Internet performance evaluation against hop-by-hop techniques. We also describe a number of applications which we foresee as standing to benefit from solutions to this problem, ranging from network troubleshooting and capacity provisioning to optimizing the layout of application-level overlay networks to optimized replica placement.

Policy Quality of Service (QoS) Information Model

Abstract: This document presents an object-oriented information model for representing Quality of Service (QoS) network management policies. This document is based on the IETF Policy Core Information Model and its extensions. It defines an information model for QoS enforcement for differentiated and integrated services using policy. It is important to note that this document defines an information model, which by definition is independent of any particular data storage mechanism and access protocol.

Experiences with monitoring OSPF on a regional service provider network

Abstract: This paper presents the results from a detailed, experimental study of OSPF an intra-domain routing protocol, running on a mid-size regional Internet service provider. Using multiple, distributed probes running custom monitoring tools, we collected continuous protocol information for a full year. We use this data to analyze the health of the network including the amount, source, duration and periodicity of routing instability. We found that information from external routing protocols produces significant levels of instability within OSPF. We also examine the evolution of the routing topology over time, showing that short term changes are incremental and that the long term trend shows constant change. Finally, we present a set of detailed investigations into several large scale anomalies. These anomalies demonstrate the significant impact external routing protocols have on OSPF. In addition, they highlight the need for new network management tools that can incorporate information from routing protocols.

Flexible and adaptive QoS control for distributed real-time and embedded middleware

Abstract: Computing systems are increasingly distributed, real-time, and embedded (DRE) and must operate under highly unpredictable and changeable conditions. To provide predictable mission-critical quality of service (QoS) end-to-end, QoS-enabled middleware services and mechanisms have begun to emerge. However, the current generation of commercial-off-the-shelf middleware lacks adequate support for applications with stringent QoS requirements in changing, dynamic environments. This paper provides two contributions to the study of adaptive middleware to control DRE applications. It first describes how priority- and reservation-based OS and network QoS management mechanisms can be coupled with standards-based, off-the-shelf distributed object computing (DOC) middleware to better support dynamic DRE applications with stringent end-to-end real-time requirements. It then presents the results of experimentation and validation activities we conducted to evaluate these combined OS, network, and middleware capabilities. Our work integrates currently missing low-level resource control capabilities for end-to-end flows with existing capabilities in adaptive DRE middleware and sets the stage for further advances in fine-grained precision management of aggregate flows using dynamic adaptation techniques.

Distributed network monitoring with bounded link utilization in IP networks

Abstract: Designing optimal measurement infrastructure is a key step for network management. In this work we address the problem of optimizing a scalable distributed polling system. The goal of the optimization is to reduce the cost of deployment of the measurement infrastructure by identifying a minimum poller set subject to bandwidth constraints on the individual links. We show that this problem is NP-hard and propose three different heuristics to obtain a solution. We evaluate our heuristics on both hierarchical and flat topologies with different network sizes under different polling bandwidth constraints. We find that the heuristic of choosing the poller that can poll the maximum number of unpolled nodes is the best approach. Our simulation studies show that the results obtained by our best heuristic is close to the lower bound obtained using LP relaxation.

Out-of-band remote management station

Abstract: A computer network management system with an embedded processor, an analog communication means and a digital interface for network management provides a system for remotely and securely managing a network. Backup power in the form of an uninterrupted power supply, or other power means as appropriate, allows the modem to provide power outage notification to a remote site. The system further provides authentication and authorization capabilities for security purposes.

An adaptive management architecture for ad hoc networks

Abstract: Ad hoc networks, where mobile nodes communicate via multihop wireless links, facilitate network connectivity without the aid of any preexisting networking infrastructure. The intrinsic attributes of ad hoc networks, such as dynamic network topology, limited battery power, constrained wireless bandwidth and quality, and large number of heterogeneous nodes, make network management significantly more challenging than stationary and wired networks. In particular, the conventional client/server-based manager/agent management paradigm falls short of addressing these issues. We describe the Guerrilla management architecture to facilitate adaptive and autonomous management of ad hoc networks. The management capability of Guerrilla is scalable to accommodate the sheer number and heterogeneity of nodes, autonomous and survivable to adapt to network dynamics, and economical to minimize management overhead.

Standardized active measurements on a tier 1 IP backbone

Abstract: Synthetic or active measurements are often used to characterize IP performance; however, it is rare to find them used to resolve problems in an operational setting. We show that the active monitoring system in the AT&T IP backbone provide's a comprehensive view of network performance that is complementary to traditional element level monitoring, making it an integral part of network management. This paper discusses the design and implementation of these active measurements in the network. We continuously monitor "path-level" performance metrics such as round-trip delay, loss, jitter, and reordering events to proactively detect impairments. Our system relies on the promotion of key metrics to the operational displays, while maintaining a rich set of statistics for analyzing rare and unforeseen events. This timely information enables us to react,quickly to performance degradation, avoiding any sustained effect on customer applications. The results also help us understand the network's ability to support time-sensitive application performance. Selected "interesting" events observed are presented, including detection of degradation caused by low-level bit errors on a physical link, detection of route changes on the network and their impact on real-time applications, and finally detection of reordering caused by forwarding loops.