235 research outputs found
Tuning active monitoring in multiservice IP networks
Comunicação apresentada "Performance Modelling and Evaluation of Heterogeneous Networks (HET-Nets 04), 2, Ilkley, U.K., July 2004.This paper explores the use of edge-to-edge active monitoring to control simultaneously multiple QoS parameters in multi-service IP networks, while reducing the effects of intrusion on real traffic. Considering a multi-class domain where traffic is controlled at network boundaries based on feedback from on-line measurements, the present work is centered on obtaining adequate per class in-band probing streams so that each class behaviour is correctly captured, even if more than a QoS metric is under control. In this way, we investigate distinct properties of probing patterns and cross-check probing and passive measurement results in order to assess and tune probing effectiveness. To enhance probing ability to sense multiple metrics, we explore Active Queue Management effects on probes and their different probability of reaching the network boundary. The results show that, while IPTD can be easily captured using a very low probing rate, matching ipdv and IPLR is not straightforward. However, we found that choosing a convenient drop precedence for probing packets, the simultaneous estimation of these QoS metrics can be significantly improved
Inter-organizational fault management: Functional and organizational core aspects of management architectures
Outsourcing -- successful, and sometimes painful -- has become one of the
hottest topics in IT service management discussions over the past decade. IT
services are outsourced to external service provider in order to reduce the
effort required for and overhead of delivering these services within the own
organization. More recently also IT services providers themselves started to
either outsource service parts or to deliver those services in a
non-hierarchical cooperation with other providers. Splitting a service into
several service parts is a non-trivial task as they have to be implemented,
operated, and maintained by different providers. One key aspect of such
inter-organizational cooperation is fault management, because it is crucial to
locate and solve problems, which reduce the quality of service, quickly and
reliably. In this article we present the results of a thorough use case based
requirements analysis for an architecture for inter-organizational fault
management (ioFMA). Furthermore, a concept of the organizational respective
functional model of the ioFMA is given.Comment: International Journal of Computer Networks & Communications (IJCNC
Next generation network provider architecture demonstrator
This paper presents a next generation network demonstrator currently under deployment in Aveiro. The demonstrator supports mobile IP with fast handovers with integrated QoS and AAAC issues considerations. A monitoring system provides network information adequate for QoS management, and a specially built QoS Broker is able to manage multiple types of Access Routers. The demonstrator has been tested with some applications, and is currently under refinement
Building a Standard Measurement Platform
Network management is achieved through a large number of disparate solutions for different technologies and parts of the end-to-end network. Gaining an overall view, and especially predicting the impact on a service user, is difficult. Recently, a number of proprietary platforms have emerged to conduct end-to-end testing from user premises; however, these are limited in scale, interoperability, and the ability to compare like-for-like results. In this article we show that these platforms share similar architectures and can benefit from the standardization of key interfaces, test definitions, information model, and protocols. We take the SamKnows platform as a use case and propose an evolution from its current proprietary protocols to standardized protocols and tests. In particular, we propose to use extensions of the IETF's IPFIX and NETCONF/YANG in the platform. Standardization will allow measurement capabilities to be included on many more network elements and user devices, providing a much more comprehensive view of user experience and enabling problems and performance bottlenecks to be identified and addressed.Publicad
Implementation and Analysis of the IP Measurement Protocol (IPMP)
The increased size and complexity of the Internet necessitates a more substantial measurement protocol than is currently available. This work explores the IP Measurement Protocol, providing background information, covering the development of a reference implementation, and finally comparing its accuracy, overhead, and ease of implementation to the current generation of protocols used in network measurement. Vmware, a hardware simulation application, was used to simulate a network on which to test IPMP, as well as compare it to current generation tools. Ipmp_ping, a tool written to test IPMP, was pitted against ping and traceroute in order to attain round trip time, one-way delay, and path discovery measurements. The accuracy and overhead of these tools were compared to each other. Although ipmp_ping had more overhead than ping when measuring round trip time, it was just as accurate and more capable. Ipmp_ping proved to be much more efficient than traceroute with similar accuracy. Overall, ipmp_ping was as accurate and had negligibly more or significantly less overhead than the tools it was compared to while providing more functionality and being easy to implement
Integrated monitoring of multi-domain backbone connections -- Operational experience in the LHC optical private network
Novel large scale research projects often require cooperation between various
different project partners that are spread among the entire world. They do not
only need huge computing resources, but also a reliable network to operate on.
The Large Hadron Collider (LHC) at CERN is a representative example for such a
project. Its experiments result in a vast amount of data, which is interesting
for researchers around the world. For transporting the data from CERN to 11
data processing and storage sites, an optical private network (OPN) has been
constructed. As the experiment data is highly valuable, LHC defines very high
requirements to the underlying network infrastructure. In order to fulfil those
requirements, the connections have to be managed and monitored permanently. In
this paper, we present the integrated monitoring solution developed for the
LHCOPN. We first outline the requirements and show how they are met on the
single network layers. After that, we describe, how those single measurements
can be combined into an integrated view. We cover design concepts as well as
tool implementation highlights.Comment: International Journal of Computer Networks & Communications (IJCNC
Providing cost-effective QoS monitoring in multiservice networks
http://www.ngi2009.eu/In multiservice networks, QoS monitoring needs to be carried out in a per-class basis so that each service class measuring requirements and behavior are met and sensed properly. Facing the shortage of off-the-shelf class-based monitoring solutions, this work is focused on the development of a flexibly QoS monitoring tool oriented to multiservice networks. In this context, after discussing main QoS monitoring issues, we propose a flexible QoS monitoring Java application, totally user parameterized and supporting service differentiation. Benefiting from an edge-to-edge design perspective, this service-oriented tool is able to make a periodic evaluation of relevant QoS metrics for each service class, on an intra-domain or end-to-end path basis. Monitoring results, stored in a MySQL database, are useful to drive both online and offline traffic engineering and service management tasks
A Comparison of Performance between TFRC and UDP over a Mobile IP Network
In this project we will study three performance metrics (packet loss, packet delay and jitter) of two different transport layer protocols over a Mobile IP Network. The researcher will be implementing TFRC and UDP in the Mobile IP Network, to identify which protocols could support mobility. Network Simulation NS-2 was proposed for implementing previous items and to present and interpret the results
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