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Internet service providers increasingly wish to monitor the performance of customer traffic within their networks. This paper addresses the problem of scalably performing one-way loss measurements across specific network paths. Our solution addresses the issue of scale by exploiting measurement features of the deployed network infrastructure to a large degree. There are three components. Firstly, GRE tunneling is used to control the path followed by measurement traffic in the network. Secondly, innovative probing methods, coupled with standard measurement capabilities, such as NetFlow, are used to isolate the performance of groups of measurement packets. Thirdly, we exploit and extend tomographic inference methods in order to extract the performance of probe traffic on customer paths within the network. This combination yields a powerful yet lightweight method to determine customer performance within the network.

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Disjoint-Path Facility Location: Theory and Practice

Breslau

Diakonikolas²,

Duffield

et al. 2011

2011 Proceedings of the Thirteenth Workshop on Algorithm Engineering and Experiments (ALENEX)

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This paper is a theoretical and experimental study of two related facility location problems that emanated from networking. Suppose we are given a network modeled as a directed graph G = (V, A), together with (not-necessarily-disjoint) subsets C and F of V , where C is a set of customer locations and F is a set of potential facility locations (and typically C ⊆ F). Our goal is to find a minimum sized subset F ′ ⊆ F such that for every customer c ∈ C there are two locations f 1 , f 2 ∈ F ′ such that traffic from c to f 1 and to f 2 is routed on disjoint paths (usually shortest paths) under the network's routing protocols. Although we prove that this problem is impossible to approximate in the worst case even to within a factor of 2 log 1−ǫ n for any ǫ > 0 (assuming no NPcomplete language can be solved in quasipolynomial time), we show that the situation is much better in practice. We propose three algorithms that build solutions and determine lower bounds on the optimum solution, and evaluate them on several large real ISP topologies and on synthetic networks designed to reflect real-world LAN/WAN network structure. Our main algorithms are (1) an algorithm that performs multiple runs of a straightforward randomized greedy heuristic and returns the best result found, (2) a genetic algorithm that uses the greedy algorithm as a subroutine, and (3) a new "Double Hitting Set" algorithm. All three approaches perform surprising well, although, in practice, the most cost-effective approach is the multirun greedy algorithm. This yields results that average

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VMScope

Cited by 8 publications

References 8 publications

Measurements of Data Plane Reliability and Performance

Measurements of Data Plane Reliability and Performance

GRE Encapsulated Multicast Probing: A Scalable Technique for Measuring One-Way Loss

Disjoint-Path Facility Location: Theory and Practice

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