Design and Deployment of a Passive Monitoring Infrastructure

Abstract-We measure and analyze the single-hop packet delay through operational routers in the Sprint Internet protocol (IP) backbone network. After presenting our delay measurements through a single router for OC-3 and OC-12 link speeds, we propose a methodology to identify the factors contributing to single-hop delay. In addition to packet processing, transmission, and queueing delay at the output link, we observe the presence of very large delays that cannot be explained within the context of a first-in first-out output queue model. We isolate and analyze these outliers.Results indicate that there is very little queueing taking place in Sprint's backbone. As link speeds increase, transmission delay decreases and the dominant part of single-hop delay is packet processing time. We show that if a packet is received and transmitted on the same linecard, it experiences less than 20 s of delay. If the packet is transmitted across the switch fabric, its delay doubles in magnitude. We observe that processing due to IP options results in single-hop delays in the order of milliseconds. Milliseconds of delay may also be experienced by packets that do not carry IP options. We attribute those delays to router idiosyncratic behavior that affects less than 1% of the packets. Finally, we show that the queueing delay distribution is long-tailed and can be approximated with a Weibull distribution with the scale parameter = 0 5 and the shape parameter = 0 6 to 0.82. Index Terms-Link utilization, queueing delay, single-hop delay measurement.

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“…We have collected day-long packet traces, and analyzed them off-line. Details about the measurement infrastructure can be found in [6].…”

Section: Delay Measurementmentioning

confidence: 99%

“…We have designed a measurement system that addresses the first two of the above difficulties, and deployed it in the Sprint tier-1 Internet protocol (IP) backbone network to collect packet traces with accurate timestamps [6]. We use optical splitters to capture and timestamp every packet traversing a link (see details in Section II).…”

mentioning

confidence: 99%

Measurement and analysis of single-hop delay on an IP backbone network

Papagiannaki

Moon

Fraleigh³

et al. 2003

IEEE J. Select. Areas Commun.

150

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“…At the same time, the direct per-packet inline measurement conducted at the destination of an instrumented path does not require offline measurement data to be shipped and correlated over the network, as it is the case with passive monitoring systems. The data correlation required from two distinct passive monitoring devices in order to measure a characteristic of the interconnecting path (such as the unidirectional delay) equals twice the amount of the perpacket captured data plus the capture library header that normally stores measurement data such as timestamps [5]. This would at least sum up to 2x56 bytes per packet for IPv4 and 2x76 bytes per packet for IPv6 (to include network and transport layer headers and e.g.…”

Section: Measurement Data Overheadmentioning

confidence: 99%

“…Active measurement systems that directly probe a path to assess its temporal performance characteristics are based either on synthetic traffic that does not necessarily reflect the performance of the actual datacarrying traffic [3], or on transport/application-layer mechanisms that render them applicable only to a subset of the traffic [4]. At the same time, passive monitoring infrastructures that observe the operational traffic at a single point in the network need to correlate and post-process immense amounts of data before conducting a conclusive performance measurement, and they therefore operate at long timescales [5][6] [7]. Active and passive measurement mechanisms cannot be easily extended to operate at an Internet-wide scale and in an always-on manner, mainly due to the overhead they incur either on the network (e.g.…”

Section: Introductionmentioning

confidence: 99%

Low-Overhead End-to-End Performance Measurement for Next Generation Networks

Pezaros

Hoerdt

Hutchison

2011

IEEE Trans. Netw. Serv. Manage.

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Abstract-Internet performance measurement is commonly perceived as a high-cost control-plane activity and until now it has tended to be implemented on top of the network's forwarding operation. Consequently, measurement mechanisms have often had to trade relevance and accuracy over non-intrusiveness and cost effectiveness.In this paper, we present the software implementation of an inline measurement mechanism that uses native structures of the Internet Protocol version 6 (IPv6) stack to piggyback measurement information on data-carrying traffic as this is routed between two points in the network. We carefully examine the overhead associated with both the measurement process and the measurement data, and we demonstrate that direct two-point measurement has minimal impact on throughput and on system processing load. The results of this paper show that adequately engineered measurement mechanisms that exploit selective processing do not compromise the network's forwarding efficiency, and can be deployed in an always-on manner to reveal the true performance of network traffic over small timescales.

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“…Single-point passive measurement systems suffer from their inherent promiscuous operation and the immense amount of traffic they need to process. Even when operating completely independently from the network nodes using additional dedicated hardware, they do not perform a direct measurement; rather they monitor operational traffic and hence conclusive measurement can only be conducted offline, after significant amounts of data have been correlated and synthesised [8].…”

Section: Introductionmentioning

confidence: 99%

High-speed, in-band performance measurement instrumentation for next generation IP networks

2010

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Abstract. Facilitating always-on instrumentation of Internet traffic for the purposes of performance measurement is crucial in order to enable accountability of resource usage and automated network control, management and optimisation. This has proven infeasible to date due to the lack of native measurement mechanisms that can form an integral part of the network"s main forwarding operation. However, Internet Protocol version 6 (IPv6) specification enables the efficient encoding and processing of optional per-packet information as a native part of the network layer, and this constitutes a strong reason for IPv6 to be adopted as the ubiquitous next generation Internet transport.In this paper we present a very high-speed hardware implementation of in-line measurement, a truly native traffic instrumentation mechanism for the next generation Internet, which facilitates performance measurement of the actual data-carrying traffic at small timescales between two points in the network. This system is designed to operate as part of the routers" fast path and to incur an absolutely minimal impact on the network operation even while instrumenting traffic between the edges of very high capacity links. Our results show that the implementation can be easily accommodated by current FPGA technology, and real Internet traffic traces verify that the overhead incurred by instrumenting every packet over a 10 Gb/s operational backbone link carrying a typical workload is indeed negligible.

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Design and Deployment of a Passive Monitoring Infrastructure

Cited by 69 publications

References 9 publications

Measurement and analysis of single-hop delay on an IP backbone network

Measurement and analysis of single-hop delay on an IP backbone network

Low-Overhead End-to-End Performance Measurement for Next Generation Networks

High-speed, in-band performance measurement instrumentation for next generation IP networks

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