Analysis of measured single-hop delay from an operational backbone network

Papagiannaki, Konstantina; Moon, Sang Heup; Fraleigh, C.; Thiran, Patrick; Tobagi, Fouad A.; Diot, Christophe

doi:10.1109/infcom.2002.1019298

Cited by 89 publications

(83 citation statements)

References 10 publications

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“…The monitoring systems are GPS synchronized and offer a maximum clock skew of 6 s. Details on the clock synchronization and possible errors in the accuracy of our delay measurements can be found in [8]. Consistency in the results obtained on more than 30 links, connected to different routers in all four PoP, across multiple days, gives us confidence in the accuracy of the single hop delay measurements presented in this paper.…”

Section: Delay Measurementsupporting

confidence: 52%

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

Papagiannaki

Moon

Fraleigh³

et al. 2003

IEEE J. Select. Areas Commun.

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149

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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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Section: Delay Measurementsupporting

confidence: 52%

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

Papagiannaki

Moon

Fraleigh³

et al. 2003

IEEE J. Select. Areas Commun.

Self Cite

149

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show abstract

“…Existence of SYN packets improves the accuracy of RTT estimation, as we use the three-way handshake for our RTT estimation. For those flows we use IP and TCP headers of each packet collected at the capturing points Core and Border and detect loss, if any, through the border router as in [13]. Figure 5(a) shows the cumulative distribution of loss rates weighted by the flow's size: the cumulative distribution function on the y-axis represents the proportion in the total traffic volume as in Figure 4.…”

Section: Packet Lossmentioning

confidence: 99%

Operating a Network Link at 100%

Lee

et al. 2011

Passive and Active Measurement

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Abstract. Internet speed at the edge is increasing fast with the spread of fiberbased broadband technology. The appearance of bandwidth-consuming applications, such as peer-to-peer file sharing and video streaming, has made traffic growth a serious concern like never before. Network operators fear congestion at their links and try to keep them underutilized while no concrete report exists about performance degradation at highly utilized links until today. In this paper, we reveal the degree of performance degradation at a 100% utilized link using the packet-level traces collected at our campus network link. The link has been fully utilized during the peak hours for more than three years. We have found that per-flow loss rate at our border router is surprisingly low, but 30 ∼ 50 msec delay is added. The increase in delay results in overall RTT increase and degrades user satisfaction for domestic web flows. Comparison of two busy traces shows that the same 100% utilization can result in different amount of performance loss according to the traffic conditions. This paper stands as a good reference to the network administrators facing future congestion in their networks.

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“…The higher the link utilization, the higher the queueing delay [25]. In the current Internet, an access link is considered to be overloaded when its average utilization is greater than 80% [26], [27]. Thus, we set Λ = 0.8.…”

Section: Total Flows On a Logical Linkmentioning

confidence: 99%