is it really worth to peer at ixps?dilallo/presentations/itisreallyworthtopeeratixps.pdfwe exploited...

Roma Tre University

Is It Really Worth to Peer at IXPs?

Marco Di Bartolomeo Giuseppe Di Battista Roberto di Lallo Claudio Squarcella

Nautilius Mediterranean Exchange Point (NaMeX)

ISCC 2015

UNIVERSITÀ DEGLI STUDI

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Introduction to IXPsInternet eXchange Points (IXPs) are infrastructures used by Internet Service Providers (ISPs) to exchange traffic between their ASes


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Known Benefits


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Known Benefits• Lower distances

and locality of traffic


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Known Benefits• Lower distances

and locality of traffic

• Better QoS for the User


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Related Work (Selection)• N. Chatzis, G. Smaragdakis, A. Feldmann, and W. Willinger,

“There is more to ixps than meets the eye”, SIGCOMM Comput. Commun. 2013

• A. Gupta, L. Vanbever, M. Shahbaz, S. P. Donovan, B. Schlinker, N. Feamster, J. Rexford, S. Shenker, R. Clark, and E. Katz-Bassett, “Sdx: A software defined internet exchange”,in Proc. SIGCOMM 2014

• M. Ahmad and R. Guha,“A tale of nine internet exchange points: Studying path latencies through major regional ixps”, in Local Computer Networks (LCN), 2012


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Motivation and Contribution


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Motivation and ContributionMOTIVATION

• A quantitative analysis on the impact of IXPs on key performance indicators is missing

• To our knowledge, all existing works use, at least partially, simulated data

• Comparing a path traversing an IXP with one that does not is hard without direct control of traffic flows


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Motivation and ContributionMOTIVATION

• A quantitative analysis on the impact of IXPs on key performance indicators is missing

• To our knowledge, all existing works use, at least partially, simulated data

• Comparing a path traversing an IXP with one that does not is hard without direct control of traffic flows

OUR CONTRIBUTION

• Supported by several ISPs, we compare key performance indicators using real-world measurements on IXP and non-IXP paths


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Side Motivation: DepeeringSome major ISPs have canceled all peerings (depeering) at the IXPs, justifying such decision in terms of :

• Cost reduction • Improvement of the quality of services (QoS)


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But…


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QoS InvestigationInvestigate the impact that IXPs have on the QoS

USED METRICS


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QoS Investigation

Round Trip Time

Investigate the impact that IXPs have on the QoSUSED METRICS


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Hop Count

QoS Investigation

Round Trip Time



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Hop Count

QoS Investigation

Round Trip Time

Packet Loss



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Jitter

Hop Count

QoS Investigation

Round Trip Time

Packet Loss



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Traffic Locality InvestigationInvestigate the impact that IXPs have on keeping local the

local traffic


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A Case of StudyThe Italian Internet and the Italian main Internet eXchange Points


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Measuring SystemWe exploited the distributed infrastructure of RIPE Atlas, an Internet measurement network based on thousands of devices (probes), deployed all around the world.


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Experiment CISCritical and most visited Internet Sites

Critical Internet Sites


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Experiment CISCritical and most visited Internet Sites

Most visited Internet Sites

• We selected the sites that are most visited by italians according to the Alexa ranking

• We filtered the ones hosted in Italy

• Finally we selected the first 100


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Experiment CIS: Setting

• Targets: • 50 critical Internet services • 100 most visited sites

• Duration of the experiment: 4 hours • Frequency of measurements:

• 6 pings per hour • 2 traceroutes per hour


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Experiment CIS: ResultsMeasurement: Round Trip Delay

Targets: Critical Internet sites

0 %

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0 20 40 60 80 100 120 140 160

Cu

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Round trip delay [ms]

Probes not traversing IXPsProbes traversing IXPs


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0 %

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6 8 10 12 14 16 18 20 22 24

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Hop count

Probes not traversing IXPsprobes traversing IXPs

Experiment CIS: ResultsMeasurement: Hop count

Targets: Most visited Internet sites


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0

20

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AS174

AS3356

AS8928

AS3257

AS1200

AS2914

AS1299

AS6453

AS8220

AS3549

AS1273

AS20940

AS34419

% o

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ath

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UPSTREAMIXP

Experiment CIS: ResultsMeasurement: Paths traversing foreign (non-Italian) ASes

Targets: Critical Internet sites


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AS174

AS3356

AS2914

AS1299

AS3549

AS6939

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UPSTREAMIXP

Experiment CIS: ResultsMeasurement: Paths traversing foreign (non-European) ASes

Targets: Most visited Internet sites


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Experiment CIS: Discussion• IXPs have a positive effect on keeping local the local

traffic

• As a first observation, paths through IXPs seem to have better performance

• …However these measurements are performed by a variable set of probes, since we don’t have direct control on interdomain routing (i.e., BGP) announcements


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Experiment SBA: SettingSelective BGP Announcements

UPSTREAMUPSTREAM

PARTNERISP

PHASES:UPSTREAM

IXP

ALL

Probe


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UPSTREAMUPSTREAM

PARTNERISP

PHASES:UPSTREAM

IXP

ALL

Probe

Experiment SBA: SettingSelective BGP Announcements


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Partner ISPsFor the second experiment we partnered with 3 providers:

Mc-Link

Italian network operator headquartered in Rome and founded in 1986.

It mainly offers services for the business

industry.

Seeweb


It offers cloud services and web hosting

Unidata


Among the co-founders of the popular IXP

NaMeX


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Average round-trip delay [ms]

Probes choosing upstream (M)Probes choosing IXPs (M)

Probes choosing upstream (F)Probes choosing IXPs (F)

Experiment SBA: ResultsMeasurement: Average Round Trip Delay

Target(s): Inside Seeweb (“M” and “F”)


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Average round-trip delay [ms]

AS 174IXP

Experiment SBA: ResultsMeasurement: Average Round Trip Delay

Target: Inside Seeweb, through upstream AS 174


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Average hop count

Probes choosing upstreamProbes choosing IXPs

Experiment SBA: ResultsMeasurement: Average Hop count

Target: Inside MC-LINK


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5 6 7 8 9 10 11 12 13

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Average hop count

AS 3356IXP

Experiment SBA: ResultsMeasurement: Average Hop count

Target: Inside MCLINK, through upstream AS 3356


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Jitter [ms]

Probes choosing upstreamProbes choosing IXPs

Experiment SBA: ResultsMeasurement: Jitter

Target: Inside Unidata


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Jitter [ms]

AS 3257IXP

Experiment SBA: ResultsMeasurement: Jitter

Target: Inside Unidata, through upstream AS 3257


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Experiment SBA: ResultsMeasurement: Gain on the RTT (per class of probes)


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Gap in average round trip delay [ms]

CAHCustomer

Transit


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Experiment SBA: ResultsMeasurement: Gain on the Hop Count (per class of probes)


0 %

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-10 -9 -8 -7 -6 -5 -4 -3 -2 -1

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Gap in average hop count

CAHCustomer

Transit


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ConclusionsOur experiments put in evidence that peerings exploiting IXPs:

• have a positive effect on key performance indicators

• have the effect of reducing the number of foreign ISPs traversed to reach critical Internet services (keep local the local traffic)


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Future WorkIt would be interesting to:

• extend our experiments considering more performance indicators (e.g. bandwidth)

• cooperate with ISPs and IXPs in other countries to reproduce the experiments, compare the results and generalize the methodology


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Thank you for your [email protected]

mailto:[email protected]

is it really worth to peer at ixps?dilallo/presentations/itisreallyworthtopeeratixps.pdfwe exploited...

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