Understanding user experience on mobile devices with the ICSI NetalyzrNarseo Vallina-Rodriguez, Srikanth Sundaresan, Christian Kreibich, Nicholas Weaver and Vern Paxson!ICSI-UC Berkeley!!Moritz Steiner !Akamai

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Opinions are those of the presenter, and not of the funders

Project sponsored by:

Where I’m coming from

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• ICSI: International Computer Science Institute - Berkeley

• PhD in Computer Science at the University of Cambridge (UK, 2013) in collaboration with Telefonica Research. Research on mobile OSs and cellular networks!

• Member of ICSI-Networking and Security group since July 2013

• More info:

• Personal page: http://www.icsi.berkeley.edu/~narseo

• Group page: http://www.icsi.berkeley.edu/icsi/groups/networking

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The Internet is becoming mobile

Where is the actual bottleneck in mobile

networks?

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Carte Figurative des Pertes Successives en hommes de l’Armée Francaise dans la Campagne de Russie (1812-1813)

!Charles Minard.1869

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End-to-end model?

What is the cause of actual performance?

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The ICSI Netalyzr for Android

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• User-run tool to diagnose connectivity characteristics from the edge of the Internet

• Checks for behavioral anomalies, network properties and security issues for everybody

• Started in 2009 as a JAVA applet (1.4M sessions in 170 countries)

• Native Android version since November 2013 (22K installs in 120 countries)

• Research outcome: IMC’10, FOCI’11, SATIN’11, PAM’12/13, CONEXT’14

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The ICSI Netalyzr Story

IP CORE (USER PLANE)!!

DNS RESOLVERS HIDDEN PROXIES

NETWORK TOPOLOGY AND PEERING SHARED INFRASTRUCTURE

TLS INTERCEPTION IPV6 AND DNSSEC SUPPORT

NATs DETAILED LATENCY TESTS

HANDSET HW AND MISCONFIGURATION!!

APN CONFIGURATIONS BUFFERS

CERTIFICATE ROOTSTORE SYSTEM CLOCK

Netalyzr for AndroidRADIO TECHNOLOGY (CONTROL PLANE)!

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!1. Middleboxes deployment and behavior!!2. IPv6 support!!3. Layer 8: Infrastructure sharing and mobile

virtual network operators (MVNO)

The analysis: !Looking beyond the radio link!

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!!!!!!!!!

DATA PLANE

The IP core of cellular networks

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UE!!!!

CONTROL PLANE

NODE B!/ RNC

GGSN!/P-GW

SGSN!/S-GW

INTERNETIP COREN!A!T

DNS !Resolver

PROXY!/CachePDP Context !

(APN configuration)

The impact of network topology

Inappropriate network deployment can double DNS lookup time!

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3G

4G

Median DNS Lookup Time (ms)

0 70 140 210 280

DNS Before CGNDNS After CGN

DNS ProxyTCP:21 (FTP)TCP:22 (SSH)

TCP:25 (SMTP)TCP:80 (HTTP)

TCP:110 (POP3)TCP:143 (IMAP)

TCP:443 (HTTPS)TCP:587 (SMTP)

TCP:993 (TLS IMAP)TCP:995 (TLS POP3)

TCP:1194 (VPN)TCP:1723 (PPTP VPN)

TCP:5060 (SIP)TCP:6881 (TORRENT)

TCP:9001 (TOR)

Percentage of operators

0 20 40 60 80

WorldwideUSA

Hidden proxies on cellular networks

Headermodification

Contentmodification

Header (*)forwarding

HTTP header enforcement

Non-HTTP traffic filters

Percentage of operators

0 17.5 35 52.5 70

WorldwideUSA

What are HTTP proxies actually doing?

Questions for you …

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• 11% of sessions on IPv6. It requires handset and network support (APN settings)

!• Only 9 operators* in 6 countries: US, Canada, Poland, Italy,

Australia, and Sweden !

• No significant latency difference with IPv4 observed yet !

!

How is IPv6 transition done in practice and what issues does it cause?

… but whose IP core?

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• Mobile network operators (MNO) vs. virtual mobile network operators (MVNO)

• Infrastructure sharing between MNOs:

• Reduce deployment costs

• Roaming implementations: Home routed vs. Local Breakout

Layer 8

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A partial view of US cellular networks as seen by Netalyzr

VERIZON

AT&TSPRINT

T-MOBILE

BOOST

REPUBLICVIRGIN

GO SMARTFAMILY MOBILE

SIMPLE MOBILE

METROPCS

TRACFONE

WDSPCo

Hosted Data

Solutions

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STRAIGHTTALK

Heterogeneous network properties!

Operator 1 (3G) Operator 2 (3G)

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Invalid Host Field

DNS Proxy

Header/ContentModification

HTTP Enforcement

Percentage of sessions

0 25 50 75 100

Percentage of sessions

0 25 50 75 100

Home NetworkRoaming

Lessons learnt

• Measuring mobile performance is a difficult multidimensional analysis

• Network properties, and services are not homogeneous even within a single operator

• Middleboxes can affect performance and bias server-side performance measurements: measure from the edge for fidelity

• Layer 8 must be taken into account: roaming implementations and types of MVNO define the IP core

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Future Work• Characterize mobile ecosystem (MNO and MVNO) at

a global-scale

• Get better insight on business relationships and network sharing agreements

• Characterization of IP core: location of DNS resolvers and proxies and their implications

• IPv6 - IPv4 performance

• Impact of mobile infrastructure on CDN performance and cloud services

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Try Netalyzr and tell us what you’d like to know

about your network!

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narseo@icsi.berkeley.edu !

netalyzr-help@icsi.berkeley.edu http://www.netalyzr.icsi.berkely.edu/publications

Mobile app designFront-end!(ICSI)

Back-ends!(Amazon EC2)

JSon - based report

Android activity

Background service

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App reviews and feedback

:) :(24

MVNOs vs MNO

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Netalyzr Facts (as of Sept. 2014)

• 1.4M total sessions executed in more than 170 countries

• Android version: 22K installs and 41K sessions executed

• Research outcome:

• Test-suite description and analysis of the state of the Internet [IMC’10]

• DNS interpositioning for error traffic monetization [USENIX FOCI’11]

• DNS status and performance [SATIN’11]

• UPnP vulnerabilities on home gateways and proxy deployments at a world-wide scale [PAM’12 and PAM’13]

• Analysis of Root certificates on Android handsets in the wild [CoNEXT’14]

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Roaming implementationsPDP CONTEXT

(APN SETTINGS)

VISITING NETWORK

UE

DATA-PLANE

DNSResolver

IP CORE

Proxy NAT

PDN

1. HOME ROUTED:

PDP CONTEXT(APN SETTINGS)

DATA-PLANE

PDN

VISITING NETWORK

UE

2. LOCAL BREAKOUT:

DNSResolver

IP CORE

Proxy NAT

CONTROL-PLANE

SGSNS-GW

CONTROL-PLANE

BILLING ANDAUTHENTICATION

GGSNP-GW

HOME NETWORK

RNCeNB

CONTROL-PLANE

SGSNS-GW

CONTROL-PLANE

BILLING ANDAUTHENTICATION

GGSNP-GW

HOME NETWORK

RNCeNB

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… and network deployment!3G 4G CDMA2000

100

60.339.70.499.6

0.299.8

1.598.5

100

100100

19.580.5

100

20.4 2.975.8 0.9

100100

100

100

4060595

88.911.1

100

2575

11.8 2.584.5 1.2

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100100

44.655.4100

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100

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2575

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67.432.6

100

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964

100

100

100

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59.140.9

OTHERSSWISSCOM (CH)

T−MOBILE (DE)VIRGIN (FR)

3 (UK)SPRINT (US)

SFR (FR)AT&T (US)

BOUYGUES (FR)ORANGE (FR)VERIZON (US)

T−MOBILE (US)FREE (FR)

OTHERSJOE (FR)

VIRGIN (FR)VIRGIN (US)BOOST (US)SPRINT (US)

SFR (FR)AT&T (US)

BOUYGUES (FR)ORANGE (FR)

METROPCS (US)T−MOBILE (US)

FREE (FR)

Hom

e Network

MVN

O/R

oaming

ED C D EDP ED C D EDP ED C D EDPTOPOLOGY

25 50 75 100Percentage of sessions per operatorand 3GPP standard

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The impact of network topology

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0.25

0.50

0.75

1.00

0 500 1000 1500DNS lookup time for uncached names (ms)

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Inappropriate network topology can double DNS lookup time!

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3G

4G

Median DNS Lookup Time (ms)

0 150 300 450 600

DNS Before CGNDNS After CGN