Understanding user experience on mobile devices with the ICSI Netalyzr Narseo Vallina-Rodriguez, Srikanth Sundaresan, Christian Kreibich, Nicholas Weaver and Vern Paxson! ICSI-UC Berkeley! ! Moritz Steiner ! Akamai Project sponsored by: Opinions are those of the presenter, and not of the funders 1 Where I’m coming from • 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 2 The Internet is becoming mobile 3 Where is the actual bottleneck in mobile networks? 4 End-to-end model? Carte Figurative des Pertes Successives en hommes de l’Armée Francaise dans la Campagne de Russie (1812-1813) ! Charles Minard.1869 5 What is the cause of actual performance? 6 The ICSI Netalyzr for Android 7 The ICSI Netalyzr Story • 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 8 Netalyzr for Android RADIO TECHNOLOGY (CONTROL PLANE)! 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 9 The analysis: ! Looking beyond the radio link! ! 1. Middleboxes deployment and behavior! ! 2. IPv6 support! ! 3. Layer 8: Infrastructure sharing and mobile virtual network operators (MVNO) 10 The IP core of cellular networks ! PROXY! !! !! /Cache !! N! A! ! IP CORE T ! DNS ! Resolver PDP Context ! (APN configuration) UE NODE B! / RNC ! ! SGSN! ! /S-GW ! DATA PLANE GGSN! /P-GW CONTROL PLANE 11 INTERNET The impact of network topology DNS Before CGN DNS After CGN 3G 4G 0 70 140 210 280 Median DNS Lookup Time (ms) Inappropriate network deploymentt, and the presence of DNS proxies can double DNS lookup time! 12 Hidden proxies on cellular networks DNS Proxy TCP: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) Worldwide USA 0 20 40 60 Percentage of operators 80 What are HTTP proxies actually doing? Header modification Content modification Header (*) forwarding Worldwide USA HTTP header enforcement Non-HTTP traffic filters 0 17.5 35 52.5 Percentage of operators 70 Questions for you … • 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? 15 … but whose IP core? 16 Layer 8 • Mobile network operators (MNO) vs. virtual mobile network operators (MVNO) • Infrastructure sharing between MNOs: • Reduce deployment costs • Roaming implementations: Home routed vs. Local Breakout 17 A partial view of US cellular networks as seen by Netalyzr FAMILY MOBILE GO SMART WDSPCo SIMPLE MOBILE VERIZON T-MOBILE METRO PCS STRAIGHT TALK AT&T Hosted Data Solutions SPRINT BOOST TRACFONE VIRGIN 18 REPUBLIC Heterogeneous network properties! Operator 1 (3G) Operator 2 (3G) Invalid Host Field DNS Proxy Header/Content Modification HTTP Enforcement 0 25 50 75 100 Percentage of sessions 0 25 50 75 Percentage of sessions Home Network Roaming 19 100 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 serverside 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 20 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 21 Try Netalyzr and tell us what you’d like to know about your network! narseo@icsi.berkeley.edu ! netalyzr-help@icsi.berkeley.edu http://www.netalyzr.icsi.berkely.edu/publications 22