MonNet – a project for network and traffic monitoring How is SUNET really used? Results of traffic classification on backbone data Wolfgang John and Sven Tafvelin Dept. of Computer Science and Engineering Chalmers University of Technology Göteborg, Sweden
Introduction: Measurement location • 2x 10 Gbit/s (OC-192) • capturing headers only Internet Internet • IP addresses anonymized • tightly synchronized • bidirectional per-flow analysis Stockholm GSIX l a l n a Göteborg o n i o g i e g s GU R e P s R P S I S I Chalmers Other smaller Univ. and Institutes SUNET TrefPunkt 17 2007-11-15
Introduction: Motivation • Problem: – Operators don’t know type of their traffic – How to: • Improve network design and provisioning? • Support QoS support or security monitoring? • Enhance accounting possibilities? • Reveal trends and changes in network applications? SUNET TrefPunkt 17 2007-11-15
Introduction: Motivation (2) • Solution: Network classification – Four approaches in literature: 1. Port numbers + easy to implement - unreliable (P2P, malicious traffic) 2. Packet payloads + accurate - requires updated payload signatures - privacy and legal issues - high processing requirements SUNET TrefPunkt 17 2007-11-15
Introduction: Motivation (3) • Solution: Network classification (contd.) 3. Statistical fingerprinting + no detailed packet information needed - depending on quality of training data - promising, but still immature 4. Connection patterns + no payload required + no training data required - not perfect accuracy SUNET TrefPunkt 17 2007-11-15
Introduction: Overview • Connection classification • Overview of proposed heuristics • Verification of methodology • Results • Traffic volumes • Diurnal patterns • Signaling behavior • Summary of more results SUNET TrefPunkt 17 2007-11-15
Methodology: Traffic Classification • Two articles classify P2P flows according to connection patterns: – Karagiannis et al., 2004 – Perenyi et al., 2006 • Updated classification heuristics: – Refined the heuristics in prior articles – Added new, necessary heuristics SUNET TrefPunkt 17 2007-11-15
Methodology: Proposed Heuristics • Rules based on connection patterns and port numbers – 5 rules for P2P traffic – 10 rules to classify other types of traffic • remove ‘false positives’ from P2P – Rules are applied: • On flows in 10 minute intervals • Independently on all flows and Prioritized when fetched from the database SUNET TrefPunkt 17 2007-11-15
Methodology: Proposed Heuristics (2) – Heuristics for potential P2P traffic (H1-H5) • All traffic to and from potential P2P hosts is marked as P2P traffic • H1: TCP and UDP traffic between IP pair • H2: Well known P2P ports • H3: Re-usage of source port within short time • H4: Non-parallel connections to endpoint (IP/Port) • H5: unclassified, long flows – unclassified by H1-H5 and F1-F10 – more than 1MB in one direction or – duration of more than 10 minutes SUNET TrefPunkt 17 2007-11-15
Methodology: Proposed Heuristics (3) – Heuristics for other traffic (F1-F10) • F1 and F2: Web servers: – parallel connections to Web ports – All traffic to and from Web server is Web-traffic • F3: common services (DNS, BGP) – Equal source and destination port and port<501 • F4: Mail servers: – Hosts receiving traffic on mail ports (smtp, imap, pop) while sending traffic via smtp – All traffic to and from Mail servers is Mail-traffic SUNET TrefPunkt 17 2007-11-15
Methodology: Proposed Heuristics (3) – Heuristics for other traffic (F1-F10) • F5 and F6: Messenger and Gaming – Hosts, connected to by a number of different IPs on well- known messenger, chat or gaming ports within a period of 10 days – All traffic to and from these hosts is messenger or gaming • F7: FTP – Active FTP with initiating port number of 20 • F8: non P2P ports: – Some well-known, privileged port numbers, typically not used by P2P like dns, telnet, ssh, ftp, mail, rtp, bgp … SUNET TrefPunkt 17 2007-11-15
Methodology: Proposed Heuristics (3) – Heuristics for other traffic (F1-F10) • F9: malicious and attack traffic – Scans through IP ranges – Scans through port ranges – DoS or “hammering attacks” to few hosts in high frequency • F10: unclassified, known non-P2P Port – unclassified by H1-H4 and F1-F9 (no connection pattern) – Well known ports including Web, messenger and gaming SUNET TrefPunkt 17 2007-11-15
Verification of proposed heuristic • Comparison of classification for P2P traffic # connections in 10 6 Amount of data in TB SUNET TrefPunkt 17 2007-11-15
2007-11-15 • Application breakdown April 2006 Results: Traffic Volumes SUNET TrefPunkt 17
Results: Traffic Volumes (2) • Application breakdown April till Nov. 2006 SUNET TrefPunkt 17 2007-11-15
Results: Diurnal Patterns • Fractions of P2P data, April till November 1 0.9 0.8 0.7 Linear (2AM P2P data) 0.6 Linear (10AM P2P data) Linear (14PM P2P data) 0.5 Linear (20PM P2P data ) 0.4 0.3 0.2 0.1 0 1143000000 1148000000 1153000000 1158000000 1163000000 SUNET TrefPunkt 17 2007-11-15
Results: Signaling Behavior • Connection establishment for P2P, Web and malicious traffic SUNET TrefPunkt 17 2007-11-15
Summary of Results • Traffic is increasing for TCP and UDP • Highest activity during evening hours • P2P dominating (~90 % of data volume) • P2P peak time at evening and night-time • Web peak time during office hours • Fractions of P2P and Web constant • Malicious traffic constant in absolute numbers • 'background noise' SUNET TrefPunkt 17 2007-11-15
Summary of Results (2) • Major differences in signaling behavior • 43% of TCP P2P connections 1-packet flows (attempts) • 80% of malicious TCP traffic 1-packet flows (scans) • Web traffic behaving ‘nicely‘ • Different TCP options deployment • P2P behaves as expected • Web traffic shows artifacts of client-server patter e.g. popular web-servers neglecting SACK option SUNET TrefPunkt 17 2007-11-15
References • W. John and S. Tafvelin, Analysis of Internet Backbone Traffic and Anomalies observed , ACM IMC07, San Diego, USA, 2007. • W. John and S. Tafvelin, Differences between in- and outbound Internet Backbone Traffic , TNC07, Copenhagen, DK, 2007. Available on: http://www.ce.chalmers.se/~johnwolf • W. John and S. Tafvelin, Heuristics to Classify Internet Backbone Traffic based on Connection Patterns , accepted at IEEE ICOIN08 • W. John and S. Tafvelin and Tomas Olovsson, Trends and Differences in Connection Behavior within Classes of Internet Backbone Traffic , submitted for publication Available on request: johnwolf@ce.chalmers.se or as Paper copy SUNET TrefPunkt 17 2007-11-15
MonNet – a project for network and traffic monitoring Thank you very much for you attention! Questions?
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