Network Visualization Introduction Presented by Shahed - PDF document

Network Visualization Introduction Presented by Shahed Introduction Introduction • Basic building blocks – Node – Links (relationship between nodes) – Spatial information – Network data http://zeeb.library.cmu.edu:7850/JoSS/article.html 3 4 Paper List Paper List • Visualizing Network Data • Visualizing Network Data – Richard A. Becker, Stephen G. Eick, Allan R. – Richard A. Becker, Stephen G. Eick, Allan R. Wilks. Wilks. • 3D Geographic Network Displays • 3D Geographic Network Displays – Kenneth C. Cox, Stephen G. Eick, Taosong He. – Kenneth C. Cox, Stephen G. Eick, Taosong He. • CyberNet: A framework for managing • CyberNet: A framework for managing networks using 3D metaphoric worlds networks using 3D metaphoric worlds – P. Abel and P. Gros and D. Loisel and C. Russo – P. Abel and P. Gros and D. Loisel and C. Russo Dos Santos Dos Santos 5 6 1

Goal Traditional Approach • To reduce cluttering of data (traditional) • Visualize the data associated with a network – Aggregation : for large numbers of links or nodes – Understand data, not network themselves • Coping with large data volumes – Averaging : for large numbers of time periods – Hundreds of nodes – Thousands of links – Thresholding : for detecting changes – Data from time periods • Overcome the map clutter problem 7 8 Solution Dataset • SeeNet • Telecommunication traffic – Static Displays • 110 switches in the AT&T network • Link Map • 12,000 links • Node Map • Matrix • Oct. 17, 1989, (San Francisco – Interactive Controls earthquake) • Parameter focusing • FOCUS: • Data filtering – Animation – Traffic flow between switches (nodes) • Smooth zoom 9 10 Static Displays (1/3) • LINK MAP Static Displays – Draw lines connecting nodes – Show values using colors or thickness of line 12 2

Static Displays (LinkMap) Static Displays (LinkMap) Focus on one Node (Oakland ) Include all nodes (10% of links shown) 13 14 Disadvantage Static Displays (2/3) • Disadvantage of Link Map • NODE MAP – Too many links cause map cluttering – Aggregation of information at each node – Use Node Maps !!! – Use Glyphs • Vary Size, shape, color for statistics 15 16 Static Displays (NodeMap) Disadvantage 1) Tall & Thin: Outbound • Disadvantage of Node Maps overload (green) – Detailed Information about particular links lost 2) Short & Fat: Inbound Overload – Solution: (red) • Do away with geography • Try Matrix display 3) Square: Equal load (white) 17 18 3

Matrix Display 19 20 http://funwavs.com/movie/pictures/the-matrix/ Static Displays (3/3) Disadvantage • MATRIX • Disadvantage of Matrix Display – Concentrates on links of a network (like Linkmap) – Information about geography lost – Color of square designates traffic – Does not have problems of geographic • Tries to fix problem with nodes ordered from west coast to east coast along axis displays: • Visual prominence of long lines • Long lines (transcontinental) over plots others 21 22 Parameter Focusing Parameter • Parameters determine network display Focusing • Parameter values (range) control what is displayed – Example: – Glyph size in node maps – Coloring of nodes & links • Dynamic parameter adjustments helpful 24 4

Parameter Focusing Example Parameter classes (Shortened Links) • Statistics • Levels • Geography / topology • Time • Aggregation • Size • Color 25 26 Issues with parameter Direct Manipulation focusing • Automatic animation • Space of parameters large • Manual animation • Combination of parameters to chose • Sound • Displays sensitive to particular • Conditioning (‘and’ operation on parameter values parameters) • Identification (display tool tip of node) • SOLUTION • Zoom – Allow Direct manipulation of parameters • Birds-eye view 27 28 Other applications (non Example (zoom in Link Map) geographic) • Left: All line segments intersecting the display • Middle: any line segments with at least one endpoint in the display • Right: only lines that both begin and end inside the display CICNET EMAIL Communication 29 30 5

Critique Paper List • The Good • The Evil • Visualizing Network Data – Clear graphs with – Self evaluation (no – Richard A. Becker, Stephen G. Eick, Allan R. interpretation user studies) Wilks. – Presented motivation – Redundant • 3D Geographic Network Displays and challenge information – Kenneth C. Cox, Stephen G. Eick, Taosong He. papers (parameters and – Tested on different • CyberNet: A framework for managing direct manipulation) data sets networks using 3D metaphoric worlds – Provides – P. Abel and P. Gros and D. Loisel and C. Russo implementation Dos Santos details (C++ & Vz) 31 32 Introduction Global Network 1/2 • Presents “ SeeNet 3D” – 5 network views • 2 views are geography related • 3 views concentrate on portion of a large network • SeeNet3D follow-up of – SeeNet – NicheWorks Global packet count in 2 hour period Tall red glyphs have more traffic 33 34 Global Network (2/2) Disadvantage - Arc Maps • Only Front side of map viewable • Draw arcs on flat 2D map in 3D space – Occludes arc ends • Solution – 2D map can be oriented as desired – Make globe partially translucent (does not work with too many arcs) – Eliminates line crossing to a certain extent (vary arc height) – Allow user to route arcs (through globe if needed) – Filtering 35 36 6

Arc Map without Arc Map with parameterization parameterization of height of arc height Add translucency of arc &, coloring and size glyphs of countries 37 38 Drill Down network views Spokes on a wheel • Three types of views: -Works for 50 to 100 nodes -Does not make efficient – Spokes on a wheel use of screen space : All spokes of equal length – Helix -Better approach (Helix) – Pin Cushion Traffic to/from US to other countries 39 40 Helix Pin Cushion -Motivated by helix -When Viewed from above, display Helix view becomes spoke view -Position uniformly around sphere (anchor -Use rotation of helix to node) bring occluded nodes into view - Number of circles and number of nodes per -Preferred approach by circle chosen such that authors over others (more angle between circles ordered) and between nodes in a circle same 41 42 7

Critique Paper List • The Good • The Evil • Visualizing Network Data – Shows more in less – No user studies (as – Richard A. Becker, Stephen G. Eick, Allan R. space (5 vs 3) usual) Wilks. – Provides – Some displays have • 3D Geographic Network Displays implementation limited information – Kenneth C. Cox, Stephen G. Eick, Taosong He. details – Does not give • CyberNet: A framework for managing scalability constraints networks using 3D metaphoric worlds for most – P. Abel and P. Gros and D. Loisel and C. Russo Dos Santos 43 44 Geographic administration Introduction building metaphor -For physical link problem detection • Network administration in 3D • Provides 5 metaphors -Building ( a container for network • Dynamically builds & updates 3D world devices) • Captures information -Object location is relative to position in – Topology, Connectivity, Routing, Mailing, actual world NFS -User allowed to • Each 3D tool solves specific problems – chose destination chose metaphor that best suites a task (automated paths) -Filtering 45 46 Distributed system admin Topology administration cone-tree metaphor city metaphor - Maps Client/server Red: switches (Mail, DBMS, NFS) Blue: Hubs Leaves: Computers -Separate Client & server view Size of cone depends on bandwidth flow in -Metaphors: hub Town : sub network District : Computer Building : Disk resource On server: -Each client a floor -Each window a 47 48 File Handle 8

Computer admin tool Network traffic characterization solar system metaphor landscape metaphor Metaphors: Stars Planets satellites To: Computers Users Processes 49 50 More on CyberNet Critique • Users can toggle between various 3D • The Good • The Evil structures – design architecture – Some concepts explained unclear (city • Technical Stages metaphor) – Implementation – Collecting Layer (subscribe/notify, agents) language for each – No user studies stage (VRML, corba, • Mentions users found – Structuring Layer (build service model tree) Java, perl) metaphors helpful – Visualization Layer (generate 3D form) – No scalability – Screen Shots helpful discussion – Dead Site !! 51 52 ? QUESTIONS ? 9