Crovella

60 %
40 %
Information about Crovella
Product-Training-Manuals

Published on October 5, 2007

Author: Mertice

Source: authorstream.com

On The Marginal Utility of Network Topology Measurements:  On The Marginal Utility of Network Topology Measurements Mark Crovella with Paul Barford, Azer Bestavros, and John Byers Discovering Internet Topology:  Discovering Internet Topology Typical goal: discover the router-level Internet graph (nodes and edges) Typical approach: merge a collection of node and edge lists Using traceroute:  Using traceroute Traceroute reports the IP path from A to B Ie, how IP paths are overlaid on the router graph Traceroute studies:  Traceroute studies Yield overlays of projections from S’s to D’s Sources: active, expensive Destinations: passive, cheap S S D D D D D Motivating Questions:  Motivating Questions How should we use traceroute and what can it discover? Physical topology (nodes, links)? IP routing topology? What’s a good way to organize a collection-of-traceroutes study? Many sources? Many destinations? How much is enough? What might we expect?:  What might we expect? Clique: each new Source (Dest) discovers a new path Star: each new Source (Dest) discovers only a small neighborhood Marginal Utility sheds light on this distinction D D D D D D D D D D Clique Star Skitter to the Rescue:  Skitter to the Rescue Two datasets from CAIDA Small dataset: May 2000 8 sources, 1277 destinations, 20K paths Sources in: New Zealand, Japan, Singapore, San Jose (2), Ottawa, London, Washington All sources traced to all destinations Large dataset: October 2000, 30 times bigger 12 sources, 313709 destinations, 600K paths No destination common to all sources, or vice versa Interface Disambiguation:  Interface Disambiguation Traceroutes report only on interfaces used Routers often have multiple interfaces But merging traceroutes requires matching routers Solution: probe each interface from some site X Routers are supposed to respond on the interface used for routing to X Results in set of (probe interface, response interface) pairs Each connected component is taken to be a router Classifying Nodes:  Classifying Nodes Core, border, stub, leaf Solely from traceroute information Leaf Border Core Stub Classification depends on msmts:  Classification depends on msmts Core Stub Border Limitations:  Limitations Interface disambiguation 13% of interfaces never responded Node classification Identifying a border node requires two paths to it Size Datasets may not be representative Unknown coverage of true network Diminishing returns may not signify good coverage Diminishing Returns: Nodes:  Diminishing Returns: Nodes Diminishing Returns: Links:  Diminishing Returns: Links Large Dataset: Interfaces:  Large Dataset: Interfaces Large Dataset: Links:  Large Dataset: Links Diminishing returns by Classification:  Diminishing returns by Classification Core Stub Border What Does This Suggest?:  What Does This Suggest? D D D D D D S S Adding Destinations: Nodes:  Adding Destinations: Nodes Slope is about 3 Adding Destinations: Links:  Adding Destinations: Links Slope is about 4 Add Sources or Destinations?:  Add Sources or Destinations? Isolines represent constant node discovery, varying S’s or D’s Node Degree Distribution:  Node Degree Distribution 8 Sources 1 Source Node Degree Distribution: Tail:  Node Degree Distribution: Tail 1 Source 8 Sources Degree distribution convergence: RMSE:  Degree distribution convergence: RMSE Related Work:  Related Work Pansiot & Grad ’98 First multi-traceroute study Many similarities, incl. interface disambiguation Chuang & Sirbu ’98 Phillips, Shenker & Tangmunarunkit ’99 single-source case, found sublinear growth of multicast tree with added destinations Govindan & Tangmunarunkit ’00 Extensive node discovery, overcoming limitations of traceroute Broido & Claffy ’01 Larger datasets; more detailed look at graph structure Conclusions:  Conclusions To discover all physical nodes, traceroute is inefficient Diminishing returns: many S’s and D’s needed Trading off S’s and D’s Adding destinations seems more cost-effective To discover how “typical” routes pass through network, traceroute is informative Routing core and feeders Much of routing core is visible from few S’s (given enough D’s)

Add a comment

Related presentations

Related pages

Crovella, Mark - Computer Science | Boston University

Contact. Department of Computer Science Boston University. 140E Math & Computer Science 111 Cummington Mall Boston, MA 02215 (617) 353-8919 crovella@cs.bu.edu
Read more

feliciano crovella - AbeBooks

Incisional Hernia (Updates in Surgery) von Feliciano Crovella, Giovanni Bartone, Landino Fei und eine große Auswahl von ähnlichen neuen, gebrauchten und ...
Read more

Albumbesprechung Beppe Crovella - What's Rattlin' On The ...

Albumbesprechung Beppe Crovella - What's Rattlin' On The Moon? . CD-Kritiken, Plattenkritiken und Infos zur Rock- und Popmusik
Read more

Suchergebnis auf Amazon.de für: Crovella: Musik-Downloads

Online-Shopping mit großer Auswahl im Musik-Downloads Shop.
Read more

Mark Crovella - DBLP

Mark Crovella - DBLP
Read more

Verteilung des Namens "Crovella" in Deutschland - verwandt.de

Verteilung des Namens Crovella: Woher kommt der Name Crovella ? Unser Kartenmaterial enthält die Namensverteilung zu über einer Millionen Namen
Read more

Ben Crovella | LinkedIn

View Ben Crovella’s professional profile on LinkedIn. LinkedIn is the world's largest business network, helping professionals like Ben Crovella discover ...
Read more

Beppe Crovella - Official Web Site

Beppe Crovella - Official Web Site
Read more

Paola miralles Crovella - telemarketing, resepcionista ...

Ähnliche XING-Profile wie das von Paola miralles Crovella. Sara Parras Eliche Publicidad y Relaciones Públicas Jaén
Read more

Top 25 Crovella profiles | LinkedIn

View the profiles of professionals named Crovella on LinkedIn. There are 163 professionals named Crovella, who use LinkedIn to exchange information, ideas ...
Read more