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Efficient IP-Level Network Topology Capture. Thomas Bourgeau and Timur Friedman LIP6-CNRS and LINCS Laboratories, UPMC Sorbonne Universit´es. Introduction. IP-level internet topology Ark, DIMES, and iPlane 9.1 million /24 IPv4 address prefixes => one or more days Redundancy
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Efficient IP-Level Network Topology Capture Thomas Bourgeau and Timur Friedman LIP6-CNRS and LINCS Laboratories, UPMC Sorbonne Universit´es
Introduction • IP-level internet topology • Ark, DIMES, and iPlane • 9.1 million /24 IPv4 address prefixes => one or more days • Redundancy • Network dynamics
GDT (Generic Distributed Tracing) • Tracing system: A server and a set of agents • Tracing is conducted in a series of rounds • Each round has three phases Dispatch Probing Update
GDT Framework • Dispatch Phase: • Instructions are sent from the server to the agents. • a list of destinations, expected views • Probing Phase: • Agents carry out instructions, recording the results to send back to the server. • Update Phase: • The server collects the results from each agent and updates its database of expected views.
GDT Framework • Query: a partial trace instruction • the existence of edge e • q=(s, d, h, l) • e=(v1, v2) starting :h ending : h+l • Expected view c=(q, e) edge e is not present additional probing
Related work ---Doubletree • Aim : all source-destination paths • Means: partial trace routes • Innovate: (probing) • It divides the destination set into subsets • It divides each round into sub-rounds. • “Stop set” Round Sub-round Stop set Agent
Related work --Gonen and Shavitt • Aim: obtain the entire graph • Means: fewer full trace routes • Innovate: (dispatch) • destination sets for each agent that are subsets.
NTC (Network Topology Capture) • Graph-based perspective • Network topology dynamics • Aim : obtain the entire graph • Means: partial trace routes
NTC (Network Topology Capture) • Dispatch phase: • A set of expected views, a set of destinations • Globally capping the number of queries per edge ɑ • Probing phase: two heuristics • Redundancy Aware Probing • Dynamism aware probing
NTC (Network Topology Capture) • Redundancy Aware Probing • ɑ
NTC (Network Topology Capture) • Dynamism aware probing • fail to yield the expected edge=>routing has changed • ß
Evaluation • Each agent performed one measurement round /hour • Total rounds =1480
Summary • A new approach to distributed network route tracing. • 6% to 24% of the full trace budget • network dynamics