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Trajectory Sampling
Direct traffic observationTraffic measurement is a critical component for the control and engineering
of communication networks. Traffic measurement should make it possible
to obtain the spatial flow of traffic through the domain, i.e., the paths
followed by packets between any ingress and egress point of the domain.
Most resource allocation and capacity planning tasks can benefit from such
information. Also, traffic measurements should be obtained without a routing
model and without knowledge of network state. This allows the traffic measurement
process to be resilient to network failures and state uncertainty.
Hash-based Packet SamplingWe have proposed a method that allows the direct inference of traffic flows
through a domain by observing the trajectories of a subset of all packets
traversing the network. The key advantages are that (i) it does not
rely on routing state, (ii) its implementation cost is small, and (iii)
the measurement reporting traffic is modest and can be controlled precisely.
The idea of the method is to sample packets based on a hash function computed
over the packet content. Using the same hash function will yield the same
sample set of packets in the entire domain, and enables us to reconstruct
packet trajectories.
Trajectory EngineTrajectory Engine is a prototype system to collect trajectory samples sent
by network routers, and to store them after appropriate preprocessing.
It provides a querying and visualization tool to aid in traffic engineering
and troubleshooting tasks. The engine uses Daytona
as its database, and reuses and extends NetScope to provide query and display
functions through a GUI.
Papers and TalksRelated WorkContacts |
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