Trajectory sampling for direct traffic observation

Trajectory engine: a backend for trajectory sampling

The management of communication networks increasingly requires detailed knowledge of network usage, acquired by direct measurement. We report on the design and implementation of a backend system for Trajectory Sampling, a method for consistent sampling of packets across a network domain. This Trajectory Engine collects trajectory samples and stores them after appropriate preprocessing. It provi...

Trajectory Sampling: White Paper

TS implements consistent packet sampling. Conceptually, each packet traversing a measurement domain is sampled either on every link traversed, or on no link at all. Some highly compressed information on sampled packets are collected centrally in a collection system, which is then able to reconstruct the trajectory (path) of each sampled packet [5]. This set of sampled packet trajectories provid...

Direct Observation

The term “non–intrusive” is often used to characterise this technique: Users do what they normally do without being disturbed by the observ e r s . One of the advantages of this method is that users can be observed in the e n v i ronment where the system is normally used. This is why dire c t o b s e rvation is said to have high face validity, also re f e rred to as extern a l validity or ecolo...

Trajectory Sampling: White Paper Draft

TS implements consistent packet sampling. Conceptually, each packet traversing a measurement domain is sampled either on every link traversed, or on no link at all. Some highly compressed information on sampled packets are collected centrally in a collection system, which is then able to reconstruct the trajectory (path) of each sampled packet [5]. This set of sampled packet trajectories provid...

Sampling-based Sub-Trajectory Clustering