Patent ID: 8031628

Claim:
A computer implemented method to probe a network, comprising: a. generating a set of probing pairs from a network topology for unicast network delay tomography; b. probing the network using monitoring hosts in the network; c. determining network performance from the probing results; and d. determining an observed information matrix (OIM) J, wherein the OIM comprises determining J l ′ , d ′ , l ″ , d ″ ⁡ ( o r 1 , o r 2 ) = AL - D l ′ , d ′ ⁢ D l ″ , d ″ L 2 and J ⁡ ( o r 1 , o r 2 ) = ( J l ′ , d ′ , l ″ , d ″ ⁡ ( o r 1 , o r 2 ) ) as a matrix defining contributions to the OIM made by a pair of observations (o r 1 , o r 2 ), where (l′, d′) comprises a row index and (l″, d″) comprises a column index, L is a likelihood function for a single pair of observations (o r 1 , o r 2 ) where the determination of D l*,d* , A comes from: P ( D l* =d*,o r 1 ,o r 2 )= D l*,d* θ l*,d* and P ( D l′ =d′,D l″ =d″,o r 1 ,o r 2 )= Aθ l′,d′ θ l″,d″ for l′≠l″.