Patent ID: 8918502

Claim:
A method for determining the state of an entire network, including state of applications and infrastructure; said method comprising the steps: receiving network control messages in a network; passing normal network control messages through FlowSense, a control plane middleware, and constructing from said network control messages an application level connectivity graph to infer network delay between any two communicating server in the network and estimating an application response time of a given server in the network, said FlowSense including a network utilization procedure for computing the utilization of each link in the network derived from using captured messages triggered by switches when flow entries expire; and providing state of the network for enabling intelligent detection and diagnosis of infrastructure and application performance, responsive to said passing step; wherein said FlowSense comprises a server delay SD estimation procedure for estimating a server's application level response time, said SD estimation procedure including a request/response classification whose goal it is to build a metric c that measures the correlation between a pair of request and response messages, said metric c falling into a range [0,1], in which value 0 suggests an uncorrelated message pair and value 1 indicates exact correspondence; wherein said request/response classification cab alternatively be constructed by leveraging existing protocol specific packet fingerprinting techniques or utilize machine learning based statistical approaches.