Patent ID: 9736064
Date: 2017-08-15
CPC Classifications: H04L

Claim:
1. A method for finding a packet's routing path in a network, comprising: intercepting control messages sent by a controller to one or more switches in a software defined network (SDN); emulating a state of the SDN at a requested time; and identifying one or more possible routing paths through the emulated SDN by replaying the intercepted control messages to one or more emulated switches in the emulated SDN, wherein said one or more possible routing paths correspond to a requested packet injected into the SDN at the requested time; and determining a starting time T where E RTT is the mean RTT, σ RTT is the variance on the RTT, T 0 is the input timestamp, and k is the Z-value in the statistical confidence interval, and otherwise, where T x is the time stamp of the earliest control message matching the packet and violating the above condition; and wherein identifying one or more possible routing paths comprises reconstructing flow table states of the one or more emulated switches based on the intercepted control messages and round trip time (RTT) information.