Patent ID: 9043472
Filing Date: 2015-05-26
Classification: H04L

Abstract:
1. A method comprising: generating, at an intermediate node, a first keep-alive probe signal designated for a first end terminal in an end-to-end communication path and a second keep-alive probe signal designated for a second end terminal in the end-to-end communication path, the intermediate node residing at a point in the end-to-end communication path between the first end terminal and the second end terminal; during a communication session between the first end terminal and the second end terminal, transmitting, from the intermediate node, the first keep-alive probe signal to the first end terminal and the second keep-alive probe signal to the second end terminal; determining that a complete response to the first keep-alive probe signal and the second keep-alive probe signal has not been received by the intermediate node from the first end terminal and the second end terminal within a predetermined period of time after the first keep-alive probe signal and the second keep-alive probe signal were transmitted to the first end terminal and the second end terminal, wherein determining that the complete response has not been received comprises comparing a first TCP sequence number associated with one of the first end terminal or the second end terminal with a second TCP sequence number associated with new data transmitted from one of the first end terminal or the second end terminal; and in response to a determination that the complete response has not been received by the intermediate node updating a status of the communication session to indicate an invalid state of the communication session.