Patent ID: 7046693
Filing Date: 2006-05-16
Classification: H04L

Abstract:
1. A method of determining availability in a bi-directional segment connecting two terminating devices in a communications network, the two terminating devices periodically transmitting and receiving data packets, the periodically transmitted data packets being received according to an expected arrival format said method comprising: monitoring a first direction of the segment over a monitoring time interval to detect a change in arrival format of the periodically transmitted data packets from the expected arrival format; monitoring the first direction to detect a notification message indicating a change in arrival format of the periodically transmitted data packets from the expected arrival format for a second direction of the segment; detecting an unavailable time interval between the detected change in arrival format from the expected arrival format to a detected change in arrival format of data packets back to the expected arrival format for at least one of the first direction and the second direction of the segment; modifying the unavailable time interval to remove a predetermined interval representing a latency between the change in arrival format and detection of the change in arrival format; and determining an available time interval for the bi-directional segment based on a difference between said monitoring time interval and said modified unavailable time interval.