Patent ID: 8656170
Filing Date: 2014-02-18
Classification: H04L

Abstract:
1. A method comprising: at a first device that is to enter into a secure communication session with a second device, sending timestamp information and time window size information in a control message to the second device during a first exchange of a first set of control messages between the first device and the second device, the time window size information defining a time window to be used by the second device to test for freshness of a control message received at the second device from the first device during a second exchange of a second set of control messages and the timestamp information representing a time of departure of the control message from the first device with respect to a timing reference of the first device, wherein messages exchanged during the first exchange and during the second exchange comprise messages that are part of a same control plane exchange session between the first device and the second device; and at the first device, receiving timestamp information and time window size information from the second device in a control message during the first exchange from the second device, the time window size information received from the second device defining a time window to be used by the first device to test for freshness of a control message received at the first device from the second device during the second exchange of the second set of control messages, and the timestamp information contained in the control message received at the first device representing a time of departure of the control message from the second device with respect to a timing reference of the second device, wherein the first exchange of the first set of control messages corresponds to Phase