Patent ID: 6453343
Filing Date: 2002-09-17
Classification: H04L,H04W

Abstract:
A method of persistent cache synchronization for a first communication session and a concurrent second communication session over an external communication link between an application executing on a first computer and an application executing on a second computer located remote from the first computer, the method comprising the steps of:establishing a first cache operatively associated with the first session at the first computer and a corresponding second cache operatively associated with the first session at the second computer; establishing a third cache operatively associated with the second session at the first computer and a corresponding fourth cache operatively associated with the second session at the second computer; transmitting a checkpoint request to the second computer indicating one of the first or the third cache to be used to provide a checkpoint; receiving the checkpoint request at the second computer; copying the second cache responsive to the received checkpoint request if the checkpoint request indicates the first cache to provide a checkpoint cache of the second computer; copying the fourth cache responsive to the received checkpoint request if the checkpoint request indicates the third cache to provide a checkpoint cache of the second computer; associating the checkpoint cache of the second computer with both the first and the second session; transmitting a checkpoint confirmation message to the first computer responsive to said step of copying the second cache and said step of copying the fourth cache; receiving the checkpoint confirmation message at the first computer; creating a checkpoint cache of the first computer as a copy of the indicated one of the first or the third cache responsive to the received checkpoint confirmation message; associating the checkpoint cache of the first computer with both the first session and the second session to provide a checkpoint; and then repeating said steps of transmitting a checkpoint request, receiving the checkpoint request, copying the second cache, copying the fourth cache, associating the checkpoint cache of the second computer, transmitting a checkpoint confirmation message, receiving the checkpoint confirmation message, creating, and associating the checkpoint cache of the first computer to provide a new checkpoint.