Patent ID: 7944814
Filing Date: 2011-05-17
Classification: H04L

Abstract:
1. A method of communication, comprising: maintaining primary and secondary network media devices at a substantially similar encryption state, wherein the secondary network media device is a redundant network media device, wherein the maintaining comprises copying reception and transmission switchover parameters from the primary network media device to the redundant network media device, wherein the maintaining comprises utilizing a packet sequence number that is calculated based on an initial randomly-selected sequence number, wherein the maintaining comprises: at pre-defined time intervals, updating by the primary network media device values of the switchover parameters stored in a storage array residing within the secondary network media device; wherein the method comprises: switching from the primary network media device to the secondary network media device by (a) estimating by the secondary network media device current values of transmission switchover parameters, and (b) calculating by the secondary network media device current values of reception switchover parameters, wherein maintaining comprises: based on last-known values of the switchover parameters, estimating current values of said transmission switchover parameters; wherein the estimating comprises estimating of: a transmitted Real-Time Transport Protocol (RTP) time stamp, a transmitted RTP sequence number, a transmitted Rollover Counter (ROC), and a transmitted Real-Time Control Protocol (RTCP) index; wherein the estimating comprises an estimation for re-synchronization by a security protocol based on the estimated current values of said switchover parameters using a mechanism corresponding to recovery from network packet loss.