Method and apparatus for improving the performance of voice over IP (VoIP) speech communications systems which use robust header compression (RoHC) techniques

摘要

A method and apparatus for use in improving the performance of Voice over Internet Protocol (VoIP) communication systems which use Robust Header Compression (RoHC) techniques for reducing communications protocol overhead. Specifically, having recognized that in VoIP applications (unlike, for example, data services applications), severely late packets cannot be used, a “RoHC-Guard” filters out packets that are very late, making it impossible for RoHC to perform the costly and unnecessary re-sync. In accordance with one embodiment of the invention, a RoHC-Guard module, operating as a pre-filter to a RoHC module, saves, rather than merely discards, late packets. Then, if a predetermined number of such packets are consecutively received, they are provided to RoHC module.