Method and apparatus for passing interactive data over a modem link with low latency

Abstract

A method and apparatus for transmission of time critical data over a modem link is disclosed. Time critical data is intercepted by a modem at its host input-output port. The intercepted time critical data is injected directly at the top of the queue of data intended for transmission over the modem link. The injection of time critical data takes place at the input to the modulator in the form of specially identified frames, preferably of short duration. Time critical data is thus sent on a priority basis bypassing error correction circuits or routines, and bypassing data compression. At a receiving modem, time critical data is recognized in the demodulator as specially identified frames or packets. Such time critical data is recovered and immediately sent to the host without passing through the error correction process and without decompression. The present invention removes a significant amount of delay over modem links and substantially contributes to the quality of applications where time critical data must be timely processed, such as in voice over IP applications using modem links.