Systems, methods, and apparatuses are provided that enable streaming of ATM cells between a transmit/receive data processing application and a transmission convergence function. Data to be segmented into an ATM cell is received at a SAR engine, and provided to a transmission convergence function, with the first cells transmitted to the transmission convergence function before the SAR function receives an end-of-packet indication from the optimization engine. Data received at a transmission convergence function is placed in a received packet queue at the SAR function, with packets provided to an application after a start-of-packet indication is received, and before an end-of-packet indication is received, at the SAR function.