A method and a wireless communication device (104) capable of flow controlling data to be sent from a TE2 device (102) over a Rm interface when PPP renegotiation occurs over a Um interface. Flow control (S320) is asserted by the MT2 device (104) by means of manipulating electrical signaling of a physical interface between the MT2 device (104) and the TE2 device (102). A second embodiment provides a method and a wireless communication device (104) for buffering (S420) data on the MT2 device when the PPP renegotiation of the Um interface occurs. In a third embodiment, data is buffered when the PPP renegotiation of the Um interface occurs. When an amount of free buffer space is less than a predetermined threshold (S540), flow control is asserted (S550) to the TE2 device.