how i can send voice from PC to osmocom-bb, and recv traffic voice from osmocom-bb to PC

hello everybody I want to use LCR send voice from PC to osmocom-bb, and recv traffic voice from osmocom-bb to PC. So at osmocom-bb/src/host/layer23/src/mobile/gsm48_rr.c int gsm48_rr_init(struct osmocom_ms *ms) I change