[Freeswitch-users] Question about fifo and SIP 200 OK response

Hi, I observe that, on receiving an incoming call and placing it into a fifo, FS sends back a SIP 200 OK response to the caller. Is it feasible for me to avoid this, and rather send back SIP 180? I tried adding ring_ready application before fifo in, but the SIP 180 is succeeded by SIP 200.