Connecting modem to C7206

Hi all,
I’m trying to connect Cisco 7206 router to modem to accept dial-in connections. The modem uses the old serial cable (RS232 25 pin). I used the RS232 25 pin – 9 pin + console cable to plug it into the AUX port. However, the modem still does not pick up the call. Is this the right way? if not, can anyone tell me if there is any ready-made cable in the market or the cable pinouts if I were to custom-made this? Thanks.