To determine the device name

Use SMIT (System Management Interface Tool):

From SMIT's main menu choose: Devices / CD ROM Drive / List all defined CD ROM drives

cd0 Defined 00-00-0S-5,0 Other SCSI CD-ROM Drive
  

From the shell prompt:

root@aixserver# lsdev -C -c cdrom
cd0 Defined 00-00-0S-50 Other SCSI CD-ROM Drive