my %INPUT_DATA = (
  'DEVICE1_NAME' => {
                      '1/1/5/40' => {
                                        'ACTUAL' => {
                                            'SVC' => '239',
                                          'SPTM' => '112',
                                        },
                                        'NEW' => {
                                            'SVC' => '239',
                                          'SPTM' => '183',
                                        },
                                      },
                    }, ...

# Now, you can use:
#....set $device_name
#....
foreach my $current_port ( sort keys %{$INPUT_DATA{$device_name}} ) {
    my @CURRENT_PORT_STATUS = print( "show xdsl operational\-data line $current_port detail");
}