SQL & PL/SQL

We create a external table like this:

SQL> ed
Wrote file afiedt.buf

  1  Create table EXT_SUBSCRIPTION_ext2 (f1   VARCHAR2(20),
  2                                                        f2      VARCHAR2(30)
  3                                                        )
  4                      organization external
  5                      (
  6                          TYPE ORACLE_LOADER
  7                          DEFAULT DIRECTORY WEBUTIL_EXTERNAL_DIR
  8                          ACCESS PARAMETERS
  9                      (
 10                          records delimited by newline
 11                          fields TERMINATED BY ','
 12                      )
 13                          LOCATION('abcdefghi.txt')
 14                      )
 15                      parallel
 16*                     REJECT LIMIT UNLIMITED
 17  /

Table created.

The directory is mapped to a directory in another machine in the network. i.e. not the DB machine.

SQL> L
  1* SELECT * FROM dba_directories WHERE DIRECTORY_NAME = 'WEBUTIL_EXTERNAL_DIR'
SQL> /

OWNER                          DIRECTORY_NAME                 DIRECTORY_PATH
------------------------------ ------------------------------ --------------------------------------
SYS                            WEBUTIL_EXTERNAL_DIR           \\192.168.10.53\Users\webutiltest\Files

When we run it we get this error:

SQL> SELECT * FROM  EXT_SUBSCRIPTION_ext2 ;
SELECT * FROM  EXT_SUBSCRIPTION_ext2
*
ERROR at line 1:
ORA-29913: error in executing ODCIEXTTABLEOPEN callout
ORA-29400: data cartridge error
error opening file \\192.168.10.53\Users\webutiltest\Files\EXT_SUBSCRIPTION_EXT2_3348_916.log

If the directory the file is in is in the machine where the DB is, this works fine.

So, my question is, is it a MUST that the file an external table is mapped to, reside in the DB machine itself??