Can not connect to informix unsing dg4ifmx

Hi expert

I can not connect to informix unsing dg4ifmx

i receive the output.

SQL> select * from dual@ds1;
select * from dual@ds1
                   *
ERROR at line 1:
ORA-28545: error diagnosed by Net8 when connecting to an agent
Unable to retrieve text of NETWORK/NCR message 65535
ORA-02063: preceding 2 lines from DS1

initds1.ora

# This is a customized agent init file that contains the HS parameters
# that are needed for the Database Gateway for Informix

#
# HS init parameters
#
HS_FDS_CONNECT_INFO=[XXX.XXX.XXX.XXX]:8001/on_abc1/ds1
HS_FDS_TRACE_LEVEL=OFF
HS_FDS_RECOVERY_ACCOUNT=RECOVER
HS_FDS_RECOVERY_PWD=RECOVER