服务器的listener.ora：

# listener.ora Network Configuration File: /ORACLE/u01/app/oracle/network/admin/listener.ora
# Generated by Oracle configuration tools.

SID_LIST_LISTENER =
? (SID_LIST =
??? (SID_DESC =
#????? (SID_NAME = PLSExtProc)
????? (SID_NAME = sim)
????? (ORACLE_HOME = /ORACLE/u01/app/oracle)
????? (PROGRAM = extproc)
??? )
? )

LISTENER =
? (DESCRIPTION_LIST =
??? (DESCRIPTION =
????? (ADDRESS_LIST =
#??????? (ADDRESS = (PROTOCOL = TCP)(HOST = localhost.localdomain)(PORT = 1521))
??????? (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.23)(PORT = 1521))
????? )
??? )
? )

?

?

客户端的tnsnames.ora：

# tnsnames.ora Network Configuration File: D:\Oracle\product\10.1.0\Client_1\NETWORK\ADMIN\tnsnames.ora
# Generated by Oracle configuration tools.

SIM =
? (DESCRIPTION =
??? (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.23)(PORT = 1521))
??? (CONNECT_DATA =
????? (SERVER = DEDICATED)
????? (SERVICE_NAME = sim)
????? (SID = sim)
??? )
? )

?

?

?

?

问题解决了，
是要注释掉listener.ora中的(PROGRAM = extproc)
但我不知道是为什么？
遇到ORA-28547的人不少，可是原因却各不一样：
http://forums.oracle.com/forums/message.jspa?messageID=693607