After setting up alias in SQLNet to connect to the remote oracle8.0.5 database on WinNT .

I did TNSPING in client , The result is OK but it took very long time to get the reply . Around 30 seconds .

While I am using SQL+ or some other tools to connect system/manager@ , the connection is simply hung ,
no error msg report and it seems it's trying very hard to connect . meanwhile , I go to server and check the listener.log , I can found actually there is a msg shows that client is connectting .

So what's the cause ?

I am using Personal Oracle7 in the client .

BTW , I did connection successfully to some other database which is oracle7.3 .