Oracle Database Discussions

I have created the Oracle datasource in WSAD IE 5.1

datasource : mydb
database name: mydb
jndi name : jdbc/mydb
servername : myserver.mydomain.com
port no : 1522
URL : jdbc:oracle:thin:@myserver.mydomain.com:1522:mydb

Now when I try to run the application on Websphere 5.1 Integration Test Environment, I get the following exception trace:

J2CA0122I: Resource reference jdbc/mydb could not be located, so default values of the following are used: [Resource-ref settings]
....

Begin backtrace for nested exception
java.sql.SQLException: Io exception: The Network Adapter could not establish the connection

Can anybody tell me,what is the problem and how I can solve that? The oracle server is some other machine. I have the client installed on my machine. Do I have to do any configuration on my machine?

Thanks in advance
ratan