Java EE (Java Enterprise Edition) General Discussion

Hi ,
I working on Websphere Application Server 5 in Redhat linux 7.3 environment. I am using the junit perf to create 256 concurrent users. All users (through httpclient) are making the request from remote client to server.
While running this, I am getting the following error.

java.net.ConnectException: Operation timed out: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:345)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:157)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:144)
at java.net.Socket.<init>(Socket.java:294)
at java.net.Socket.<init>(Socket.java:121)
at org.apache.commons.httpclient.protocol.DefaultProtocolSocketFactory.createSocket(DefaultProtocolSocketFactory.java:118)
at org.apache.commons.httpclient.HttpConnection.open(HttpConnection.java:683)
at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:662)
at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:529)
at com.fitec.a2.utc.rfs.rfsperformance.RFSPerformanceTest.rfsTest(RFSPerformanceTest.java:63)
at com.fitec.a2.utc.rfs.rfsperformance.TestPerformance.testPerformance(TestPerformance.java:64)
at java.lang.reflect.Method.invoke(Native Method)
at junit.framework.TestCase.runTest(TestCase.java:154)
at junit.framework.TestCase.runBare(TestCase.java:127)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:118)
at junit.extensions.TestDecorator.basicRun(TestDecorator.java:22)
at junit.extensions.TestDecorator.run(TestDecorator.java:28)
at junit.extensions.RepeatedTest.run(RepeatedTest.java:25)
at junit.extensions.TestDecorator.basicRun(TestDecorator.java:22)
at junit.extensions.TestDecorator.run(TestDecorator.java:28)
at com.clarkware.junitperf.TimedTest.runUntilTestCompletion(Unknown Source)
at com.clarkware.junitperf.TimedTest.run(Unknown Source)
at com.clarkware.junitperf.ThreadedTest$TestRunner.run(Unknown Source)
at java.lang.Thread.run(Thread.java:512)

Can anybody help me, I am getting the above error for only 42 users out of 256. For rest of the users i.e. for 214 it is working fine. I need your help .

Thanks,
Likhesh