RpcDispatcher test fails when working with large values

The two tests:

• testLargeReturnValue
• testLargeReturnValueUnicastCall
  make RPC calls with values which are increasingly large.

The values used are in this range:

SIZES={10000, 20000, 40000, 80000, 100000, 200000, 400000, 800000,1000000, 2000000, 5000000}

The tests have been see to fail with the values 1000000, 2000000 and 5000000, always with the same error in each case.

In the case of testLargeReturnValue, the test fails because one of the returned values from the RPC is null.

In the case of testLargeReturnValueUnicastCall, the test fails due to a timeout while sending the RPC.