FULL PRODUCT VERSION :
ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]
Windows Server 2008
A DESCRIPTION OF THE PROBLEM :
InetAddress.writeObject performs flush() on object output stream.
That spoils TCP throughput when the output stream is based on a socket channel of a TCP connection, since the SYN ACK delay of 2ms of Windows will be invoked when a packet is smaller than the MTU and the next packet is about to be sent.
This bug can be reproduced always.
CUSTOMER SUBMITTED WORKAROUND :
Go to Java 7 update 15. Or insert a filtering output stream ignoring the flush().