You are probably getting a HTTP timeout. It is not good practice to keep a page connection open so long as it has a very negative impact on scalability. For large loads, this acts like a denial of service on the server, and will probably be an unusable solution for the user. You can look at the timeout setting for the web application server (servlet server) you are using to work out the timeout setting for the listener/connector. Look at the Apache Tomcat or Jetty websites, depending on your configuration to find out more about their timeout controls. You may also get a timeout on the connection from the connection pool as well.
YMMV but I would recommend you reconsider the practicalities of this solution.
thanks a lot