What would make a JSP page to start a new session even though I had created one before?

Govind Seshadri

A session can time out due to client inactivity. If this happens, and the user resumes activity later on by going to a "session-enabled" JSP page , the servlet-engine will begin a new session. You can control the session timeout period on a per-client basis by using the session.setMaxInactivationInterval(int secs) method. In most engines, the session timeout interval defaults to 30 minutes.