What method at the application layer can be used to reduce the effects of
jitter?
http://www.google.com/search?q=packet+jitter&oq=packet+jitter&aqs=chrome..69i57j0l5.2987j0j7&sourceid=chrome&es_sm=119&ie=UTF-8
Read everything you can in these search results; you should find answers to your questions somewhere in here.
And here's another place for search for this very technical information:
http://www.webopedia.com/