to really get the right configuration we would need to know more about the application.
One way you can do this is with source IP Sticky. By default it does not timeout, but when the very large sticky table gets full the CSS will overwrite the entry that has been idle the longest. I have worked with many customers who never fill up the sticky tables.
If this is HTTP based you might be better off using cookies. There are 2 methods to utilize cookie sticky on the CSS: 1) you can have the CSS insert the cookie 2) you can stick based on cookies the server sets.
If you use cookies it maybe possible to attain the "never timeout" criteria as long as the client cookie doesnt expire (and the client doesn't clear cookies)
But, as I stated above, to really help here we would need more details on the nature of your application and what you really mean by "never timeout". (can we timeout after one day of idle?)
-Steve
