i would like some optimisation tips about joomla performance i made use of memcache however i dont now using proxy and reverse proxy () with joomla help Thanks

I suppose that you're speaking about caching reverse proxy.

You're doing so just like every other application: setup your webserver to pay attention on port 81, then set squid on a single machine, allow it to be listen on 80 and toward 81. If you are not hosting for clients, you are able to enable aggresive caching, otherwise you might have difficulties with clients upgrading their content although not seeing the alterations on frontend.