Let us consider a situation when you are using a Web-Proxy on your MikroTik router and you want
to use bandwidth limitation to/from Internet and allow the maximum speed available if the clients
use proxy-data (or do uploads to the router). In this situation you can use global-in and global-out
virtual interfaces. Remember that data from Web-Proxy is sent to clients from Local Process
What do you want to do? assuming you want to allow max speed from cache to the clients, try to search the forums, this question has been answered many times, here you will find an example: http://www.mikrotik.com/docs/ros/2.8/root/queue.content#6.54.7.4 this is for 2.8 but you only have to change the syntax.
Regards…