global in and global out

Hi everybody,

I read the manual … unfortunaly I didn’t understand the global in and out very well.

… global-in - represents all the input interfaces in general (INGRESS queue)…
… global-out - represents all the output interfaces in general…

Let’s see:
customers–INTERFACE A (local)======MIK Interface C (Public/Internet)
customers–INTERFACE B (local)======

First : Could I say that INT_A and INT_B are always Global IN and INT_C is always Global OUT, regardless the actual flow of trafic ?

OR when the customers send flow to internet, INT_A and INT_B are Global IN and INT_C is Global Out ? AND When they receive from internet INT_C is global IN and INT_A and INT_B are global out ?

Note: In the last option, the same trafic into INT_C from internet is the same going out to customer. And the same trafic into INT_A and INT_B going to internet is the same going out to internt in INT_C.

And to complicate: The trafic is going in and out, going trough all interface at the same time !

So, I’m lost. When I up my mind I figure out global in is the same global out !

Please, help , I know I am stupid. I apreciate helping me !

thanks in advance,
gevasio