[Winpcap-users] How does windows see that the NIC has received data?

[Ramiro Polla]

I was wondering... Is it absolutely necessary for winpcap to keep checking 
the status of the NIC to see if there is any data?
Doesn't the NIC call some interrupt when it receives data. And that 
interrupt could be used to call the callback function.

If it really is absolutely necessary to constantly check the NIC, how does 
windows do it, and couldn't a function be made to call the callback function 
at every packet received? (without the user having to ask every time).

I know nothing about the driver, so I'm just wondering here...