Question on ethernet controller

Hi all,
1) Iam working on  Philips LPC 2292 controller board, Ethernet
controller is Rtl8019 and Iam testing Rtl8019 driver on linux 2.6
Kernel.I have few Doubts.

2) If at all if a single packet comes and sits in Rx Buffer. Whether
my ethernet controller immediately raises an Interrupt or it wait for
Few seconds or milliseconds for another packets to sit in Rx Buffer
before it raises an Interrupt.

3) If at all If ISR is Executing and if Before copying a packet from
Rx Buffer to local Buffer, if few packet comes to Eth controller,
will  respective packets sits in Rx Buffer or packets are Denied by
Ethernet controller.

Thanks in advance,
Bab