How to generate PAUSE frame

[bill]

Hi, all


I have a 10G NIC card with fiber interface, this NIC is drived by a private os with l2 rxonly forwarding function,
and I want to test this NIC could sent out PAUSE frame. 

  host                       client
+--------+                +------------+
|            |    fiber       |  10G NIC |
|  NIC    |  <===>   |  l2fwd      |
|            |                 |  rxonly     |
+--------+                +------------+

If host send packet faster than client could receive, client 10G NIC should send out PAUSE frame,
and use "ethtool -a eth0" on host to show any PAUSE frame received.

How could I do this without any faster NIC card than 10G?



thanks  

bill