how can i capture traffic usage of float ip and router port in ovn?

[alifrd]

i need to calculate traffic usage of my router and the floating ip in ovn base openstack cluster. as you know when you use floating ip or router you have logical port, not Ovs port. that means all nat and snat perform by flow tables. but im not sure how can i get exact amount of traffic used in these logic ports?

in flow entries i can see n_packets, n_bytes but i'm not sure that be the exact amount of traffic. cookie=0xbf388ed1, duration=517695.002s, table=17, n_packets=23667, n_bytes=1867366, idle_age=1552, priority=2002,