Client identification from bro logs

Hi all,

         It is well known that a client may be behind NAT or using DHCP, so identifying
an individual client solely from the IP address is unreliable. To track a client's behavior
from Bro logs, it is therefore important to separate the clients behind NAT or using DHCP.
Some passive methods for client identification were presented long ago, such as, or

         The features leveraged by the above two papers, IP identifier and TCP timestamp
option, are unavailable from default Bro logs. I would like to know whether the existing
Bro design has a solution to this issue. Many thanks.