3 sec delay in transaction when going via F5

It happens with other client as well..happening irrespective of the client and when i issue request directly from the same to the real server on the customized port...i see no netbios in the pcap.is it like to initiate the client hello, it has to get the netbios name ?

will check pcap viia ace as well .still waiting as the customer isn't available..thanks a lot for your response. Will try creating forwarder as well for the netbios request.