Delay in forwarding packet from hostOs to GuestOs in kvm virtual machine

I see delay in forwarding packets when some packet is sent to the guest Os from a different machine.After some time ,when the proprietory client server protocol is going around with the client sending burst of packets to the guest Os (which is running under Kvm),the packets are not dispactched to the GuestOs until the client program is closed.Could anyone please point out any solution in this case in order to eradicate this issue?