The max latency value of queue. The Max Latency value can be 0 and from 16 to 4080, 0 means 'disable'. If packets in a certain queue are sent with over-max-latency, the packet of next queue will be serviced. In this scheme, the latency means a inter-packet-gap value. If max latency value is set 0 (disable), latency is not a factor of scheduling any more.