This is important since if the network is congested, packets get dropped and many sessions timeout. This in turn involves hosts retransmitting data, further congesting the network. By controlling the rate at which data enters the network, administrators can ensure that packets reach their destination and do not need retransmitting. This process not only smoothes out the traffic flow but in conjunction with CBQ provides precise rate control. Packet Size Optimization Controls the size of TCP packets that enter the network.
Large packets take some time being transmitted by routers.
Once the transmission has begun it doesn't get preempted, therefore is a small time sensitive packet like a voice packet arrives, it has to wait longer at the router. By making the size of TCP packets smaller latency sensitive traffic like VoIP and Citrix are protected and this also gives administrators more control over delay and jitter for these applications. All current router based QoS standards are supported such as IP precedence and all Diffserv code points. Fair Bandwidth Allocation by Connection Using class based queuing, when priorities and bandwidth settings are specified for particular traffic classes, there is no control for how that bandwidth is used. This means that one individual use can take up the entire bandwidth allocated and leave others starved.