The Allot queuing mechanism is built using the hierarchical approach, thus subclasses of traffic could be independently prioritized within the class, while traffic classes maintain priority among them. These queues are combined with bandwidth guarantee and limitation mechanisms that provide preferred treatment to flows with traffic guarantee policies. These bandwidth guarantee policies are implemented using combination of leaky bucket and token bucket techniques. These techniques provide precise bandwidth allocation control as well smoothing and delay guarantees. Allot products use these mechanisms to support DiffServ definition, not only managing the local bandwidth, but marking and remarking IP datagrams according to their conformance to the traffic policy profiles.
Traffic is classified according to policy and then assigned to various priority queues.
Although this technique is very accurate for outgoing traffic, it is not effective for control of inbound WAN traffic. Queuing is a localized solution that only takes into account the state of the network at the point of the prioritizing system. If traffic suddenly becomes congested, packets will begin to accumulate in the various queues. In summary, bursty data traffic, caused by delays throughout the network, are not easily dealt with using local queues. In addition, this queuing system focuses primarily on outbound traffic.