(A) RSVP is used to transmit signaling of QoS requests, notifying the router of QoS requirements of the application.
(B) It provides guaranteed bandwidth and delay to meet requirements of the application.
(C) In this model, the network maintains the status of each flow (IP addresses and port numbers of source and destination ends), and based on this state packets are classified, policed, queued, and scheduled, meeting application requirements.
(D) It can provide a load control service, to ensure that even in the case of network overload, can provide services similar to the network which is not overloaded, that is, in the case of network congestion, this model ensures that packets of some applications can be processed with the low delay.