| 摘要 |
A method and apparatus are provided for making admission decisions in a packet switched network, such as a Differentiated Services (DiffServ) Packet Network. According to one aspect of the present invention, admission control decisions are based upon local information. An average premium service bandwidth utilized on an output link of a network device during a predetermined window of time is calculated. A determination regarding whether to accept or reject a request for a premium service flow involving the output link is made based upon the request, a total premium service bandwidth available on the output link, the average premium service bandwidth, and bandwidth request information associated with one or more flows that have been admitted within a predetermined holding time interval. According to another aspect of the present invention, multicast flows are supported. A measure of utilized premium service bandwidth is calculated for each of the output links of a multicast-capable network device. A request for premium service bandwidth for a multicast session is forwarded onto those of the output links specified by a multicast routing protocol which have sufficient premium service bandwidth available to accommodate the request based upon the total premium service bandwidth available on the output link, the measure of utilized premium service bandwidth on the output link, and the request. For each of the output links associated with the multicast session, a link state is maintained. The link state indicates the current state of a state machine that determines the behavior of the multicast-capable network device for the corresponding output link of the multicast session. Multicast packets that are subsequently received are forwarded according to the link states associated with the output links. |
