Admission controller for network access

Abstract

The present invention discloses a network access admission controller and the method used to determine its schedulability. The basic principle involves determining, for all the connections to be checked, if there is any time slot, among all the time slots within a cycle, that will satisfy the scheduling property without the possible misjudgment of schedulability found in the conventional technology. The inventive method of determining schedulability makes its judgment based on packets issued by all the connections and on each of these connections individually. In particular, a determination is made regarding whether there is a particular time slot, among all the time slots, corresponding to the cycle of connection under evaluation, such that all the time slots prior to it are capable of processing the previously issued packets from the connections having higher priority than this particular time slot. When the connections all have a time slot that satisfies the above conditions, a connection is determined to be schedulable. However, when any of the connections fail to have a time slot that satisfies the above conditions, a connection is determined not to be schedulable.