In order to calculate the worst-case link delays in the EDD (Earliest Due Date) connection admission control scheme, a check called the point schedulability check is necessary for each of finite and discrete time instants (checkpoints). In our previous calculation method, high speed calculation is attained by decreasing an upper bound value of checkpoints. However, the method can not calculate at high speed when many connections with large allowable end-to-end delays are established. The purpose of the paper is to improve the previous method. In this paper, we clarify that we do not have to execute the point schedulability check for an interval of checkpoints which are less than the upper bound value in the previous method, and based on the fact, high speed calculation can be attained. Numerical examples show that the proposed method drastically decreases the calculation time when many connections with large allowable end-to-end delays are established.
