With the maturity and proliferation of Software-Defined Networking (SDN), there has been an increasing number of network deployments that provide dedicated connections through on-demand and in- advance scheduling in support of data-intensive applications for global scientific collaboration. In such dedicated network environments, bandwidth scheduling serves as a key technique to improve the utilization of network resources and meet diverse user requests. In this paper, we formulate a periodic bandwidth scheduling problem to maximize the number of satisfied user requests for variable slot-bandwidth reservation under deadline constraint on a network path, referred to as VSBR- DC. We show that VSBR-DC is NP-complete, and propose a bandwidth scheduling algorithm based on optimal scheduling order and allocation strategy, referred to as OSOAS-BS. Extensive simulation results show that OSOAS-BS has a superior performance in terms of scheduling success ratio over three heuristic algorithms designed for performance comparison, and may be used to facilitate scientific collaboration that requires VSBR- based reservation services for coordinated data transfer over high-speed network links.