Why File Delivery Order Change is Not Necessary at an Intermediate Node
Takeshi Akaoka, Shinji Sugawara, K. Yamaoka · 2019
Cache technology (e.g., P2P, CDN, web proxy, and ICN/CCN) is used for file duplication and load balancing in a file delivery system. In these systems, service latency when customers send requests and receive files is very important in file content delivery for customer satisfaction. Optimal file delivery scheduling to minimize the latency in a one-link model has already been proposed, so in this paper, we study the scheduling with fixed file sizes in a two-link model. First, we derive the optimal file delivery scheduling without changes in the delivery order at the intermediate node. We then discuss the difficulty to obtain the optimal scheduling with delivery order change at the intermediate node. We also examine the conditions of reducing the total service latency and an upper bound of the latency improvement rate. Finally, we analyze the file delivery scheduling in a general network environment and show that practical consideration of the delivery order change at the intermediate node is not necessary.