Abstract:With the aid of multipath transport protocols, a multi-homed host can transfer data through multiple paths in parallel to improve goodput and robustness. However, the receiver has to deal with a large quantity of out-of-order packets due to the discrepancy of paths in terms of bandwidth, delay and packet losses. Theoretical analysis suggests that there are two approaches to reducing the memory overhead of caching out-of-order packets. One is to minimize the quantity of packets backlogged in outgoing queues of senders, and another is to decrease the packet sending rate. From the former, the study proposes a packet scheduling algorithm, named SOD (Scheduling On Demand), which assigns packets to each path according to the free window size. From the latter, a simple flow control method is proposed, which leverages the window feedback advertisement mechanism to limit the packet sending rate. Experimental results show that compared with existing algorithms, SOD suffers from the lowest memory overhead and obtains the highest goodput when receivers enable flow control. Additionally, SOD works steadily in the cases of diverse simulation scenarios.