Optimization Design of Dual Redundant Networks Based on Packet Delay and Dropping During Switching
Xiangying Kong, Cuntian Hu · 2023
Mission critical control systems such as electronics, rail transit, and weapon equipment typically use dual redundant networks to improve communication high availability, which means switching between two networks to ensure that the system can continue to operate in the event of a network failure. However, both link on/off detection and new link establishment require a certain amount of time, which is the time for dual network switching. During this time, the pending messages submitted by the protocol stack to the faulty network card were not actually sent to the network, resulting in a “frame loss” phenomenon during switching. On the basis of analyzing the switching mechanism of dual redundant network cards, this article proposes an optimization mechanism for packet dropout processing based on packet delay during switching. By increasing the sending packet buffer and resending packets stuck in the sending buffer of the faulty network card, the number of frame dropouts caused by switching can be effectively reduced, and the reliability of network communication can be improved.