Linux Journal has published several interesting articles on Linux networking. Here are some of the most interesting of them.
Queueing in the Linux Network Stack tells that packet queues are a core component of any network stack or device. They allow for asynchronous modules to communicate, increase performance and have the side effect of impacting latency. This article aims to explain where IP packets are queued on the transmit path of the Linux network stack, how interesting new latency-reducing features, such as BQL, operate and how to control buffering for reduced latency.
Linux Advanced Routing Tutorial article describes how to use two different Internet connections and split the traffic intelligently between them.