Standard routers use Simple First-In-First-Out (FIFO) queuing, which is disastrous for latency-sensitive applications. When a large download starts, it fills the buffer, causing your SSH session or VoIP call to lag. This is known as bufferbloat. To solve this, we move beyond the GUI of consumer routers and into the realm of Linux Traffic Control (`tc`) and Active Queue Management (AQM).
By implementing the Cake or FQ_CoDel queuing disciplines, we can ensure that small, time-sensitive packets are prioritized over bulk data transfers. Using a dedicated Linux-based gateway (like OpenWrt or a custom PC), you can define classes of traffic and assign bandwidth guarantees. This isn't just about limiting speeds; it's about shaping the flow of data to match the physical constraints of your ISP link.
Command-line mastery of `tc qdisc` allows you to simulate network conditions, drop malicious traffic patterns at the ingress, and ensure that your workstation always has the lowest possible latency. In the world of high-performance computing, the network is often the bottleneck. We eliminate that bottleneck by applying hardcore engineering principles to every packet that leaves our NIC.