Trafikshaping

Traffic shaping, or trafikshaping in some languages, is a network traffic management technique that regulates the rate at which data is transmitted to conform to a specified bandwidth limit. By delaying or buffering packets, shaping smooths traffic bursts and helps prevent congestion, providing more predictable performance for prioritized applications and services.

Shaping relies on queuing and scheduling policies that control when packets are transmitted. Techniques include token bucket and leaky bucket algorithms, which enforce a long-term average rate, and priority or weighted fair queuing to allocate bandwidth among multiple flows.

It is distinct from traffic policing. Shaping slows traffic by delaying packets to stay within a configured rate, while policing may immediately drop or mark packets that exceed the limit. Shaping emphasizes smoothness and delay, whereas policing emphasizes enforcement.

Typical uses include Internet service providers shaping consumer traffic to prevent network oversubscription, and enterprise networks shaping traffic to guarantee performance for real-time services such as voice and video, or to manage backup windows and bulk transfers.

Implementation is common in routers, switches, and host systems, often via quality of service (QoS) features. In Linux, tools such as traffic control (tc) implement shapers and queuing disciplines; in enterprise and carrier networks, devices and SDN controllers provide policy-based shaping.

Limitations include added latency and jitter, potential inefficiency if misconfigured, and the possibility that traffic shaping does not address underlying congestion. Proper tuning requires visibility into traffic classes, peering links, and application requirements.