What is Traffic Shaping?

Some home routers, especially ones marketed to gamers, advertise traffic shaping as a tool that can help reduce lag and speed up your connection to online games. Most of these products however don’t explain how traffic shaping actually works, leaving customers in the dark.

What is traffic shaping?

Traffic shaping is a bandwidth management tool used to optimize the network connection for various purposes. The most common form of traffic shaping is “application-based”. Application-based traffic shaping is used to prioritize the transmission of important network traffic on an application by application basis. Traffic is generally prioritized because it is latency-sensitive such as voice and video communications and video games or time-sensitive such as live data feeds.

How does traffic shaping work?

Traffic shaping is supposed to speed up your network connection, ironically, it does so by selectively slowing it down. Traffic that is not marked as high priority has its transmission delayed, making way for high-priority network traffic. This provides the most advantage to latency-sensitive network traffic such as voice and video calls and online gaming, by reducing the time the network traffic waits in a queue to be transmitted.

For example, an application-based traffic shaping algorithm may delay the transmission of network packets from a browser to prioritize a video call in Skype, providing a superior video call experience.

Another type of traffic shaping, more prevalent in business environments, is known as route-based traffic shaping. Route-based traffic shaping uses information about directly connected network connections such as bandwidth, latency, and utilization, to prioritize which route to transmit certain data over.

Tip: Route-based traffic shaping is primarily used in business environments where routers often have multiple connections and can, therefore, choose which connection to use for each network transmission. This technique is not generally useful in home-routers as most home networks don’t have two internet connections and don’t have a complex enough structure to take advantage of it.

For example, a route-based traffic shaping algorithm may prioritize urgent traffic such as network packets from VOIP calls to use a network connection with lower ping and lower bandwidth and choose to send less urgent data across a connection with higher ping and higher bandwidth.

Some ISPs controversially use traffic shaping to actively slow down heavy bandwidth protocols such as torrents, and the customers who consistently use them.