Latentie

Latentie, also known as latency, refers to the delay between a cause and its observable effect in a system. It is typically measured in units of time, such as milliseconds, and is a key metric for responsiveness. Latentie can be described as end-to-end or one-way, with end-to-end latency often including a return path that yields the round-trip time (RTT). Jitter describes the variation in latency over time.

In telecommunications and computer networks, latency is composed of several components: propagation delay, transmission delay, processing delay, and queuing delay. Propagation delay depends on the physical distance and the speed of the signal through the medium. Transmission delay relates to packet size and link bandwidth. Processing delay arises from the time devices take to examine and forward packets. Queuing delay results from traffic congestion and buffering. The sum of these delays gives the end-to-end latency between sender and receiver.

In computer systems, latency encompasses memory latency (time to access data in memory), storage latency (disk or flash access), CPU and GPU processing delays, and input/output delays. Low latency is crucial for interactive applications such as gaming, trading platforms, and real-time analytics, while higher latency can degrade user experience and system performance.

Measurement and mitigation: common tools include ping for round-trip time and traceroute or MTR for route inspection. Reducing latency can involve upgrading network links, deploying content delivery networks, using edge computing and caching, optimizing software protocols, and reducing processing overhead. Techniques such as asynchronous I/O, parallel processing, and quality of service prioritization also help lower effective latency.

Applications and relevance: latency affects the perceived immediacy of responses in real-time communication, immersive media, and interactive services, shaping design choices across networks, computing infrastructure, and application software.