Endtoendlatenssi

Endtoendlatenssi, often referred to in English as end-to-end latency (E2E latency), is the total time required for a data item to travel from a sender to a receiver across a system or network. It is usually considered a one-way delay, though some measurements report round-trip time. E2E latency encompasses all delays along the path and at the endpoints, including processing, queuing, transmission, propagation, and protocol or application-layer overhead.

The main components contributing to end-to-end latency include processing time at the source (data preparation and optional encryption), transmission time on links, propagation delay due to physical distance, queuing delays at routers and switches during congestion, and processing time at the destination. Additional overhead comes from protocol headers, encapsulation, and any security or data-format transformations.

E2E latency is a critical metric for real-time and interactive services such as online gaming, voice and video communications, remote control systems, and user-facing web applications. It also shapes user-perceived responsiveness in distributed and cloud-based services. Latency can vary with network congestion, routing changes, device performance, and the geographical distance between endpoints.

Measurement and interpretation: end-to-end latency is expressed in milliseconds (often with sub-millisecond precision in high-performance contexts). It is typically estimated via timestamps at the sender and receiver or through synthetic monitoring. It is related to, but distinct from, round-trip time, which measures the total time for a packet to travel to the destination and back.

Reduction strategies include optimizing network paths and routing, deploying content delivery networks and edge computing, reducing processing overhead and protocol headers, employing faster transport protocols, and using session resumption or TLS 1.3 to cut handshake delays. QoS and traffic prioritization can also help in congested networks.