Overview
Latency is often referred to as 'lag.' In networking, it is usually measured as Round Trip Time (RTT)—the time it takes for a packet to go to a destination and for the acknowledgement to return.
Causes of Latency
- Propagation Delay: The time it takes for a signal to travel through the medium (limited by the speed of light).
- Transmission Delay: The time it takes to push all the bits of a packet onto the wire.
- Queuing Delay: The time a packet spends waiting in a router's buffer.
- Processing Delay: The time a router takes to examine a packet's header and determine where to send it.