Latency

What Is Latency?

Latency refers to the duration it takes for data to transport from one Internet point to another. You can simply interpret it as the time needed to get a response after you operate on the network.

This process includes steps such as data encapsulation, queuing, data transmission, data decapsulation, etc., and is usually denoted by Ping for its completion time, with milliseconds as the unit.

Although the current data transmission speed on the Internet is extremely fast, but limited by geographical distance and network equipment, the latency can only partially become zero. The lower the latency, the quicker the corresponding, and the greater the user experience. Therefore, latency is critical for real-time applications such as online gaming, video conferencing, and online calls.

Common Causes of Latency

・Propagation Delay

The transmission of signals from source to destination through a medium causes latency, which is a physical factor that cannot be changed. For example, the length of the fiber optic cable directly affects the propagation delay because the signal must travel the physical length to reach the receiver.

・Queueing Delay

In the transmission process, data will be forwarded through various routers and switches. Each link needs to wait according to the queue length and discard policy, and so generate a certain latency.

・Processing Delay

The processing and conversion of data on each device also require time, such as route finding, security checks, and other operations will bring additional processing delays.

・Network Jitter

The actual arrival time of data packets fluctuates due to changes in the conditions of different transmission paths in the network, i.e., a kind of random latency energy that occurs in the network environment.

Difference Between Bandwidth and Latency

Bandwidth is not the same concept as latency denotes, it is the maximum amount of data that is transmitted across a network in a given time interval.

Suppose you want to transport 100 kg of apples to your friend. Bandwidth is like the carrying capacity per trip (10kg by bicycle, 50kg by minivan), while latency is the time it takes for each trip to deliver the apples to your friend.