Latency

Several factors can influence your Internet quality, such as the hired bandwidth of the plan or the number of people sharing the same connection. Another important indicator to measure Internet quality is latency! 

Latency can be defined as the time variation between a stimulus and the beginning of the response to it. In networks, latency is the time between the departure of a data packet from your machine and the beginning of response on the destination server. However, to check your Internet quality, bidirectional latency, also known as RTT (Round Time Trip) or simply ping is used. Bidirectional latency is the time it takes for a packet to reach its destination and go back to its source. It can be said that bidirectional latency measures the communication delay. Therefore, the longer this time, the worse is the quality observed in services. An example directly related to latency is lag (delay) in online games. 

Bidirectional latency is measured by using ping. In fact, ping value is commonly shown among the tested items in speed tests. Even if your Internet speed corresponds to the contracted bandwidth, the perceived quality will be bad if ping is high. 

Among the factors that can influence latency are: 
- Type of connection: connections using optical fiber are faster, whereas Wi-Fi can suffer interference and increase latency;
- Distance to destination: accessing a website hosted in the United States will imply a higher latency than accessing one hosted in your city, as the data packet will pass through and be analyzed by more networks until reaching its destination; 
- Information transmitted: if several people share the same connection, latency will be higher. This also happens if the content accessed is very heavy;
- Programs or protocols in the middle of the path: for example, if the program used takes a long time to respond, or the DNS server takes a long time to return the IP of the desired page. 

Therefore, when you detect latency in your connection, check if a lot of people are sharing the same connection, or if they are using your bandwidth with streaming and torrent services, for example. In the case of Wi-Fi connections, follow the tips already provided by Internet Citizen, try to reset your router, and check if it is adequate for the hired plan. 

Test your Internet quality: https://medicoes.nic.br/

Video description

In the first scene, a thoughtful girl waits for a web page to load. Above, the phrase “Slow Internet? Latency might be the problem” appears. 

In the next scene, the girl is sitting in front of her laptop. In the background, connected circles represent the different networks of the Internet; there is a server above one of them. The phrase explains “Latency, ping, or RTT is the round trip time of a packet to its destination.” The girl types something, a data packet leaves her laptop, reaches the server, and returns from the server to the laptop. A stopwatch records the time and shows 15ms at the end, the acronym for milliseconds. 

With a magnifying glass, the girl observes the phrases “Some causes are:”; “equipment problems”; “distance to destination”; and “type of connection”. 

In the last scene, the phrase “The higher the latency, the worse the Internet quality” appears above the girl, who is next to the page loading. She puts her thumbs down with a disgruntled face.