Loss of packets

Emails, photos, music, and videos are examples of data, among many others, sent from one end to the other (source and destination) over the Internet. 

But how can such different information travel over the Internet so fluidly? That’s because the information is divided into several “packets” with standardized sizes. 

Each of these packets contains, among other data:
- the source and destination IP address; 
- the way in which the original information is to be “reassembled” once all packets are transmitted. 
In other words, each packet is like a puzzle piece with instructions to assemble. 

Now, what happens if one or several of these packets do not reach their destination? In this case, two things may happen: either the packets are resent, or the application accepts to lower the quality and continue without the missing packet. 

In the first case, a protocol that checks the data is used, such as TCP, which, upon detecting that one or more packets are missing, requests that the lost packets be resent by the source. 

In the second case, the application may judge that it is not interesting to wait for the source to resend it, as this can impair its users experience–what happens with real-time applications, such as videoconferencing and online games, for example. In this case, a protocol such as UDP is used, which transmits information to the user in the best possible way, without caring if some data are missing, that is, if there was a packet loss. This may feel like the application is stuck, but it does not seriously affect the user experience. 

But why does this loss happen? 
The are several reasons: networks with high traffic; interference on Wi-Fi networks; bugs in software; network equipment problems; obsolete equipment with low performance; etc. 

Taking advantage of the tips from other Internet Citizen videos, to avoid packet loss you can reset your network equipment, update your software, and take steps to reduce Wi-Fi interference. 

If the problem persists, ask your ISP for help, but keep in mind that the problem may not be with your ISP, as the packets travel through multiple networks to reach their destination, and the problem may be elsewhere.

Video description

In the first scene, a man observes, with a magnifying glass, a conveyor belt with several packets sliding to the right. Above him, the phrase “On the Internet, information is divided into packets” appears. 

In the next scene, the packets enter a cell phone; its screen shows the video of a girl in a study room, dancing. Above the scene, the phrase: “And sent to its destination.” A boy, owner of the cell phone, follows the dance. 

The phrase changes to “Sometimes, some packets get lost”; and some packets start to fall off the conveyor. The phrase then changes to “The loss of packets affects the quality of the service.” The video freezes and keeps loading. The disgruntled boy shows his thumbs down.