What is ping and packet loss?


What is ping and packet loss?

In: Technology

As I understand it ping is like yelling to your friend and then your friend responds. The time between those shows the delay. Packet loss would be you handing candy to your friend, each one a packet, and how many get dropped(lost) between the transfer is packet loss.

Ping is how long it takes one computer to send data to another one and get a response. Sort of like an echo. Or playing catch – How fast you can throw a ball to someone else and get it thrown back. Lower ping is better, it means you can send and receive quickly.

Packet loss = how much data is actually lost in sending/receiving due to screwy connections. If there’s a lot of packet loss your download and upload speed to that other computer are going to be bad because you gotta send/receive the data multiple times for it to transfer 100%. Usually more noticeable in streaming things like online games and movies.

Your computer tries to reach another device sending a packet of data. It is a packet of type ICMP and is specifically designed for getting a reply from whom is pinged. Upon reception, the other device sends back an answer, sometimes referred to as a pong – that is also an ICMP message. Those packages cross the network and after some time, if everything goes right, the pong arrives back to your computer. Your computer usually shows the time that round trip took

However, packets may get lost. Reasons can be incorrectly configured network, incorrect routing, no connection to the network (not plugged in), bad quality of the connection – then the packet gets lost in noise, collisions with other packets (multiple devices send something at the same time resulting in not understanding anything), … Your pinging device waits for some time, and if it doesn’t receive that pong in time it is considered lost.

Others have answered the question really well, so here’s a bonus explanation of a third related idea:

Sometimes, when talking about ping and packet loss, we also talk about ‘jitter’. Ping is how long another computer takes to reply when you send it a message asking it to reply. ‘Jitter’ is how much that reply time changes each time you do a ping.

So if you ping a computer and it replies in 15 milliseconds, and then you ping it again and it replies in 500 milliseconds, and then the third time it replies in 15 milliseconds again… you have jitter.