What is latency? What affects latency?

Latency measures how long it takes one packet to travel from one computer on the internet to another. At least for now, the speed of light places a fundamental bound on how quickly everything—​including information—​can move from one place to another. It takes light around 100 ms to circle the globe, so a packet can’t arrive any faster than that! However, most delays on the internet are caused by computers, not by cables.

Credits: Talking: Geoffrey Challen (Assistant Professor, Computer Science and Engineering, University at Buffalo). Producing: Greg Bunyea (Undergraduate, Computer Science and Engineering, University at Buffalo).

[vishalmahavratayajula]

Awesome explanation dude.
Makes sense how CDNs have less latency now.

[AnthonyPooran]

Thank you so much for posting this. Very helpful information!!

[pjf]

Awesome. Hard to understand all the edge CDN etc buzzwords without knowing foundation knowledge like this

[jettusjoseph]

I never seen such cool explanation anywhere else.

[carl]

Cheers man, this made a lot of sense.

[IPvpeople]

This seems to prove that basic errors can live for a long time on Youtube before being corrected.

[matheusbertimansano]

Nice Video also would be nice a full explanation of pathping and tracert each hop

[daniel.m]

Great and pure video, I like it. God bless you.

[aumshow]

Im in singapore.. how/what is the best way to reduce latency to a website hosted in ashburn va?

[dgilvani]

24, 901/186, 000 = 135ms - I never would have known this. Awesome speed standard 😊

[stephenkamenar]

"It takes light around 100 ms to circle the globe"

true of light in a vaccum. but light in a fiberoptic cable is about twice as slow.
so it takes 200 ms to circle the global.

[taranagnew]

is it the same-thing for bt audio latency?

[jdahighroller]

Handling time! Prob being scanned by multiple and different subsystems too even for a ping

[sachin]

20, 000 Kms/300, 000 Km/s = 66ms, which is 16 packets/s. The 20, 000 km is the half length of the equator. This denotes the max distance between 2 points on the surface of the earth, which is Xinghua, China to Rosario, Argentina: 19, 996 km (12, 425 mi)

[ace]

How about Latency in a geo-synchronus satellite internet, vs a low earth orbit satellite internet?

[IPvpeople]

"It takes 100ms for light to circle the earth" This is not true. It is 200ms. Calculation base: Circumference earth is 40.000km. Speed of ligth through glass is 200.000km/s (through free space it is 300.000km/s). So: 40.000/200.000 = 0, 2 seconds is 200ms.