Best Network Latency Analogy

[TigerBoy]

Hi Guys,

 

 

Good day!

 

I am looking for a great network latency analogy for non-technical users. Users get why bandwidth is important when I explain using the train, printer, and especially the water pipe analogy. Though I am having a hard time explaining latency without using any or much technical terms.

 

Hope you guys have any insight to this!

 

Thanks!

[Enderman]

How long does it take your car to get from your house to work.

That's latency.

 

Also your GPS tells you where to go, the street signs tell you where you are, and the stoplights tell you if you can pass or not.

That's a router/gateway/hub and all the other stuff in between you and work.

[DrM]

mail maybe? the time it take to send someone a letter, and the time it takes for them to reply to that letter

[Dargenfire]

Imagine a highway.

 

Bandwidth is like how many lanes the highway has. The more lanes, the more cars can cross through a point per unit of time.

 

Latency, like @Enderman said, is how fast the cars get from A to B, and back again.

 

Any router or network switch/hub is like a set of traffic lights on the highways. Cars have to wait to go through them, but if someone has priority at that traffic light, then they get to skip to the front of the line waiting for the traffic light (Imagine an Ambulance running the red by using their siren, or a motorbike driving between lanes in peak hour traffic).

 

Latency doesn't matter much if I want to watch a Youtube video. I just click on the video, my little data packet car travels through the internet highway, and arrives at Youtube's servers. It then commands a fleet of trucks full of video data to trundle back to my place. Once the first of those trucks start arriving at my place, I can start watching the video and the rest of the trucks keep streaming in and unpacking their data while I watch the video. Latency is only responsible for the small delay between sending my messenger car out, and the first truck arriving back at my house.

 

Online gaming, however, is very dependant on latency. Gaming only requires little packets of information to be sent between me and the server, but requires the travel time between us to be short in order for the game to be properly playable. If my sister is causing a traffic jam on my local network because she's ordered a massive fleet of 4K Netflix trucks, and I don't have any sort of prioritising set for my PC on our home router, then my messenger is stuck in that really bad traffic, causing latency issues.

 

Just made that up on the spot. Let me know if that explanation works well.

[Wombo]

8 hours ago, TigerBoy said:

Hi Guys,

 

 

Good day!

 

I am looking for a great network latency analogy for non-technical users. Users get why bandwidth is important when I explain using the train, printer, and especially the water pipe analogy. Though I am having a hard time explaining latency without using any or much technical terms.

 

Hope you guys have any insight to this!

 

Thanks!

When they inevitably ask you a question about latency, wait 10-15 seconds before answering, just stand there awkwardly.... waiting.

 

One part informative, one part comedy.

[Unhelpful]

33 minutes ago, Wombo said:

When they inevitably ask you a question about latency, wait 10-15 seconds before answering, just stand there awkwardly.... waiting.

 

One part informative, one part comedy.

No joke though, comedy is an excellent teacher. People remember if it makes them laugh.

[Sunshine1868]

the speed of sound... talking when next to somebody happens seemingly instantly, but if somebody claps their hands at the other end of a football field, it seems delayed....it takes time for the information to reach you since it has to travel a physical distance

[.spider.]

9 hours ago, Dargenfire said:

 

Any router or network switch/hub is like a set of traffic lights on the highways.

A switch.

A Hub is like a crossroads without any signs, traffic lights or traffic rules. A lot of collision will happen.  

[BrightCandle]

The main issue with all the usual analogies is that they are typically about travel time. But actually the grand majority of latency is in the network hardware not time on the wire, so its not really like a highway its more like a parcel that spends most of it time in sorting and a lot of time going the wrong way in the van all the time. It doesn't get to take the optimal route and so we get latencies in the hundreds between countries and yet that isn't much to do with distance at all its just increased hops and congestion.

[TigerBoy]

Thanks for all the responses guys!

 

I tried the following:

1) Distance analogy via Cars

2) Speed of sound analogy using thunder

3) Ask them to ask me what latency is

4) PING explanation (somewhat technical)

 

Surprisingly the 3rd one worked best. When they answer back I gave them another delayed answer for a few times as well to show them how much an issue it is.

 

For the somewhat tech savvy ones I explained using PING to <google.com>:

PC: Hey Google

(waits 3/4 a second)

Google: Wut?

 

Again thank you for all the answers. This is greatly appreciated.

[mariushm]

Easy ... data travels through fiber optic cables between switches, routers, computers that make up the internet at the speed of light, which is very close to 300k km/s (299 792 458 m/s), so in a very simplified way in one millisecond, data can travel up to about 300 km through fiber cables. 

 

If you're connecting to a computer located 1000 km away from you, it takes at least 3ms for your computer to contact the remote server and another 3 ms for the server to reply to your computer... it's simple physics.

 

In addition to just this (almost ideal) cost of traveling through the fiber optics, each node (a switch, a server, ISP's datacenter etc) between your computer and the destination server  may need a very small amount of time (below milliseconds) to analyze the data you sent and decide what to do with it and through which fiber cables to send it.

 

For example, if you're in Poland and you want to communicate with someone in US, the data will go to the datacenter's network, where a switch or a computer decides if it's better to move the data to a switch located in Paris, or maybe it's better to push the data to a computer in Spain, and then from one of those locations the data may go to UK and from there it may go through ocean fiber optic cable to US. Such decisions are often made depending on how busy various routes are or how cheap some routes are compared to others.

 

The further the remote computer is located, it takes more time for data to reach the remote computer and come back.

 

Latency is not only just a direct relation to distance and number of hardware devices routing the data packets around the world.  Often, the latency is increased by the ISP consciously, because your data may have lower priority compared to the data of others, and only so much data can be pushed through a fiber optic cable at one time. By delaying your data, there's more time available to push the more important data towards its destination.