Final week, we wrapped up a five-part podcast particular that actually explains how the web works.
This sequence describes exactly how information strikes all over the world, masking the fundamentals of web, transport networks, information facilities, the cloud, and WAN alongside the way in which.
On the finish of every episode, I believed it could be enjoyable to narrate what we talked about to an actual world instance: the lifecycle of a YouTube video.
To color the total image, I’ve compiled each bit of the story right here. Maintain studying to learn how a video goes from one digicam to thousands and thousands of screens all over the world.
Step 1: Perceive That the Web Is a Community of Computer systems
Step one is for our content material creator—we’ll name him Gary—to movie himself doing one thing, like demonstrating a guitar riff, skateboarding, or a very sophisticated origami.
The sights and sounds of this video are transformed by Gary’s digicam and microphone into 1s and 0s and downloaded to his laptop.
After any edits are made, Gary uploads the video to his YouTube account. His laptop breaks the video into packets, every with an IP handle directing them to the server house YouTube has allotted for him in a neighborhood Google information heart.
Simply to make clear, YouTube is owned by Google, and though Google’s actual company identify is Alphabet, we are likely to confer with it as Google.
After Gary’s native web service supplier (ISP) connects with Google utilizing his autonomous service quantity (ASN), the packets are on their technique to Google’s servers.
Relying on the place Gary lives, this journey might take the packets on a easy path between only some suppliers, or a posh path by way of a number of totally different web spine suppliers’ networks.
As soon as it arrives on the information heart, Gary’s video is listed for search and once more separated into packets to be unfold across the YouTube community.
Throughout this journey, the packets will get new IP addresses primarily based on their locations, and varied web suppliers will trade visitors with one another by way of IP peering or transit agreements. The packets could wind up taking totally different paths earlier than being reassembled right into a video.
Viewers all over the world can now watch it with out the latency they might expertise if the video had solely been saved in Gary’s native information heart.
As soon as a viewer sees the new video and hits play, it begins the journey again from the info heart to their system.
The video is once more cut up into packets from its residence on a server in YouTube’s nearest information heart and given IP addresses that inform the packets to go to the viewer’s ISP after which system.
As soon as once more, the packets will take a seemingly random journey, probably throughout a number of totally different networks, and be reassembled collectively on the viewer’s system!
Step 2: Tunnel Deeper Into the Bodily Transport Networks
Now let’s begin over and watch the situation unfold by way of a special lens.
Gary movies himself doing one thing else, like demonstrating do a wheelie on a mountain bike, draw a dragon, or make the proper soft-boiled egg. He edits the video and uploads it to YouTube.
The bits depart his home and journey by way of wires which are both buried or hanging on poles in his neighborhood till they get to the primary aggregation level, the central workplace, someplace in Gary’s city and even neighborhood.
There, the bits depart their ISP’s community and hop onto a regional center mile supplier’s community—on this case, possibly one touring alongside a railroad line towards the closest main metropolitan space.
As soon as the packets attain the massive metropolis, they’re routed to an web trade level (IXP), positioned in an enormous windowless constructing the scale of a large warehouse the place dozens of carriers interconnect. Simply down the road is one other huge constructing owned by Google that homes YouTube servers.
Let’s assume that Gary is a fairly fashionable influencer, so subscribers are instantly alerted and begin streaming the video.
Copies of the packets then go to YouTube’s servers all around the world, first throughout terrestrial hyperlinks between IXPs, then hitting submarine cable stations and touring throughout the ocean, the place they then do the entire journey in reverse to get to the followers downloading the movies.
Step 3: Add Geography Into the Combine
On the finish of our information heart episode, we shift our focus to the place the video really goes.
On this instance, let’s say the content material creator is me, and I add a video explaining the web to my YouTube account.
I occur to reside in western Loudoun County in Northern Virginia, which is conveniently down the road from Information Heart Alley. As a result of I’m so shut, my incumbent telco broadband supplier most actually has fiber instantly right into a impartial information heart, corresponding to one of many many Equinix services.
If I lived farther away or had an alternate supplier, my video may first go to a impartial information heart to get handed onto a spine supplier’s community earlier than discovering Google.
Nevertheless, my broadband supplier seemingly has a cross join or is in a meet-me room the place they will move my visitors on to Google. Google is then prone to retailer my video in their very own information heart proper down the road.
My video is now sitting on a server stuffed with different YouTube movies in a rack someplace down an extended hallway inside one in all Google’s two Loudoun information facilities.
From there, Google will decide the place it must cache my video, primarily based on the geographic distribution of my viewership, and certain ship it all over the world through the transport community spine to its different information facilities.
Step 4: Discover the Path to the Cloud
Let’s return to Gary to clarify his relationship with the cloud.
This time, Gary movies 1.5 hours of footage for his 30-minute present. Moderately than tie up native bandwidth, he shops this video on a paid service like Google Cloud.
He makes use of a software-as-a-service device like Remaining Minimize Professional hosted within the cloud to do his enhancing, leaving the unique footage on the cloud server and saving the edited model as a brand new file there.
Throughout the enhancing course of, Gary splices in some inventory footage (content-as-a-service, actually) from a subscription service with copyright free photos. He does the identical for music, utilizing a service the place creators can choose inventory music with the right license for his or her present sort.
Lastly, as in different eventualities, Gary sends his video off to be saved on Google’s servers and cached primarily based on his viewership.
Step 5: Take a Stroll on the Company Facet
Our closing episode within the sequence focuses on company networks, so I’ve to change our use case a bit. (As a result of company staff do not watch YouTube throughout work hours, proper?)
This time round, let’s think about that HR has requested some would-be actors to remain late and document a brief video about correctly fill out a TPS report.
After enhancing collectively the superb performing and appalling royalty free company music, HR uploads the video to their cloud supplier’s storage nearest to the HQ the place that is all happening.
The video goes by way of their SD-WAN system within the workplace, which selects the very best performing path between that web site and the closest information heart. The WAN is linked at that information heart to their cloud supplier’s community, and the video goes and sits on a server devoted to that firm.
That video then will get encrypted and despatched throughout the WAN to all the varied information facilities across the nation, or world.
After every native workplace downloads the video on the WAN from the closest information heart, it runs a coaching seminar to evaluation with its staff, who then should fill out a check to verify they have been paying consideration.
Distant staff watch a reside stream of the coaching session, linked through some safe tunneling over the web—defending these TPS commerce secrets and techniques.
