The Great Packet Parade

Alright, la.

I’m Mr Scouse Network Frog.

Today we’re learning

how computers talk.

Ribbit.

Pack it!

Send it!

Route it along!

That’s how computers all get along!

Big message?

Chop it into packets.

One!

Two! Three!

Four!

Off they go, lad.

Every destination

needs an address.

DNS takes the name and helps find the IP.

Router says: “Where you going,

mate?”

Then sends the packet on its way.

Hop.

Hop.

Hop.

Very frog-like.

Now TCP... TCP likes to check

things actually arrived.

“Did you get that,

la?”

UDP?

UDP just sends it.

“Off it goes.”

Hang

on. Why’s there a beat?

Oh. We’re doing this now.

Packet on the wire,

little box full of data,

router reads the destination,

sends it on later.

DNS got the name,

IP gives location, hop through the network,

that’s navigation.

TCP checks: “Mate, did that arrive?” UDP sends it out and keeps

the thing live.

Ports on the machine,

different doors, different jobs,

find the right service when the traffic knocks.

PACKET!

ROUTER!

DNS!

Latency means waiting, bandwidth means flow,

one is how long,

one is how much can go.

Packet goes missing? Gone walkies,

has it?

Retry where needed,

carry on with it.

Cache it nearby if you’ll need it again,

save another trip across the network and back again.

Pack it!

Send it!

Route it round!

Hop through the network,

machine to machine, addresses and packets,

everything in between!

Ribbit.

Not bad that.

Anyway...

Where were we?

Ah yes.

HTTPS. HTTPS helps protect web traffic

with encryption. Very sensible.

Packet missing?

Try again.

Need the same data twice?

Cache it. What finds the address?

DNS.

What moves the traffic?

Routers.

Reliable delivery? TCP.

Fast simple sending?

UDP.

Pack it! Send it!

Route it along! That’s how computers all get along!

I’m Mr Scouse Network Frog.

And remember:

the internet is mostly lots of computers agreeing how to talk.

Mostly.

Ribbit.