So what's the most popular networking protocol? Find out in this video.
My name is Tim Buchalka from the Learn Programming Academy,
and this is my learn to code series here on YouTube.
And just in case you're wondering why I'm talking about computer networking protocols and so on
in the learn to code series, the reason's simple.
Just like I talked about computer hardware earlier in this course
and how understanding how things work at a hardware level is important
and will ultimately make you a better programmer, well, it's the same with computer networking.
Understanding computer networking and how computers communicate with each other
even at a high level helps you because you no longer think it's magic.
You actually understand the basics of what's happening with that communication.
Networks work correctly because they follow a set of rules known as protocols.
A simple matter for example of protocols or rules comes from all sporting events.
Football or soccer has a set of rules that guide the play-by-play.
Penalties are issued when players or coaches violate those rules.
These rules often become a set of worldwide standards
so that these games can be competitively played around the world.
Network protocol standards allow various companies
to create and build products for networking applications that are compatible
with products from other companies.
A common example of a physical standard is the universal serial bus or USB,
which allows companies to create devices
that can attach to other devices by this common USB port.
Network protocols must coordinate the transmission of messages
between the devices in the network,
and this is a very sophisticated process.
For example, what if 10 people were all to talk at the same time in a small room.
The result would be a lot of noise and probably a significant loss of any messages trying
to be communicated by these people.
The same thing would happen in a network if it didn't conform rigorously
to the protocol standard implemented in that network.
In a bus network that uses the ethernet standard which was covered in the last video,
the right to transmit messages is coordinated
by the protocol known as carrier sense multiple access with collision detection or
CSMA/CD.
This protocol states that each message is broadcast to each device on the bus,
but only the device that the message is addressed to will keep and use the message.
A device must wait for the bus to be void
of any message before it can attempt a transmission of its own onto the bus.
Back to my room full of people example.
If a person in a room is talking
all other people are hearing what the person is saying
even though perhaps the message is directed to a specific person.
All other people are silent while the person is talking.
When there's silence, then some other people may talk.
In wireless networks which usually utilize a star network
the institute of electrical and electronics engineers or IEEE
has established the 802.11 protocol standards
commonly referred to as Wi-Fi.
Now these standards utilize a protocol
known as carrier sense multiple access with collision avoidance
or CSMA/CA.
Wi-Fi cannot detect a collision due to the star configuration
so its focus is on avoidance.
Collisions can still occur and re-transmission then must be done.
Now I don't know about you but these protocols seem almost mind-boggling to me.
How can it all be kept organized.
Software controls all these transmissions
following the very rigid and strict protocols.
Any deviation from the standard will mess up the device communication across the network.
Another mind-boggling aspect of these protocols
is the speed with which they must operate at.
You and I can send a request for a website's home page
and have it show on our device in less than one second in many cases.
The last protocol topic I want to cover is the combining of networks.
In the real world picture a city
has a complex bus route system for moving people from location to location.
Bus a picks up a passenger delivers that person
to a transfer station where the person exits the bus and waits for bus b.
When bus b arrives, the person gets on bus b and is transported to
another transfer station where the person exits bus b
and waits for bus c.
Now when bus c arrives, the person gets on and rides to her destination,
another transfer or termination station.
Now with the computer network that uses a bus configuration,
the transfer station equivalent has a few different names,
repeater, bridge and switch to name a few.
The repeater passes messages back and forth between two buses
often with some amplification to boost the signal.
A bridge is more complex than a repeater
in that it only moves a message between two buses if the message is destined
for a target device on the other side of the bridge.
And a switch is essentially a bridge with multiple connections allowing it to connect
more than just two buses.
Another transfer station called a router
is used to connect to potentially different network types,
bus and star together to create an internet.
The routers are usually special purpose computers
used for forwarding messages between disparate networks allowing each network
to maintain its own protocol standard being ethernet, Wi-Fi,
CSMA/CD, CSMA/CA etc.
This is really cool and amazing technology
given the fact that in the internet messages are often broken down
into portions of a message called packets.
And packets can travel entirely different routes from point of origin
to phone or receipt at the destination where the packets
are all reassembled into the message. Again, mind-boggling what's happening behind the scenes.
My final topic related to network protocols
briefly covers client server and peer-to-peer communication technology models.
Two good examples of the client server model are a print server and a file server.
The print server can receive requests to print something from multiple client devices,
and it will cue the requests and then print the item one at a time.
A file server performs in a similar fashion, making sure multiple
client requests to read/write the same file are processed
in a first in first processed order.
Now without such technologies
we might end up with chaos when printing or manipulating files,
oh no we certainly would want that to happen.
Now with the peer-to-peer communication technology model,
each pair can provide service to and receive service from each other.
The service can stop and start on demand rather than executing all the time
as in the client server model.
Now some good examples of this model are instant messaging
interactive competitive computer games
and distributing music and motion picture files across the internet.
As I close out this video segment, I want to mention cloud computing.
In a sense cloud computing in its simplest explanation
resembles either the client server or peer-to-peer model
depending on how one chooses to describe it.
Keep in mind that cloud computing is more than just the storing of files
on cloud-based storage systems.
It also incorporates huge pools of shared computers
that can be allocated for use by clients as needed.
Now this concept seems new,
however, it has evolved from the 1970s computer time sharing era.
Now you may think you know a lot about the internet,
but don't skip over the next video
because it's going to uncover new insights that will enhance your knowledge and use of it.
Remember, the course is designed to make you a better programmer,
so please don't just assume you know all this stuff you may well find something new.
As always, thanks for watching, and I'll see you in the next video.
This is the part of the video
where I meant to get all enthusiastic and to ask you will quite literally beg you
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I'd be grateful if you do one both or all three.
More videos will get out there in front of a bigger audience if I get that level of engagement,
but obviously it's your choice.
So remember that this series was meant to be watched in order.
So if you haven't watched from the start then how dare you watch my video series
out of order.
Click the link over here to get to the first video in the series and watch that
if you want to see the entire series in order
or come over here and click to view the previous video in the series, again your choice.
All right. I'm done catch you. In the next video.