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+---- Thread: [TuT]Basics of Networking (/showthread.php?tid=465607)
[TuT]Basics of Networking - 0x45 - Jun 7, 2010
Basics of Networking
---By Xin R
---By Xin R
Networking - It is basically interconnection between various devices.
The ways of interconnecting and some defenitions is what we discuss in this tutorial.
There are 2 main types of interconnection.[Based on How devices are connected]
TCP- Transmission Control Protocol
UDP - User Datagram Protocol
Protocol- They are the rules by which network devices are connected.
TCP
TCP stands for Transmission Control Protocol. To make it not confusing, it is simply a 'direct' connection between various components without using a router.
When we share a file using MSN or when we download torrents, they are TCP connection as we directly connect to another computer.
UDP
UDP stands for User Datagram Protocol. UDP Networks work like both devices connect to another devise called router and it acts as a medium of transmission. Means, we send data to router and router redirects data to where we want the data to be transmitted.
For a better understandting of TCP and UDP, go here
Again, there are 3 types of network[Based on Area]
LAN - Local area network - The network we find in offices. They are avalable to that specific location only.
WAN - Wide area network - A little broader than LAN
MAN - Metropolitian Area Network - The connection is avalable to a large city.
Again, 2 types of network[Based on Connection Type]
Ethernet - Computers are connected physically or using wires.
WLAN - Also called Wifi, They are connected physically, but by using radio waves. Almost all Laptops avalable now are equiped with WLAN. If not, it costs just around 10$ to buy one reciver.
WLaN is highly insecure as compared to Ethernet as someone with a wifi card can connect to your network and browse internet or steal your data, infect you etc. If left open. However there are pros too.
IP - Internet protocol. The protocol we uses to connect devices. IP Address are addresses unique to each devise in a network and is used to identify each devices.
Two versions of IP addresses are avalable at present
IPv4 - They are like xxx.xxx.xxx.xxx where xxx are numbers, not letters and each xxx can have a maximum value of 255. Meaning, there can be 255x255x255x255 unique devices connected to a network.
IPv6 - Since the bandwidth of IPv4 is low as more and more devices are connected to internet, a new type of IP address is developed which is not used now.
IPv6 Addresses look like xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx
Where each x can be Letters(A, B, C, D and E) or numbers(decimal numbers).
basically, each x is a Hexa decimal value.
It have much more bandwidth compared to v4.
Ports- They can be compared as 'channels' in TV and IP addresses as TV itself. Meaning, within the same ip, there are many ports[Dont remember howmuch exactly] at around 65thousand with each type[TCP and UDP] with IPv4, like there are many channels with each TV. Each port is for different functions.
Some common ports are 80(Web), 21(FTP), 22(SSH), 25(Telnet) etc.
Each devise connected to network can be called a node.
Host - It is the computer or devise that transmits data.
Workstation- It is simply a computer. Donot confuse, there is nothing fancy about it. It is simply a computer.
Some people call 'high end' computers workstation.
OSI
OSI - It is a set of rules on connecting various devices. It is developed because in earlier days, different types of computers such as apple II and IBM etc could not be connected.
There are 7 Layers in OSI Model:
[img]http://blessedhands3333.com/personal_journal/images/osi_model1.jpg[/img]
Application Layer:- The so called web browsers, email and ftp clients etc. This layer interacts with user and sends and recieves data to and from its nearby layers. This is the 7th layer in OSI Model of networking.
Presentation Layer:- This layer is responsible for arranging the data orderwise according to the various frequencies by which data is recived. If this layer was not there, if someone send "Good Night", we would get it as "hGtiG Ndod" or other similar words.
Session Layer :- This is the layer that opens up the connection between host and client. Without this layer, we cant send or recieve messages.
Transport Layer :- This layer analyses the data and send it to appropriate applications. For example, if you recive a webpage, you dont want to go that data to an email client(Outlook). So transport layer in OSI model helps in this process.
Network Layer :- The MOST important Layer. This layer routes our data to destination. Think of it if the passwords we send gets routed to some other location!
Data Link Layer :- Network layer directs the data. It is transferred by Data Link layer.
It have 2 sub Layers:
- LCC Sub Layer
Physical Layers :- Those hardware parts of networking, including cables, IC Chips, Network cards etc. The bottom layer of networking and its basis.
I will update this tutorial soon with more info.
Kindly point out any mistakes and PM me or post here if there is. I am not an expert.
* - Dan08 - Jun 7, 2010
Looks good. BTW its 'devices' not 'devises'. You could expand it a little bit more but for a basic understanding it's enough. Really good :D
* - 0x45 - Jun 7, 2010
Thankyou for pointing out. Corrected. :)
* - Qkyrie - Jun 7, 2010
Maybe you can add to the ports:
ports are stored as a 16bit binary word, therefore, there are 2^16 combinations. (65536)
* - Dan08 - Jun 7, 2010
and the IPs, class A B and C ;)
* - 0x45 - Aug 16, 2010
Please post your suggestions, critics and other s..
* - omgitzkevin - Aug 16, 2010
Very helpful to someone new like me, Thanks!
* - Keypel - Aug 16, 2010
I liked it.
Nicely described.
* - 0x45 - Aug 23, 2010
THankyou. Tutorial Updated again. Rate this thread please.
* - 3v0|v3 - Aug 23, 2010
Nice Stuff. I personally liked it. Thank You.
* - endlessbounty - Aug 24, 2010
good job this explains things well :)
* - Sir SkinowZ - Sep 28, 2010
Good tutorial
Thank you 🙂
* - ac1dxtrem - Sep 28, 2010
Nice one :) Just 2 things: Telnet port is 23 not 25 and Hexadecimal goes from A to F not to E :)
* - MasterMind98 - Sep 29, 2010
Nice tutorial for the basics, well organized and easy to read.
* - 0x45 - Apr 30, 2011
(Sep 29, 2010 11:01 AM)MasterMind98 Wrote: Nice tutorial for the basics, well organized and easy to read.
Thankyou! Mastermind98!
Xin R