Networking Tutorials

OK, this tutorial will be very advance.

contents~

-architecture of the Internet
-components of a network


*****Architecture of the Internet******

Well, what do u think a Internet is.

when i was still a noob in networking, some one told me that Internet is the biggest part of out life.

well, before i have a feeling that it was wrong about what he said.

and now, it proves me right.

because the components for the internet architecture is

1.Network
2.end users
3.end user devise
5.devises
6.servises
etc....

Well, why do u think we can acces the email server for gmail, hotmail, yahoo.???

it is because at the back, there is a email server connected to the outside world
using the servise from the ISP.

why do u think they have our records for our pass, and usernames????

it is because there is a MySQL server in some of the network pc.

u just need to ask zach, and ask if he had made up a MySQL server for this site.

Basically, Internet means

--Interconnected network.

the creation for web browsers had made our lives 100000000000000000000000000 times easier.

From hand written letters and needs like 3 days to send it.

but now, is fast typing using our keybords and we only needs the maximum of one our and arrive to our destination, depending on our traffic between the source and the out side world. and the reciever.

so , for the archetecture for the internet is bascially saying the architecture for networking.

four fundamental things for the structure of internet aka network.

1. Qos - quality of servise*
2.fault tolerance*
3.scabability*
4.security*

****Qos*****
this is very very important,

Qos refers to the mechanism that manage the congested network traffic.

more communications means more network bandwidth needed.

Network bandwidth is the measurement of data carrying capacity of the network traffic.

for example, Voice over IP phone and a peer to peer network transfer would effect the traffic of the network greatly.

you can kind of understand the meaning of quality of service.

now, i am the network manager, my customers or users is using VOIP and there is

some one doing some peer to peer transfer.

if the user that uses VOIP get delayed calls or laggy transfer of signals, then they won't use VOIP no more.

peer to peer network network bandwith measure = 20 %
-not so important

VOIp takes 20 %

but VOIP customers some times pay to use this servise, if they get leggy or delay phone calls then they won't use it any more.

but for peer to peer network transfer, it is not that important, but it takes up bandwidth too.

so what we need to do here is to set priorities.

the Router will the the classify and direct the messages according to there priorities.

so doing this job of giving different traffic priorities is very important.


another example, a web page set up meeting and email server meeting.


what do u think????

If i am a network manager. then i will give the priorities to the web page set up first.

because with out the web page , how are we going to get our email server in use by users?

think about it, with out a gmail web page and how are we going to access the email server and read our mails???

so setting priorities for different traffic is very important.

you can use priority queuing



like there is so many services, and they are all in same category or platform- the digital platform



but still there is so many different types of traffic, so putting them into there own priorities will take ages.



so u can be like,time sensitive: voice and video have higher piority then not time sensitive:email or txt documents.



after u put them in category, they are ready to be put in queues



example, the airport , the front class in one line, the businesses class in one line.



the front class get higher priority and the businesses class get lower.



same as this, the voice get the front class of the traffic and the txt & email get businesses class.

*****************fault tolerance*******

it means that, the internet will work normally even one of the components of the network is not working.

-redundancy, very very important.

for example, gmail's email server is not working, then what would happen.

is there going to be no access for email for half of the people in the world.

no, redundancy means a back up or duplicate of important service or servers.

if the mysql server is down, then there will be a backup server running until the normally email server is fix and is back to the network.



*****scalability***

is the ability of growing internally and externally without changing the originated infrastructure.


for example, adding a new user on the network should not need to be redesign the infrastructure of the network.

when u design a network, you should be havinga backup for every thing and extra.

*******security******

network security is the main concern for web providers and users.

web safety is the key part for a network management plan.

for the network security plan.

the network manager or security officer must address these two things.

1.infrastructure security
2.content security.


-infrastructure security

that means, looking up ur server room, The pc room, only allow those people who can to the server or IT room.

people can sneak in to ur server room and plug there pc in the port with a cat 5 UTP cable and they can start sniffing your traffic.

-content security
***** content security is not securing the content.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


content security means enabling

1.network availability
2.ensuring confidentiality
3.communication intergrety

1.Network availability

two things, you have to put a AV on a server and desktop and firewalls.

think about it, if your server or pc is down, how are u going to serve people, that is the availbility of the network.

2.ensuring confidentiality
that means, keeping your data secure, keeping the confidential stuff secure.

like using a strong system for user identification.

only allow the permission people to access the confidential data

using strong passwords, always make the user change there password often.

when encryption is enabled, there will be a hinger chance that hackers won't be able to see ur data even they stole it.

making password hard to guess or to crack.

3.Communication intergrety

2 types.

1. data intergrety
-the assurance of the info not to be altered during the transmission from the source to the reciever.

data intergrety can be compromised if the info is corrupted or passed up.-- willfully or accidentaly--

* if u guys have problems with this, then pm me or add me on msn.


3.source intergrety.

-.the assurance of the identity of the sender is validate.
source intergrety can be compromised when some one or devise fake the identity and give incorrect info to the recipient.

using hashes, encryption, digital sig can provide source and data intergrety across a network to prevent hackers and bad dudes like all of us in here.

and this is the end of the tutorial and thanks