How many times have you heard the words such as...WAN,PAN,ISDN,MAN and many many others, during your day at work and didn't have any clue regarding their meaning?
Well, today, I have decided that the time has arrived to clear up the mist. So I have grabbed some 5kg of Etherenet and IP literature, and opened a blog.
In this blog I will try to summarize the most interesting things I will discover while figting my way throught this book and aquiring knoledge without which I feel myself a kind of analfabet at my current working environment.
Well....Lets start!
And lets start from Introduction:
- Introduction
First - WAN,LAN...what are all these words - it's easy - Wide/Local/Methropolitan/Home or Presonal ... AreaNetwork.And why are the standarts are so important - well, have you ever tried to find your way in Beijing by asking the locals?
The OSI Model is the so well known 7 Layer model which includes:
7.Application | App.Layer Header is added. | ftp,http,voip | |||
6.Presentation | How the data is being formated in the mail box. | Code set info is added | Html,IPsec… | ||
5.Session | Maintain application sesion. | Ports | |||
4.Transport | Data delivery | TCP(Protocol used for sending the packets – when and how),UDP(low quality – good for VOIP) | |||
3.Network | Route packets | IP | |||
2.Data Link | Data framing | Ehternet,ATM | |||
1.Physical | Define/Transmit raw data over chanel | Bit stream | Modem,SDH/Sonet(Synchronous Optical NETwork),coax,wireless | ||
In other words, information related to the functions of each layer are added to the packet as it passes down the protocol stack.
Having two distant LANs, you may connect between them by using routers which interconnect networks working on different protocols.
So – routers(L3) connect different networks while switches(L2) connect same networks(lans).
Well, this is all for today, there are more 20 Chapters to go – stay tuned.
