OSI model question

lildeezul

HI, The OSI model consist of Appl., Pres, Session, Trans, Network, Data-link, and physical.

in the book it is expressed in that order.

and although application is first on the list, it is the 7th layer.

so in a networking, does physical layer comes first right?

srry for the newb question!

markzab

Application - Layer 7 (highest)
Presentation - Layer 6
Session - Layer 5
Transport - Layer 4
Network - Layer 3
Data Link - Layer 2
Physical - Layer 1 (lowest)

lildeezul

ok thanks, but what actually occurs first.

also, theres been some subsiding with the odom press book, and todds book.

i have todds 4th edition, and i was looking to get the 5th edition, or another book.


i am just starting out, and dont any networking experience.

which book is better for people just starting out, and learning about networks.?

and whats the latest edition for odoms book

markzab

lildeezul wrote:

ok thanks, but what actually occurs first.

also, theres been some subsiding with the odom press book, and todds book.

i have todds 4th edition, and i was looking to get the 5th edition, or another book.


i am just starting out, and dont any networking experience.

which book is better for people just starting out, and learning about networks.?

and whats the latest edition for odoms book

I'm not quite sure what you mean by first. If you mean from our perspective than it is the application layer because that is based off the program/application/whatever that we are using. It then moves down the chain of command and exits onto the physical media via the physical layer. This is all explained in your books and this is the core of everything network. I would suggest knowing the OSI like a preist knows his bible. Hands down.

lildeezul

lildeezul wrote:

ok thanks, but what actually occurs first.

also, theres been some subsiding with the odom press book, and todds book.

i have todds 4th edition, and i was looking to get the 5th edition, or another book.


i am just starting out, and dont any networking experience.

which book is better for people just starting out, and learning about networks.?

and whats the latest edition for odoms book

i've seen on amazon thats is a two book set for study for both test sepately.

is there a place where i can get it cheap, that is just one book that covers of all the CCNA (640-801)

ignign0kt

Let's say you sending a packet to another host on the network. Your computer will create the packet (Starting at layer 7, and going down to layer 1), and transmit the data over the cable. When the other computers NIC recieves the data, it starts at layer 1 and goes up to layer 7. So it depends on the perspective.

Cucumber

ok thanks, but what actually occurs first.

There is no first and last layer.
It depends on wether a device is sending data or receiving data.
For devices sending data to others, the Layer7 "occurs first'. For devices receiving data, the Layer1 'occurs first".

For instance. if you are sending an email from your computer, the Layer7 "occurs first" then Layer6, and so on until Layer1.

When the mail server receives the email that you just sent, at the mail server, the Layer 1 "occurs first", then Layer 2 and so on up to Layer7.

lildeezul

oh i see, thanks for the clearification cucumber, and ignign0kt

lildeezul

any info on starter books, should i stick with todd's 4th edition or odoms cisco press.

im just starting networking BTW

markzab

lildeezul wrote:

oh i see, thanks for the clearification cucumber, and ignign0kt

What am I, horse poop?

lildeezul

lol forgot to add your name.

here it is.


Thanks for the help markzab

markzab

I was just kidding man.