[PLUG] Linux OSI Model

[Rick Konold]

On Sunday 24 March 2002 12:02, you hammered the keyboard to write:
> On Sun, 24 Mar 2002, Rick Konold wrote:
> | I was doing some reading that covered the OSI model again, and remembered
> | learning that Microsoft has combined some of the layers so that their
> | implementation is actually 4 layers, but includes all of the 7 layers of
> | the OSI model.  Does Linux use all 7 layers ala the OSI, or are some of
> | them combined?
>
> OSI was a nice theory...
> Does anything (outside of government) use all 7 layers of OSI?
> Not that I know of.  TCP/IP is a 4- or 5-layer model.
> Linux doesn't even pretend to use the OSI model.

Does Linux use TCP/IP as the model?  I mean, I am trying to get a picture of 
what happens from the Application level to Physical level in Linux.  So far, 
I have this picture:

Application level : FTP, HTTP, SMTP etc.
(I assume the session level is rolled into the application level)

Transport Layer : Port / sequence numbering (any error checking here?)
TCP UDP (any others?)

Network Layer : IP addressing 

Data LInk Layer : (this is done on the NIC?) Hardware addressing. Error 
checking (any packet sequencing at this level?)

Physical Layer : the actual transmission via Ethernet or ? electrically 

Does this look correct?
Are packets sized at the transport layer?

>
> | Also, when using bitwise notation for a subnet mask, will the routing
> | table actually accept /20, or do I have to write it out as 255.255.240.0
> | ?
>
> don't know.

Thats ok, I can wait until I get the router working and try to change it then 
to see what happens.