Re: Session layer in OSI and TCP/IP

[dwg5901 () fhda edu]

I would say that's substantially correct, yes.

In the world of the Internet as it has evolved, sessions are usually a
host-based phenomenon and not a network service.  When I began to work
with communications between computer systems, it was routine to physically
connect to a network, authenticate to establish one's right to use the
network, request a connection to a destination (host or service), snd tear
that down again once communication was completed.  I think the closest you
are likely to see to that these days is as a wireless client,
authenticating and associating before packets will be transported on your
behalf.

David Gillett



> Hello!
> I've certain questions regarding how session layer functionalities are
> implemented in OSI and TCP/IP. I know that there's no session layer in
> TCP/IP. I just want to focus on its functionalities.
>
> According to OSI model session layer provides connection establishment,
> management and termination. So does this mean that in OSI TCP 3-way
> handshake and graceful connection termination is initiated by session
> layer
> and the transport layer is concerned with data transfer and reliability of
> communication only?
> But in TCP/IP the connection establishment and termination along with
> reliability are part of the transport layer and no session layer is used.
> Is
> this statement correct?
>
> Eg.- I want to browse a website.
> a) So according to OSI, firstly I resolve domain name using the DNS in
> application layer, then my web browser asks the session layer to initiate
> a
> session. Session layer asks the transport layer to make suitable TCP
> packets
> to perform a 3 way handshake. Then HTTP packets are transported using the
> transport layer.
>
> b) According to TCP/IP, firstly I resolve domain name using DNS in
> application layer. Then my application layer requests the transport layer
> to
> connect to a webserver on port 80. Transport layer makes a TCP 3-way
> handshake. After connection establishment HTTP packets are transported
> using
> transport layer.
>
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------------------------------------------------------------------------
Securing Apache Web Server with thawte Digital Certificate
In this guide we examine the importance of Apache-SSL and who needs an SSL certificate.  We look at how SSL works, how 
it benefits your company and how your customers can tell if a site is secure. You will find out how to test, purchase, 
install and use a thawte Digital Certificate on your Apache web server. Throughout, best practices for set-up are 
highlighted to help you ensure efficient ongoing management of your encryption keys and digital certificates.

http://www.dinclinx.com/Redirect.aspx?36;4175;25;1371;0;5;946;e13b6be442f727d1
------------------------------------------------------------------------