Solved

Session Layer

Posted on 1999-01-08
1
275 Views
Last Modified: 2013-12-23
Dear all,
    I have a very confusing question to ask... about the session layer of the OSI model.
    if I run ls& on unix, will it go thru telnet (the application layer), the presentation layer and the session layer to the transport layer? If I run another ls program on the same machine, will another seperated session layer be created?.. or both ls will run under one 'session' mechanism.

Thanks

The confused
Jacky
0
Comment
Question by:whluk
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
1 Comment
 
LVL 7

Accepted Solution

by:
yoren earned 50 total points
ID: 1582868
Jacky,

The OSI model refers not so much to the specifics of an implementation as to the concept of how two computers communicate. There's no specific "OSI session" mechanism. When you run 2 "ls&" commands, UNIX creates 2 processes. That has nothing to do with OSI. The OSI model can, however, be used to describe what happens when you type "ls".

Application: You type "ls" into your telnet program
Presentation: Your message is interpreted using the ASCII character set.
Session: Send this message to TCP/IP port 23, since that is the port for Telnet
Transport: TCP (part of TCP/IP): make sure the message gets there
Network: IP: route the message across the Internet to the UNIX box
Link: Use Ethernet
Physical: the actual wire it goes across
Link: Use Ethernet
Network: IP: receive the message
Transport: TCP: let your computer know the message arrived
Session: Receive the message from port 23 (not exactly accurate, but conceptually right)
Application: Your UNIX shell receives the command "ls"

Yuval
0

Featured Post

Free NetCrunch network monitor licenses!

Only on Experts-Exchange: Sign-up for a free-trial and we'll send you your permanent license!

Here is what you get: 30 Nodes | Unlimited Sensors | No Time Restrictions | Absolutely FREE!

Act now. This offer ends July 14, 2017.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Even if you have implemented a Mobile Device Management solution company wide, it is a good idea to make sure you are taking into account all of the major risks to your electronic protected health information (ePHI).
During and after that shift to cloud, one area that still poses a struggle for many organizations is what to do with their department file shares.
If you're a developer or IT admin, you’re probably tasked with managing multiple websites, servers, applications, and levels of security on a daily basis. While this can be extremely time consuming, it can also be frustrating when systems aren't wor…
There's a multitude of different network monitoring solutions out there, and you're probably wondering what makes NetCrunch so special. It's completely agentless, but does let you create an agent, if you desire. It offers powerful scalability …
Suggested Courses

705 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question