Internet Servers

[jmcdonald18]

My question is suppose a user has two browser applications active at the same time and suppose that the two applications are accessing the same server to retrieve HTTP documents at the same time. How does the server tell the difference between the two applications?

 

[kmote]

It doesn't, why?

 

[jmcdonald18]

you sure there are not seperate sessions for each application so that data is sent to the correct place.

 

[kmote]

If a request is coming from the other side of a NAT, a webserver isn't even going to know for sure that the requests aren't coming from different machines.

A normal webserver setup will not spawn a server process to handle a http session like telnet or ftp.

 

[CntdwnToExtn]

Just to expand a little more, have a look at the OSI model for networking.
OSI model - Wikipedia, the free encyclopedia

It's able to show you each step in the network transmission.
So when the Web server sees the request for a file, it just knows what IP to send it back to and what protocol to use (TCP, UDP, etc). Once the data gets back to the IP, usually NAT come into affect and looks at it's own routing table to determine what computer made this request. Once determined it will pass that information along where the computer will then determine what piece of software, application, etc that made the original request.