Networking tidbits, Operating System

Assignment Help:

There is a very small amount of networking background required for Project 2. In Project 2, we want our computer (or our "host") to request information over the Internet from a remote webserver (another Internet "host"). On our computer, from within our Project 2 ap-plication, we will open a "socket", which on many operating systems acts like a ?le which you can read or write. Moving down the network stack into the operating system, a socket uses a transport protocol to communicate with the remote host. The application-layer HTTP protocol which webservers use is built on top of the transport-layer TCP protocol, which provides reliable, in-order, stream-based delivery between your socket and the remote socket. A socket also has a "port" number associated with it. When we open our socket, we will request that it opens port 80 on the remote host, since this is the port number on which almost all webservers listen for re-quests.  Finally, when opening the socket, we need to specify which remote webserver we want to communicate with, such as www.cnn.com, etc. Moving down one more layer, every host (laptop, server, cell phone, etc) which is directly accessible on the Internet has a unique network-layer IP address, such as 128.119.240.19, and most of those have hostnames, such as www.cs.umass.edu; the Domain Name Service (DNS) translates from hostnames to IP addresses.

Note that the sock.read() method is in a while-loop, since reading from a socket will return between one byte and the maximum number of bytes requested ((MAX READ-1-size) in the code above). You'll need to keep repeatedly reading from the socket again until you get all the bytes you want. sock.read() will block until it has at least one byte to return, unless its request times out (set by sock.setTimeout(5) to be 5 seconds), or unless the connection is closed.


Related Discussions:- Networking tidbits

Compute the effective instruction time on the system, Q. An operating syst...

Q. An operating system sustains a paged virtual memory using a central processor with a cycle time of 1 microsecond. It costs an additional one microsecond to access a page other

Major locking errors, When programming with threads, there are three very c...

When programming with threads, there are three very common mistakes that programmers often make: 1. locking twice (depending on the system and type of lock, can cause crashes, h

What is scheduler, What is scheduler? A process migrates among the vari...

What is scheduler? A process migrates among the various scheduling queues throughout its life time. The OS must choose processes from these queues in some fashion. This selecti

Explain briefly the working of semaphore with example ?, Explain briefly th...

Explain briefly the working of semaphore with example ? The E.W. Dijkstra (1965) abstracted the key idea of mutual exclusion in his concepts of semaphores. Definition A s

Explain process termination - operating system, Process termination A p...

Process termination A process terminates when it finishes implementing its final statement and asks the operating system to delete it by using the exit system call. At that tim

What is turnaround time, What is turnaround time? Turnaround time is th...

What is turnaround time? Turnaround time is the interval from the time of submission to the time of completion of a process. It is the sum of the periods exhausted waiting to g

Define the dosexit function used in the os/2, Define the DosExit Function u...

Define the DosExit Function used in the OS/2 DosExit(action, resultCode)  DosExit function is to be called when a thread or process is finished executing. If EXIT_THREAD is

Transportation, what are the factors influencing the choice of a mode of tr...

what are the factors influencing the choice of a mode of transportation?

Explain file allocation using i nodes, File allocation using I nodes. T...

File allocation using I nodes. This method is used to decrease the size of the table in the above method. Every file will have an I-node list. Allow a file have 15 pointers a

Explain concept of synchronization, Synchronization In communication am...

Synchronization In communication among processes messages passed may be blocking or nonblocking - also called as synchronous and asynchronous. Blocking send : The sending pr

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd