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

Dynamic scheduling, Dynamic scheduling : The number of thread in a program...

Dynamic scheduling : The number of thread in a program may be changed during the course of operation. Dynamic priority scheduling is a kind of scheduling algorithm in which the pr

Essential properties of operating system, Essential Properties of Operating...

Essential Properties of Operating System 1. Batch: Jobs with similar needs are batched together and run through the computer as a group by an operator or automatic job sequen

What are the operations of a directory, Operations that are to be performed...

Operations that are to be performed on a directory are Search for a file: We are able to find all files whose names match a exact pattern. Create a file: New files requi

Life of a page, Suppose your process starts up, and allocates some memory w...

Suppose your process starts up, and allocates some memory with malloc(). The allocator will then give part of a memory page to your process. The OS then updates the corresponding p

How can a user program disturb the normal operation, How can a user program...

How can a user program disturb the normal operation of the system? a) Issuing illegal I/O operation. b) By accessing memory locations within the OS itself. c) Refusing to

Computers, What is operating system?

What is operating system?

Unix, what is difference between file descriptor and file pointer?

what is difference between file descriptor and file pointer?

Program of calculator and controller - fork, Program of Calculator and Con...

Program of Calculator and Controller with the fork, exec, and wait system calls The objective of this assignment is to get you to be comfortable with the fork(), exec(), and wai

How many page faults take place in lru replacement, Q. Consider the subseq...

Q. Consider the subsequent page reference string: 1, 2, 3, 4, 2, 1, 5, 6, 2, 1, 2, 3, 7, 6, 3, 2, 1, 2, 3, 6. How many page faults would take place for the following replace

Briefly discuss on real-time scheduling, Briefly discuss on real-time sched...

Briefly discuss on real-time scheduling? It is divided into two types.  Hard real-time systems are needed to complete a critical task within a guaranteed amount of time. T

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