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

Explain internal fragmentation, Explain internal fragmentation The Inter...

Explain internal fragmentation The Internal fragmentation signifies to the result of reserving a piece of space without ever intending to use it. This space is wasted that this

Architects applications by making use of multitasking, Architects Applicati...

Architects Applications by Making Use of Multitasking As the capability of computer hardware keeps increasing, operating systems are presented with overwhelming opportunities.

Computer organisation, basic advantage of using interrupt initiated data tr...

basic advantage of using interrupt initiated data transfer over transfer under program control without an interrupt

Find the parent process and the child process, Q. When a process creates a...

Q. When a process creates a fresh process using the fork() operation which of the following state is shared among the parent process and the child process? 1 Stack 2 Heap

Example of producer consumer - semaphore, Now let's implement bounded produ...

Now let's implement bounded producer-consumer with semaphores, a Coke machine which is initially empty: semaphore sem_mutex = 1 // binary semaphore for mutual exclusion, 1==unlo

Define projected allocation state is safe - banker algorithm, A system cons...

A system consists of 10 units of resource class Ru. The resource needs of three user processes P1, P2 and P3 are like this                     Using Banker's algorithm, de

What are interrupts?, What are interrupts? Interrupts are in some way...

What are interrupts? Interrupts are in some ways the mainly "famous" system resources, ever since almost everyone who's used a computer has heard of them even if they don't k

Describe why sstf scheduling tends to favour middle cylinder, Q. Describe w...

Q. Describe why SSTF scheduling tends to favour middle cylinders over the innermost and outermost cylinders. Answer: The middle of the disk is the location having the smalles

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