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

Os, why we say" OS is a resource allocator" and “OS is a control program"?

why we say" OS is a resource allocator" and “OS is a control program"?

What is a file, What is a file? A file is a named collection of related...

What is a file? A file is a named collection of related information that is recorded on secondary storage. A file having either programs or data. A file has particular "structu

Explain the per thread scoping, Explain the Per Thread Scoping Thread-l...

Explain the Per Thread Scoping Thread-level programming introduces new twists for application-level variable scoping. Threads are commonly used in one of two ways. To ex

Major advantage of the layered approach to system design, Q. What is the ma...

Q. What is the major advantage of the layered approach to system design? What are the de-merits of using the layered approach? Answer: As in all cases of modular design as well

What are the different directory structures, What are the different directo...

What are the different directory structures? Explain each type. There are five dissimilar directory structures: 1.      Single level directory 2.      Two level directory

Mark-sweep, The objects that a program can access directly are those object...

The objects that a program can access directly are those objects which are referenced by local vari-ables on the processor stack, or by any global/static variables that refer to ob

Difference between threads and processes, Difference between threads and pr...

Difference between threads and processes 1. Thread is flow of implementation. Process is group of instruction which is alike to that of a program except which may be stopped an

Differences among user-level threads and kernel-level thread, Q. What are t...

Q. What are two differences among user-level threads and kernel-level threads? Under what situations is one type better than the other? Answer: (1) User-level threads are un

List the various file attributes, List the various file attributes. A f...

List the various file attributes. A file has particular other attributes, which vary from one operating system to another, but typically having of these:  Name, identifier, typ

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