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

Why is rotational latency is not taken in disk scheduling, Why is rotationa...

Why is rotational latency usually not considered in disk scheduling? How would you modify SSTF, SCAN, and C-SCAN to include latency optimization? Most disks do not export their

What do you mean by system calls, What do you mean by system calls? Sys...

What do you mean by system calls? System calls give the interface among a process and the operating system. When a system call is implemented, it is treated as by the hardware

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

Banker''s algorithm, Consider the following snapshot of a system, answer th...

Consider the following snapshot of a system, answer the following questions using the banker's algorithm: 1. What is the content of the matrix Need? Is the system in a safe stat

What does verification represent, What does Verification represent? Ver...

What does Verification represent? Verification shows the set of activities that are carried out to confirm that the software correctly executes the specific functionality.

What is the resident set and working set of a process, What is the resident...

What is the resident set and working set of a process? Resident set is that portion of the process image that is actually in real-memory at a certain instant. Working set is th

What is the exclusive feature of unix, What is the exclusive feature of UNI...

What is the exclusive feature of UNIX Shell is the exclusive feature of UNIX.

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

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

Choice of operating systems to boot from, Q. How could a system be designed...

Q. How could a system be designed to allow a choice of operating systems to boot from? What would the bootstrap program need to do? Answer: Delieve a system that would like to

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