question about file sharing sites

Replies

• 

  Leo

  Hi buddy its not that difficult, by the way lets take rapid share as an example.
  
  When you go to create an account on #-Link-Snipped-# it gives option of creating a free account and premium account. Once registered they save your status as free or premium user in database. If you are free user then your file status is saved in their database along with the date of upload which they hold as deadline to days they will delete your file as free user, meanwhile if someone download that file may be free or premium user, deadline base changes to date of most recent download. This conditions does not apply to premium users.
  
  When someone downloads file from #-Link-Snipped-# it again asks for free or premium user. As per user details, it sets cache in your system. It uses a Java script for taking time to provide bandwidth to free user and transfer starts via File Transfer Protocol and as we know for file transfer it uses Data line and Control line, i.e using two ports data is transfered from which data line sends data and control line keeps information about user being free or premium. So if connection drops even for a while (which is held as download completed)then free user can't resume download, and premium resumes download as many times he/she wants.
  
  So as as uploading an .exe file is concerned they are just stored not executed, also .exe file can't harm a Unix or Linux system because all pro ftp servers are either Linux or Unix. And so far as security matter, for why they pay ethical hackers for, just sit and do nothing. Administering network seems easy just by name but not that easy task, for more info read "Complete Reference Linux" By R. Peterson.
  
  I hope nothing was difficult to understand. Feel free to ask if not understood any point.Happy Computing.
• 

  computeridiot007

  whether uploaded file in server can be corrupted after a long period of time.And one more doubt,while downloading how the copy will be sent from a server to client and when multiple people are downloading there won't be any clash or ddos attack might not occur.
  .And also if possible explain the principle beyond download managers .I mean that how they download that file from server .why browser is not able to do at that speed .What is the tehnical reason behind this.
  These might be stupid questions plz can you explain it.I'm unaware of that.
• 

  Leo

  Hi buddy it is possible that a file may get corrupt after a long period of time.
  You might not be knowing there are several FTP servers, all files are not stored in same FTP server and FTP itself is capable of handling multiple request so there is zero possibility of any DOS attack, you can't do it on a server which needs authentication and which also keeps record of IP address while creating connection, even premium users are not allowed to download files from two IP addresses.
  
  Download managers are able to download files at higher speed because they download file by breaking it into pieces. For example, consider you have a rope which is 40 meters long, and you want to take that rope from one room to another and you have ample space to move from one room to another room. Now suppose that rope is your file, room1 is server and room2 is client, the space you gonna use to move rope is your bandwidth. If you hold one end of rope in room2 and pull it until is completely moves to room2, then of course it'll take time even though you have ample space to move same rope. This is how your browser downloads file. Now fold the same rope equally 4 times, then it'll become 10 meters long, the only difference is that now you will be holding 4 folded ends of same rope, now pull rope in room2 and you will take less time. Now open all folds and your rope will be again 40 meters long, the only difference will be that it will use maximum of available space.
  
  All download mangers first count size of file on sever and decide in how many chunks it should be downloaded so that available bandwidth can be used effectively for downloading at faster speed.
  I hope that was quite easy to understand. Happy Computing.
• 

  computeridiot007

  tons of thanks buddy.I have so many doubts.i will ask one by one.