Apache Web server Week 2: Application Layer This week will clarify many interesting facts about services provided by the application layer. The application layer is the top most layer in the Internet protocol stack, which helps network applications resident in different computers to communicate. The application layer contains protocols that are used by network applications to facilitate mutual understanding. Among these protocols are: the HTTP, FTP, SMTP, and etc. A distributed (also called client/server) application consists of two parts: one part runs at the client’s (user’s) site, another at the server’s site. Both parts exchange messages during the process of interaction. There is no direct connection, however, between clients and servers. A client-side program (or better called a process) sends service requests destined to the server through a software gate, called a socket. The socket is the interface point between the user’s application and the top most layer of the network system, the application layer. The application layer takes the responsibility of delivering the service request to the server. Delivering a service request is a complex job done with the aid of many layers. However, a user’s process need not worry about all of this. The end result is a clean interaction between the server and client. In client/server mode, applications intercommunicate with each other through message exchanges. To exchange messages, an application should provide the host and process addresses of the desired partner. For example, process A running at computer X that desires to send a message to process B running at computer Y, should provide the addresses for Y and B. Address of computer Y is known as Ys IP address and has a special format that we will discuss later on; process Bs address is given as a port number. Thus, if process B is a web server, then its address is port 80. Port numbers of popular applications are known to network programmers. Agents are programs that serve as an... Answer should be original and similarity (plagiarism) not more than 10% this is very important point. Answer should be at least 550 words. (References not including). Answer should be references on Harvard style (Not use Wikipedia) should be Academic Articles or books or Trusted website. When use citation from any reference please keep it between "citation" (Author,Year). As reference you can use the following book: Jim Kurose & Keith Ross (2010), COMPUTER NETWORKING: A Top-Down Approach. 5th ed. Boston: Addison Wesley. Assignment is: Discuss the Apache Web server in regard to cost, functionality, and compatibility. Are there certain implementations were it may not be suitable?