Tag: Socket Programming

You can take this quiz online at http://www.net-intro.com/quiz/ Which layer is right below the Application layer? a) Transport b) Internetworking c) Link Layer d) Obtuse layer What kind of document is used to describe widely used Application layer protocols?86 a) DHCP b) RFC c) APPDOC d) ISO 9000 Which of these is an idea that…

HTML: HyperText Markup Language. A textual format that marks up text using tags surrounded by less-than and greater-than characters. Example HTML looks like: <p> This is <strong>nice</strong></p> HTTP: HyperText Transport Protocol. An Application layer protocol that allows web browsers to retrieve web documents from web servers. IMAP: Internet Message Access Protocol. A protocol that allows…

The entire purpose of the lower three layers (Transport, Internetwork, and Link) is to make it so that applications running in the Application layer can focus the application problem that needs to be solved and leave virtually all of the complexity of moving data across a network to be handled by the lower layers of…

The applications which send and receive data over the network are written in one or more programming languages. Many programming languages have libraries of code that make it quite simple to write application code to send and receive data across the network. With a good programming library, making a connection to an application running on…

When we looked at the Transport layer, we talked about the “window size”, which was the amount of data that the Transport layer on the sending computer will send before pausing to wait for an acknowledgement. In this figure, we see a message broken into packets, with some of the packets sent and acknowledged. Six…

The HTTP protocol is only one of many client/server application protocols used on the Internet. Another common protocol is used so that a mail application running on your computer can retrieve mail from a central server. Since your personal computer might not be turned on at all times, when mail is sent to you it…

In this section we will manually exercise the HTTP protocol by pretending to be a web browser and sending HTTP commands to a web server to retrieve data. To play with the HTTP protocol, we will use one of the earliest Internet applications ever built. The “telnet” application was first developed in 1968, and was…

Just like people talking on telephones, each pair of network applications needs a set of rules that govern the conversation. In most cultures, when your phone rings and you pick up the phone you say “Hello”. Normally the person who made the call (the client person) is silent until the person who picked up the…

It is important to remember that two parts are required for a networked application to function. The architecture for a networked application is called “client/server”. The server portion of the application runs somewhere on the Internet and has the information that users want to view or interact with. The client portion of the application makes…

We have been working from the bottom to the top of our fourlayer TCP/IP network model and we are finally at the top. The Application layer is where the networked software like web browsers, mail programs, video players, or networked video players operate. We as users interact with these applications and the applications interact with…