The IP manages the addressing of the data packets, and is responsible for adding the sender and receiver IP addresses to each packet, as well as determining which data packets are addressed for that machine. It works alongside the TCP protocol to ensure that data is sent securely across the internet. By accepting these Product Terms, you agree that the Federal Arbitration Act , including its procedural provisions, governs the interpretation and enforcement of this provision. This means that the FAA governs, among other things, the interpretation and enforcement of this provision requiring mandatory arbitration, including the class action waiver discussed below. State arbitration laws do not govern this provision in any respect.

In this lesson, learners will look at how networking protocols are used to ensure that clients can communicate and share information across computer networks. They will then learn about some key networking protocols that are used for much of the communication across the internet. Finally, learners will work together in small groups to design their own networking protocol to meet a set of objectives and to try to overcome a number of restrictions. This layer sets up the communication between the two hosts and they agree settings such as ‘language’ and size of packets. This is where the network applications, such as web browsers or email programs, operate. It is also where the transfer and email protocols operate.


We may however enter a web address / URL using a domain name such as A layer can hence be defined as being a sub-group of protocols needed in a network communication. All the protocols used on a TCP/IP network have been categorised/grouped into 4 abstract layers called the TCP Stack.

  • It doesn’t keep track of what it has sent so it can resend if necessary.About all that UDP provides is port numbers, so that several programs can use UDP at once.
  • IP (the “internet protocol”) is responsible for routing individual datagrams.
  • UDP is designed for applications where you don’t need to put sequences of datagrams together.
  • ICMP is used for error messages, and other messages intended for the TCP/IP software itself, rather than any particular user program.

The protocol defines the specific set of responses that can be sent as answers to any given command. However programs that don’t want to analyze them in detail can just look at the first digit. In general, responses that begin with a 2 indicate success. Those that begin with 3 indicate that some further action is needed, as shown above.

The importance of protocols and standards

Furthermore, every host implementation of TCP/IP must be prepared to accept pieces and put them back together. The most common alternative is UDP (“user datagram protocol”). UDP is designed for applications where you don’t need to put sequences of datagrams together.

IP Routing

Every session must begin with a HELO, which gives the name of the system that initiated the connection. (There can be more than one RCPT command, if there are several recipients.) Finally the data itself is sent. Note that the text of the message is terminated by a line containing just a period. (If such a line appears in the message, the period is doubled.) After the message is accepted, the sender can send another message, or terminate the session as in the example above.Generally, there is a pattern to the response numbers.

A Wide Area Network is a network that covers a large geographical area. The internet is a prime example of this type of network. Quite a number of Wide Area networks are built by Internet service providers and are sold to people and companies via subscriptions. At each end of the leased line, a router connects to the LAN on one side and a hub within the WAN on the other. SMTP is used by mail servers to send and receive mail from all other mail servers around the world. FTP is the protocol used to upload or download (i.e. transfer) files between computers and the internet.