Network Protocols

Most IP experts recommend that individual computers should not try to keep track of the entire network. Instead, they should start with default gateways, and let the gateways tell them the routes, as just described. However this doesn’t say how the gateways should find out about the routes.The gateways can’t depend upon this strategy.

Every network utility has to be able to make such queries, since this is now the official way to evaluate host names. Generally utilities will talk to a server on their own system. This server will take care of contacting the other servers for them. This keeps down the amount of code that has to be in each application program. The domain system is particularly important for handling computer mail. There are entry types to define what computer handles mail for a given name, to specify where an individual is to receive mail, and to define mailing lists.

  • Now many installations have several kinds of computers, including microcomputers, workstations, minicomputers, and mainframes.
  • These Product Terms will be governed by the substantive internal laws of the State of California law, without reference to conflict of laws principles.
  • The current versions can be found on /legal or by contacting Belkin Support.
  • A program can ask for a specific piece of information, or all information about a given name.
  • Those that begin with 3 indicate that some further action is needed, as shown above.

It also makes sure that the data arrives, resending datagrams where necessary. But for a question that fits in a single datagram, we don’t need all the complexity of TCP to do this. If we don’t get an answer after a few seconds, we can just ask again. For applications like this, there are alternatives to TCP.

The importance of protocols and standards

Ethernet is a family of related protocols which deal with how data is sent along ethernet cables – it isn’t a single protocol. There are lots of parts to the ethernet protocol family, which include how the hardware is managed, as well as how data is sent and received and how data collisions are managed. When we use our web browser to access a web page, it is very unlikely that we know the IP address of the web-server hosting the required web page.

Since they are both doing file transfers, one end of the connection involves the well-known port number for FTP. The only thing that differs is the port number for the program that the users are running. Generally, at least one end of the connection asks the network software to assign it a port number that is guaranteed to be unique. Normally, it’s the user’s end, since the server has to use a well-known number.

It is also possible to use the domain system to store information about users, mailing lists, or other objects. Remote terminal connections use another mechanism still. When it is necessary to send a command (e.g. to set the terminal type or to change some mode), a special character is used to indicate that the next character is a command. If the user happens to type that special character as data, two of them are sent. This thesis analyses the evolution of British computer networks and the Internet between the years 1970 and 1995.

We aim to help you reflect on your own learning and help you feel more clear about your progress through clarifying what is expected of you in both formative and summative assessments. This module introduces the fundamental concepts of different Internet and LAN protocols that developed for computer networks. Please be aware that resources have been published on the website in the form that they were originally supplied. This means that procedures reflect general practice and standards applicable at the time resources were produced and cannot be assumed to be acceptable today. A network protocol is an agreed way of communicating over a network.


TCP (the “transmission control protocol”) is responsible for breaking up the message into datagrams, reassembling them at the other end, resending anything that gets lost, and putting things back in the right order. IP (the “internet protocol”) is responsible for routing individual datagrams. However in the Internet, simply getting a datagram to its destination can be a complex job. Keeping track of the routes to all of the destinations and handling incompatibilities among different transport media turns out to be a complex job.

1 Computer Networks

The numbers allow the user program to respond unambiguously. The rest of the response is text, which is normally for use by any human who may be watching or looking at a log. In this case, the mail server could get the information by looking at the message itself.

– The datagram is checked for corruption and the correct address. – If all is ok the Network Access Layer extracts the data and passes it to the designated protocol. Wikipedia articles on the Internet, packet switching and IP addresses. How many control bits will be used to control data transfer. This section provides general and specific information pertaining to networking, including an overview of network concepts and detailed discussion of popular network protocols. Another advantage of TCP/IP is that the IP packets don’t have to be sent to the same type of server.