Question

List at least six protocols used on the Internet and briefly describe what each of them are used for.

Answer 1

Internet Protocol: our languages very different from the language the computer uses. So the messages we create need to be translated from an alphabetical text into an electronic signal before they can be sent. This translation is handled in the computer by the separate modules in the communication protocol. Because these protocols are rules of conduct usually communicate two or more modules they are best described as layers in a stack of protocols.

These layers are:

1. Application layer
2. Transport layer
3. Internet layer
4. The link layer
5. Physical layer.

The messages that we send are filtered through these layers and Brocken down into small chunks of data called packets.

Example: message from the application layer HTTP (Hyper Text Transfer Protocol). The transport layer uses the TCP (Transmission control Protocol) to encapsulate the data blocks from the application layer and then moves to the internet Protocol (IP) layer is used to deliver the packets. These packets are delivered through the link layer which is in Ethernet cable to physical layer which is the basic hardware of your computer network. The computer that receives these data packets moves them through protocols stack in a reverse order. So that the message re constructed and understood.

DHCP: (Dynamic Host Configuration Protocol)

It is an application layer protocol used by hosts for obtaining network setup information such a ip addresses, subnet mask, default gateways and some other information.

A user trying to obtain an ip address so, he can connect to the internet when computer first time on automatically setup request looking for a DHCP server. Once the DHCP server responsible for sent the ip address information the system automatically configure the computer so that can connect to the network. In this a router will be used in between your computer system and the DHCP server.

FTP: (File Transfer Protocol)

The browser is a client which sends requests and the request goes to the webserver and goes in port 80. The request may ask for something called a webpage. The FTP server makes a copy and sends it back to the client

SMTP: (Simple Mail Transfer Protocol)

Here POP and IMAP protocol that allow you to retrieve email from the mail server SMTP is the protocol that allows you to send email to mail server. Specifically the SMTP protocol is used to send email from email client to your email providers email server and to send email between two email servers on the internet.

UDP: (User Datagram Protocol)

UDP is a connection less protocol that means no session is setup during the transmission. UDP is unreliable this means messages are transmitted without sequence numbers and without acknowledgement. UDP messages are transmitted at regular intervals or after determined time limiter has been accessed. UDP does however allow the authentication of the application layer protocol which is to receive the data since UDP is unsophisticated protocol it occupies only little memory and process resources. UDP based application layer protocols only require un acknowledgment data transfer.

ICMP: (Internet Control Message Protocol)

While ip takes care of imputing between networks ICMP send an error and control messages of the protocol. ICMP doesn’t make IP reliable protocol. It might rise to report errors messages on the certain circumcision to give feed back. ICMP messages are transported in IP datagrams and therefore not reliable. When host transmitted datagrams to another host at a certain data rate which fully occupied to the capacity. The ICMP source quench message to slow down the router transmission speed.

ISDN: (Integrated Service Digital Network)

It is a set of standards for digital transmission over ordinary telephone copper wire as well as over other media.

ISDN in concept is the integration of both analog or voice data together with digital data over the same network.

They are two types:

1. Basic Rate interface (BRI), intended for the home and small enterprise.
2. Primary Rate Interface (PRI), for larger users.

Both rates include a number of B-channels and a D-channel. Each B-channel carries data, voice and other services and each D-channel carries control and signaling information