12 Explain the function of common networking protocols

Protocols: Computers needed to be connected for the purposes of sharing files and devices like printers etc. To make this haring possible along with a length of cable was required a method which could ensure this communication and sharing. Protocols are that particular method. There are a number of protocols that are used with their own features and set of rules. The choice of which protocol to implement depends on the final objective that has to be achieved.

Protocol Suite: Combination of protocols is termed as protocol suites. It has an all encompassing set of protocols allowing the devices to establish communication amongst them.

There are three main kinds of protocols:

- Application Protocols: These provide client functionality;

- Transport Protocols: These provide mechanisms for moving data around the network;

- Network Protocols: These provide the underlying tasks enabling the movement of data.

TCP/IP (Transmission Control Protocol/Internet Protocol): It is the most commonly used protocol in today's networks. It is a comprehensive protocol suite available for nearly all platforms like Windows, Linux, UNIX, and Novell systems to name a few. The protocol has experienced competition from Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX), AppleTalk and NetBIOS.

The role played by protocols is important to understand how protocols facilitate communication. Information passing through networks passes through certain steps at both the receiving and sending end. The process can be discussed as:

Protocols from the Sending Device:

The general steps that a computer sending data must perform are:

1. Break the data into smaller parts. These smaller portions of data are called packets.

2. Attach the network address information. This address is used to identify the destination for the packet and also the route the same is going to travel.

3. Prepare the data for transmission. Once the data is prepared it is sent through the network interface card (NIC) to the network.

Protocols on the Receiving Device:

The steps at this end of the network occur in the opposite order. The general steps that a computer receiving data must perform are:

1. The data is taken off the network media.

2. The addressing information is separated from the packets.

3. Reassembling of the data packets.

4. Sending the packets to the specific applications

The prerequisite to for accomplishing the steps effectively is to follow the same protocol at both the ends. In case two devices with different protocols are required to communicate, the same is only possible if a gateway is a part of the network.