Protocol is basically a set of rules that are formed for the computer of networks for establishing proper communication among them. To establish a proper communication network, many protocols are used Few commonly used protocols are described below.
TCP IP is basically an Internet Protocol suite, comprising of two basic protocols i.e. TCP and IP.
TCP is acronym of Transmission Control Protocol. This protocol is basically responsible for breaking the message into smaller packets before they are transmitted on the medium.
At receiver’s end, it reassembles the packets into corrects sequence to get back the message in complete and original form. The functioning of TCP protocol is illustrated in the given figure:
Note that transmitting shorter messages (instead of long messages) becomes easy in network . This makes the communications more efficient. Various packets can be routed through different routes at a particular time a particular line is not available.
Due to different routes, undertaken, packets may not arrive the destination in sequence. Thus proper sequencing and assembling of the packet is done. As shown in the figure, this activity is performed by TCP protocol.
IP is acronym of Internet Protocol. It mainly deals with addressing issues of the packets and few other aspects.
It adds addresses of the sender and receiver in all the packets. It also adds Time To Live (TTL) in cache packet .As the packet travels over network this time decrements. Packet is discarded when it becomes zero. It prevents packets from wandering in the network forever and making congestion in network. The functioning of IP is illustrated in the figure PM,
IPX SPX is short form of Inter network Packet Exchange/Sequential Packet Exchange. It is a network protocol, which was developed by Novell Corporation for its Novell Netware operating system but now it is being used freely for other environments also.
It is basically transport layer protocol. The SPX layer sits on top of IPX layer and provides connection-oriented service between two computers of the network SPX is mainly used in client server applications, SPX/IPX protocol is similar to TCP/IP protocol. SPX performs all those functions, which TCP performs and IPX perform all these functions, which IP performs.
NetBIOS Extended User Interface is an unrouted network protocol. Routing is basically selecting a path from many paths that remain available for communication Unrouting means, where no multiple choices of path are available. Since it is unrouted protocol hence it can only be used for communicating with the devices on same network segment.
It is transport layer protocol. It was developed by Sytek company for IBM. It provides following three main services:
- Name service for name registration and resolution.
- Session service for connection oriented communication.
3 Datagram distribution service for connectionless communication.
FTP is short form of file transfer protocol. It is mainly used for transfer of files over network that uses TCP IP protocol. It basically comprises of two main components, called FTP server and FTP client FTP server monitor the network to find out if there is any request from a computer to establish a session Other component, FTP client. sends request to FTP server to establish connection. Once the connection is established. FTP client can perform file activities of following types:
1.Uploading the file to the server.
2 Downloading a file from the server.
- Renaming an existing file on the server.
- Deleting the file on the server
As mentioned earlier. FTP is application layer protocol hence it allows all file activities, irrespective of the operating systems being used on both the computers.
Telnet is a protocol, which is used for accessing remote computers.Using telnet a person can access another computer remotely. Note that FTP allows a user to manipulate files onother computer, but Telnet allows a user to log-on to another computer as a user by supplying correct login name and password. Thus he can use applications and other resources, present on that computer, as per permissions granted to him.
In this protocol communications is established, using TCP/IP protocol and the communication is based on a set of facilities know as Network Virtual Terminal (NVT).