What is Protocol and Type of Protocol in Computer Network - rlmdtechnical

What is Protocol:

A protocol is a set of rules that control the communication between computers on a network. These rules include guidelines which maintain the following features of the network. Such as - the mode of reception (mode of access), allowing physical topology, controlling the type of cabling and transferring data, etc.

   

Major Common Protocols:

1. Ethernet protocol

2. Local talk

3. Token Ring

4. FDDI

5. ATM

Ethernet Protocol:

The Ethernet protocol is used extensively in far-flung areas. Ethernet uses a method of access called CSMA / CD (Carrier Sense Multiple Access / COLLISION DETECTOR). It is a type of system where every computer listens to the cable i.e. it receives information. The computer will transmit data only if the network is clean before sending any data through the network. If a node is already transmitting data over the cable, then other computers wait till the line is cleared. When many computers work together, it has happened many times that COLLISION is generated. Each computer then shuts down and waits for the line to be cleared again. This way of accessing it reduces the COLLISION.

The Ethernet protocol maintains three types of topology, linear bus, star and tree. Data can be transmitted over a wireless access point twisted pair, coaxial or fiber optics cable at speeds of 10 mbps to 1000 mbps.

Ethernet Frame:

       

Ethernet 802.3 Packet Format:

Fast ethernet

To speed up the transmission speed, the Ethernet protocol developed a new standard that has a capacity of 100 Mbps. Generally, it is called Fast Ethernet. Fast Ethernet uses various more expensive network connectors and network interface cards. In addition, a list of 5 pairs of papers requires fiber optical cable. Fast Ethernet is commonly found in schools nowadays.

Gigabit Ethernet

A new protocol has been developed in the development of the Ethernet standard, which has a transmission capacity of 1gbps. Giga bit ethernet is currently used for backbone on the network. In future it will probably be used for work station and server connections. It can be used with both optical fiber cable in and copper. 1000 base Px copper cable is used for Gigabyte Ethernet. It is said that the standard form of this film was ready in Standard 1999.

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Benefits and Drawback of Setting up a Network - rlmdtechnical

               Benefits of setting up a network:

     

                    

Speed

The network performs the task of transferring and splitting files at very high speed. The files witout network is copied and shared in a floppy disk and then this disk is sent from one computer to another. This method of transferring is known as Sneakernet which takes much longer.

Price

Network versions of many popular software programs are available at the right price. While its price is better than the license copy individually. In addition to saving money, sharing the program on the network works to upgrade the program soon. All these changes are made once. Everyone on the file server instead of being at work stations.

Security

Files and programs are designed on the network as a copy inherit. So that you do not have to worry about illegal copying of programs. With this, a password can be established for the Directory. So that it can reach only the authorized user, that is, practically the right user.

Central software manager

The biggest advantage of setting up a network is that the specialty in schools is that all software is loaded on a single computer. This energy sort that takes time and restores the problem of restoring and covering all the computers of the entire building.

Sharing resource

Sharing resource is another area in which network is ahead of independent computer. Most schools cannot afford the cost of laser printers, in addition, it is expensive to add fax machine computer modem screener and CD ROM players to each computer. But whenever these or similar devices are joined together in a network, then they are shared by many users.

Electronic mail

Network presence provides the necessary hardware to install email. Email provides communication facilities to schools, both personally and professionally. Through this facility, even the smallest common information reaches the school staff. The electronic mail on the LAN connects the students to their teachers through communication facility and through this they can also see their schools. If the LAN is connected to the Internet, students can get information about the whole world outside of school.

Flexible access

The school network provides the facility for students to access and work on their files from inside and outside the school. And the public works of the network, the students can complete the tasks assigned to them in the classroom itself and also provide the facility of safe keeping and work in the public reception area of ​​the network, then those students finish their school work After that go to the media center. Through the network, students do their work jointly.

Work group computering

Workgroup software such as Microsoft back-office allows many workers to work on the same robbery or to perform a task with consent. For example, in different schools, which are in one country, they are provided with different documents or spreadsheets, the same syllabus according to different standards, together with the learners.

       Disadvantages of setting up a network:

1. It is expensive to install though the network saves most time and money. There is an intrinsic cost to install it, but cable network cards and software are expensive and should be installed by a technician.

2. Manager work requires time to properly repair a network, and needs experts, and many schools employ networks only to find they have administrative support. There is no budget.

3. Server files may fail. Although a file server is not expected to fail than a computer. When the file server is idle then the work of the entire network stops.

4. Cables can break Topology contains many types of information for the design of cables. For the inconvenience of the broken only, some of it reduces its size by changing it. On making other changes, a broken can only shut down the entire network.

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Computer Networks and Its Types - rlmdtechnical

Computer Network

A network consists of two or four computers that are connected in a series by various means (such as printers and CD ROMS). They are connected like changing FILES or means of electrical communication. Telephone lines, radio rays are connected through satellites and illuminated rays etc. via cable on computer network.

    

There are basically three types of networks.

1. Local Area Network (LAN).

2. Wide Area Network (WAN).

3. Metropolitan Area Network (MAN)

 Local Area Network

A local area network LAN is a network that connects small areas. It is generally limited to a geographical area. Such as a writing lab school or building. Rarely LAN computers have a network of more than 1 mile.

In a particular type of LAN network, a computer is used as a file server, it stores all the software that controls the network. A computer connected to a file server is called a work station. These work stations are less powerful than file servers, and they also keep additional software on their hard drives. Only used for connecting networks on the main LAN. A computer has interfere cards. For more information on LAN networks, the process of connecting to it is done by topology cabling and hardware sector

Wide Area Network

Wide area networks connect slightly larger geographic areas such as Florida and the United States or the entire world DEDICATED TRANSOCEANIC or this type of network is used to connect satellite uplinks. WAN uses telecommunications from Florida to Tokyo within minutes. Without paying long telephone bills. WAN is complex. They use multiplexes to connect local and metropolitan networks like the Global Communication Network to the Internet.

Metropolitan Area Network

A metropolitan area network (MAN) is a network that connects users of a geographic area or a large area larger than a local area network (LAN) but smaller than a Wide Area Network (WAN) with computer resources.

A large computer network spread over a city or large university campus is called the Metropolitan Area Network or MAN. The purpose of MAN (Metropolitan Area Network) is to provide links to the Internet over a long period of time. A MAN (metropolitan area network) can usually consist of multiple LANs to form a network. This large network MAN (Metropolitan Area Network) now consists of optical fiber set-up.

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Synchronous and Asynchronous Transmission - rlmdtechnical

     

                 

  Synchronous and Asynchronous Transmission:

Data transmission by either medium is either asynchronous or synchronous. Asynchronous transmissions are typed with the keyboard as it is. Data character by character is transmitted. Therefore, the distance between the center is the distance. However, it is cheap to implement because it does not have to be secured before sending data. In the synchronous mode on the other hand, secure data is transmitted by one block. There are many factors in each block. It is suitable for remote communication, for example: card reader and printer, among computers and related devices.

The main communication device to be used today:

1. Wire pairs: These are commonly used in local telephone communication and for short-range digital data communication it is made of copper and twisted pair. The speed of data transmission is usually 9600 bits per second at a distance of 100 meters.

2. Coaxial Cable: This is a group of specially wrapped insulated wire which transfers data at a higher speed. They are made of central copper wires around which insulation happens and the copper network is located on it. It is used for a long-distance telephone line and local area network, because it has the ability to transfer data with sound resistance and faster speed.

3. Microwave: This is the use of high frequency radio signals for data transfer by space. The transmitter and receiver of the microwave system should be in line-of-sight because the radio signals are not bend. There is no facility of long-distance transmission by the microwave. Repeaters are used in the distance between 25 to 30 kilometers of transmitting and receiving end to remove the line of site problem and the power amplification of weak signals.

4. Communication Satellite: The problem of line of site and repeaters is overcome by satellite, which is today the most used data transmission medium. Communication is a microwave relay station located in satellite outer space. INSAT-B is the same type of satellite which is accessible from anywhere in India. In satellite communication, microwave signals are sent to the satellite located in the space by the transmitter located on the earth. The satellite amplifies a weak signal and translates the receiver back. Its main advantage is that it is the only microwave station visible from any point in the larger area. The data transmission rate in the microwave is 16 gigabytes per second. These are mostly used to link big cities.

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Data Transmission Modes in Computer Network - rlmdtechnical

                                        Data Transmission Modes in Computer Network

Data Transmission Modes:

There are 3 ways to transmit data from one point to the other.

1. Simplex: Communication can be in one direction in this mode, receivers receive single from transmitting device. In this way the flow of information is unidirectional, it is used very little for data communication.

                  

2. Half-duplex: In this mode the communication channel is used in both directions, but data transfer can be done in only one direction at a time. Hence the half-duplex line can alternately send and receive data.

3. Full duplex: In this mode, communication channels are used in both directions at one time. Using the full duplex line increases the capability because the required line turnaround time in the half-duplex system is overcome. The example is a telephone line.

Digital and Analog Transmission:

Data transmits from 1 point to electrical signals, which are digital or analog. Therefore, it is necessary to know the difference between analog and digital. An analog signal changes in the continuous range between power, sound, light and radio waves. On the other hand, digital signal accepts only discreditable set of values ​​in the given range. Examples are computer and computer related tools. Analog signal is measured in volts and its frequency is in hertz. Digital signal is the order of the voltage displayed in the binary form. When digital data is sent to analog medium, then the digital signal is converted to analog. The technique to convert digital signals into analog is called modulation.

Conversely, conversion to analog to digital is called demodulation. The device that is analog and digital to the digital is called modem.

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Data Communication System in Computer Network - rlmdtechnical

                 Data Communication System in computer network

       

Introduction
Today the computer is available in many offices and homes, and hence the need to share data and programs between different computer users with the promotion of data communication facility. The communication between computers has increased so that it brings the computer power out of the computer room. Today, sitting in one place can contact the computer located on a remote site through the Communication channel is there.

Data communication

In everyday life, we use some kind of communication medium. For the communication of information and messages we use telephone and postal communication systems. Similarly, data and information communication from one system to another may also be transmitted outside the geographical area. Data transmission is the dissemination of information by using some standard rules. These methods include communication of electrical signals through conductor, optical fiber and communication of optical signal by electromagnetic field.

Assume that the manager has to write some letters to all his clients. To prepare a letter, first he will have to use his PC and word processing package. If all clients are connected to PC through PC networking, then data and information, computer files and other programs are transmitted from one computer system to another in a few seconds. New forms of communication such as email and internet are only due to computer networking.

The main elements of the communication system:

The following are some of the main requirements for the functioning of any communication system-

1. A sender who prepares the message to be transmitted.

2. Message carrying medium.

3. A receiver who receives the message.

In the data communication, 4 words are mainly used in the work.

1. Data: A group of raw data that takes the form of information after processing.

2. Signal: Electrical electromagnetic encoding of data.

3. Signaling: Signaling on the communication medium.

4. Transmission: Communication of data received by signal processing.

Communication links.

The answer is Data Communication Software. This is software which facilitates interaction with other systems. Data Communication Software directs computer systems and devices to transfer data from one place to another. The method of data transformation in the form of software is called protocol.

Data transmission software or protocols do the following for transmission error-free transmission.

1. Data Sequencing: The long message to be transmitted is broken into small packets, so that the data transmission error is free.

2. Data routing: Before sending this data, the process of finding the most suitable route between the source and the destination is processed.

3.flow control: All machines in the context of motion do not have the same capability. Hence, the control of dataflow, the process of sending data between the fast sender and the slow receiver.

4. Error Control: There are two main functions of error detection and error recovery communication software to see that the data is transmitted without error.

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