Repeater

Repeater

     In communication system, transmission media is used for transmitting information between communicating entities. Mostly cables are used as transmission media. While moving data through, the signal become weak after specific distance, this referred as attenuation. To address this problem, the signal needs to get boosted when they become weak, so to do this repeater is used. 

    

       Repeater is the networking device which operates at physical layer of OSI reference model. 

     A repeater is the network device which receives signals before it becomes weak, amplifies signal and sent to other end.

        Repeaters removes the unwanted noise in an incoming signal. Repeater regenerates weak signals into original bit patterns.

        Repeater is used to extend the length of LAN, by connecting two segments of single LAN. Repeater cannot connect LANs of different protocol.

         Repeater don't have packet filtering capability.

Hub

  Hub is the networking device which contains multiple, independent port that match the cable type. Hubs are used to connect computers together in star topology. Hub is basically a multiport repeater. In many cases, the difference between the two devices (hub and repeater) is the number of ports that each provides. 

     Hub works at physical layer of OSI reference model. At physical layer unit of data is bit, means hub handles data in the form of bits. So hub is unaware about what kind of data is there and to whom it should be transmitted. Hub have no intelligence. 

     Hub converts the computer network topology from a linear bus, to a star topology. When data arrives over the cables to a hub port is electrically repeated on all the other ports connected to the same network segment, except for the port on which the data was sent. Hub is the broadcasting device which means it sends incoming data on specific port to all remaining ports. So the devices attached to a hub receive all traffic traveling through the hub.

     The more devices there are attached to the hub, the more likely there will be chances of collisions. A collision occurs when two or more workstations send data over the network wire at the same time. 

     Hubs come in three basic types: 

Passive –  A passive hub is used only to share the physical media. It does not need electrical power.
 

Active – An active hub must be plugged into an electrical outlet because it needs power to amplify the incoming signal before passing it out to the other ports.
 

Intelligent – Intelligent hubs are sometimes called smart hubs. These devices basically function as active hubs, but also include a microprocessor chip and diagnostic capabilities.

Peer to Peer Network Relationship

In Peer to Peer network relationship all the network computers are of same configuration. These number of computers are connected to each other to facilitate network. 

Each computer contains its own resources and data. It means resources (file, folder, printer) are distributed among peers (computers).

Each computer in this network relationship is responsible for sharing resources available on it, for making accessible for other.

Each computer is also responsible for accessing resources available on the other computers. when a peer (computer) accessing the resources from other peer, then the resource accessing peer works as client and resource provider works as server. 

The peer to peer network relationship is the one in which each computer can perform the task of client as well as server.

In this relationship processing is done in distributed form (decentralized). Here data is stored on different/ separate system so it is very difficult to take backup. 

In peer to peer network relationship there is no need of server based operating system or Network Operating System (NOS). It does not require administration because its job of individual user is to making available the resources to other as well as maintaining the system. This network relationship is having very low security.

This is suitable for small network, where no need of centralized processing, no need of backups, security is not required.

Client Server Network Relationship

In client server network relationship two types of computer system present that are clients and servers. Server is a more powerful computer system whose configuration is high than client. Client is a normal computer system or having low power than servers.

 The server contains data, information, and all resources. All the clients are connected to the server. The communication in between client and server is in the form of request and response scenario. Whenever a client need resources (information, data, or any other resource), client simply sends request to the server. server takes these request process and respond the client with required services (acknowledgment). 

The job of server is provide service to the requesting clients. And job of the client is to request server whenever it requires resources or service. Here client is a requester or service user and Server is the service provider.

 

In client server network all the data is stored on server and all the resources are located at server. In this type of network we need a special operating system on server for managing all clients, this operating system is called as server operating system or Network Operating System (NOS). The client needs just a client operating system. 

The client server network is the one in which centralized processing. Security is high in client server network because all the resources and data is stored on the centralized node (i.e. server). Client server network is easy to manage because all the management of software is done at server. 

It is easy to take backup in client server network relationship.