Networking Devices

Networking Devices.

                        Networking Devices:-

1.  Router:-

·      It is a device of layer 3(net     work layer)inOSI model.

·    It is a device which makes communication possible between two or more different network present in different geographical location.

·      It maintains the routing table.

· It is a specialized computer connected to more than one network.so it is also called a internetworking devices.

NOTE:-
ü internetworking device mean network of network.In simply a device connects a two or more than two networks are called a internetworking device

·      Having software that allows the router to move data from one network to another network.

·      It perform many functions:-

-        To connect networks together.

-        Broadcast traffic under control.

·      Several companies that make routers:-

-CISCO

-NORTEL

-3 COM

-HP

-JUNIPER

2.  Switch:-

·      It is a device of data link layer(layer 2)in OSI model.

·      It is a networking device that connects network segment or network devices.

·      It is also called a Multi-port network bridge because it is a improvement device of bridge.

·      Switches that additionally process data at the network layer & above are often to referred to as layer-3 devices or multilayer switches.

·      Receives message from any devices connected to it & then transmits the message only to that device for which the message was meant.

·      More intelligent device than a hub (which receives a message & then transmit it to all the other devices on its network).

·      Integral part in most modern Ethernet local area network(LANS).

·      Mid-to-large sized LANS contain a number of link managed switches.

·      Small office/home office applications typically use a single switch.

·      An Ethernet switch creates a separate collision domain for each switch port.

·      It provide some benefits they are:-

-high speed data exchange.

-full-duplex communication.

-low latency.

-dedicated communication between devices.         

3.  Bridge :- 

·      It is also a layer 2 (data link layer) device.

·      It is a device that separates two or more network segments within one logical network(e.g. a single IP-subnet).

·      This device is used with local area network(LAN) for extending their reach to cover larger physical area.

·      It works on both cable & radio.

·      It is usually placed between two separate group of computers that talk with each other, but not that much with the computers in the other group.

·      It has a low port density.

·      Filters data traffic at a network boundary.

·      It reduce the amount of traffic on a LAN by dividing it into two segments.

4.  NIC:-

·      NIC stands for network interface card.it is also called a LANcard.

·      It is also a layer 2 (data link layer) device.

·      It is a circuit board that is installed in a computer so that can be connected to a network.

·      It translates the data produced by the computer into a format that can be transmitted over the local network.

·      It received data packet from network layer.

·      They are responsible for developing a physical connection between the network & the computer.

·      Computer data is translate into electrical signals send to the network via NIC.

·      They can also manage some important data-conversion function.

5.  Repeater :-

·      It is a first layer (physical layer)device.

·      A repeater is an electronic devices that receives a signal & retransmits it at a higher level & or higher power.

·      It is used to regenerate or replicate a signal.

·      Regenerate analog or digital signals distorted by transmission loss.

-regenerate means filter the signal.

·      Analog repeaters only amplify the signal.

-amplify mean impurity signal transform.

·      Digital repeater can reconstruct a signal to near its original quality.

6.  Hub:-

·      It is also a layer 1 (physical layer) device.

·      It is a device that is connect multiple Ethernet devices together.

·      The device is a form of multiport repeater.

·      Hubs repeats all the information it receives & forward it to all pc terminals attached to it.

·      This repetition of data results in unnecessary data traffic being sent to the network.

·      The data is sent in bulk without the identification of its destination.

·      It is a single broadcast single collision domain.

·      It works with shared bandwidth.

·      It is used to connect many nodes into the network & centralised device in a topology.

·      It works on half-duplex node & each port connected with a single wire.

 

7.  Modem:-

·      It is also a layer 1 (physical layer) device.

·      It is a hardware device that allows a computer to send & receive data over a telephone line or a cable or a satellite connection.

·      It converts data between analog & digital formats in real time for two-way network communication.

8.  Connector:-

·      It is a layer 1 (physical layer) device.

·      A device that terminates a segment of cabling or provides a point of entry for networking devices such as computers, switch, hub.

·      It can be distinguished according to their physical appearance & mating properties.

·      Generally in networking RJ-45 connectors & BNC connectors are used.

9.  Cable :-

·      It is a device of layer 1(physical layer).

·      It is the medium through which information usually moves from one network to another.

·      It is essentially the carrier or media through which data flows.