2.  The devices which each intercorrect several computer or different to each other, each nones network devices.  There are various types of Network devices. 1. Repeater 2. Hub 3. Switch 4. Bridge 5. Router 6. Gateway 7. CSU/DSU 8. Modem 9. NIC (Network Interface Card)

3.  Repeater is a simple Hardware devices that moves all packets from one LAN Sigement to another by regenerating & retiming the electrical signal.  The main perpose of a repeater is two extend the length of the network transmission medium beyond the normal maximuim cable length.

4.  Hub is a central devices which is used in star topology.  A hub takes in coming signal & repeats its out to all parts on a network.  Hub are also none as multiports repeater devices  The no. of ports capacity of Hub is commonly in range of 8-32 ports

5.  There are classified into two category  According to the working of Hub  Active hub and passive hub  Active Hub:-active hub usually have eight to twelve ports to connect to network computer.  The provides the function of repeater regenerating and transmitting to all of the there devices.  If required electrical power to run.  It is expensence then passive hub.  It is used for transmitting data at longer distance.  Passive Hub:-passive hub at as a connection points.  It does not regenerate the data.  The signal is passes through the hub.  It also used in star Topology.  It is used for small are home networks.  Passive hub do not required electrical power to run (like as a repeater).

6.  Switch is as N/w devices.  Switch is expensive then hub.  Switch required electrical power to run.  Switch is Basically used in LAN.  It store make address of each computer which is connected to each.  It works on Layer2 Layer 3 (data link layer & Network Layer)  There are various type of switches  (1.)Lan Switch (2.) WAN switch (3.)ATM switch  LAN SWITCH:-lan switch provide a seprate conection for is node in a company internal network are none as lan switches.  Lan switch is interconnectes 10 mbps & 100 Mbps Ethernet segments.  Lan switch is used in LAN Architecture.  LAN switch deside to propare path of data packets.

7.  Wan switch is used in WAN architecure to connect the node with large distances.  It works on the principal of OSI model  Wan switch is a multiport internetworking.  Router is used in wan switch Network. WAN SWITCH LAN SWITCH

8.  It stand for Asychronous Transfer Mode  ATM switch support voice, Video and data application for transmit etc.  ATM switch is connected with OFC(fiber optics cable) with each other.  ATM is used is cell oriented technology  ATM is high performance devices.  ATM switch used 53 bit data packet.

9.  Bridge are connecting device to connect two LAN.  It works on layer 2 (Data Link)  Bridge can only be connected to similar N/W sigement.  The bridge has only two ports when bridge received any data, it check the sources and destination address. It both address are same site, bridge does not allow to cross over the data to another site but if the address are different then the port of bridge allow the data to cross over it.  The bridge filter control the n/w traffic with connecting the segment of network.

10.  Transparent Bridge:- this bridge is generally used for Ethernet n/w and is very easy to install. It used the make address for transmet the data. It can be used for broadcast and multicast networking.  Translational Bridge:-the bridge is designed to convert one n/w system to another n/w system. it used to connect two different topology or n/w, such as bus topology and ring topology.  Source route Bridge:- it is used for large n/w.  It is used in WAN network.  It provides route for a data packet to be transmit and proper delivery of data.

11.  Router is internetworking devices.  Router is used to connect two different n/w.  Router is operate is the layer three (n/w layer) of OSI reference model.  Router received the data from one n/w and send to the other n/w.  Router pass the information or data only if the n/w address is none.

12.  Gateway is a process which is used to connect to desimilar n/w working on different platform such as n/w of windows opearting system platform with n/w of Linux operating system based platform.  It works on all layer of OSI Model.

13.  It stand for network interface card.  It is also none as Ethernet.  It works on Layer 1(physical Layer).  It is Basically used in LAN.  It is a physical device used in physical topology.  The main function NIC(adapter) is to allow a computer to connect to a LAN transmit or share the data.

14.  It stands for channel service unit/digital service unit.  It also works on layer 1(physical layer)  DSU also none as service unit.  It is most like as a NIC Card.  CSU/DSU is a device which is used to connect one pc to another pc.

15.  Modem is a devices that converts the digital signal to analog signal and analog to digital.  Modem stands for modulator and demodulator.  modem speed is measured in bps, different transmission speed of modem are 9600 bps, 14400 bps, 28800 bps, 36600 bps,56900 bps.  According to the working of modem is classified into two category.  Internal modem  External modem  Internal modem:- a modem that plugs into the expention plug of a pc or into the pc connector of a laptop.  External modem:- external modem can be used with different computer at with different time.

16.  It is a devices which is used I wireless communication. it is used in sallular telephone, cordless phone etc.  Transceiver :- it is a devices which is used in wireless communication.  It is used in salluler telephone, cordless phone etc.  Transceiver mains transmite and receiver,  Transciever is classified into varrias category the are  (1) Simplex (2) Half Duplex (3) Full Duplex  Simplex:- simplex of a form commmunication in which signals are sent is only one directions.  Ex:- Radio  Hulf Duplex:- Hulf Duplex of a form of communication in which signals can be sent or Received, but not both at the same time.  Full Duplex :- full duplex of a form of communication in which both station, sent and received at the same time and to communication channel are required.  Ex:- phone