HUB

HUB :- Short name of Hirarical Universal Bus, it works on Physical layer of the OSI model. Basically it is a half duplex device, also some time this device is called duffer device because it doesn't have any memory for storage. It also works like repeater. Hub always does broadcasting only, This is the reason, why it has been stoped using now a days.

There is one collision domain in Hubs.

Hubs are replaced by switches. 

Hub have three major types 

1) Active Hub :- having power supply

2)  Passive Hub :- No power supply

3) Intelligent Hub :- Bother the hubs used in this type.

(Collision Domain:- Maximum numbers of devices which can send data without collision simultaneously. 

Amplifier:- It increase the strength of any network. But it doesn't remove the noise that's why it has been stop using. 

Repeater :- This device is used to regenerate the weak and end aged signals, nor it make any noise neither remove the existed noise from the actual signal.    

DEVICES IN NETWORKING , NIC CARD

NIC CARD :- Short name of Network Interface Controller is also known as Network Interface Card,Network adapter, LAN adapter and Physical Network Interface. It is a networking device which connect our computer with the computer network.

As the image tells us that there are three types of NIC Card USB NIC card, Wireless NIC card and old and normal NIC card. At NIC card there is BNC port, RJ45, SC-ST (Suscriber chanel- Straight tip) and a Antina 

STRAIGHT CABLE & CROSS CABLE

Straight Cable :- This cable is use to connect and communicate different addressing system devices.
Like :-
Switch                        to            PC
Modem, Router          to            PC
Hub                            to            PC
Modem, Router          to            Hub
These cables are designed and identify by their colour coding, so lets see the colour coding of straight cable below
White Orange                             White Orange
Orange                                        Orange
White Green                               White Green
Blue                                            Blue
White Blue                                 White Blue
Green                                          Green
White Brown                              White Brown
Brown                                         Brown

Cross cable:- This cable is used to communicate and connect same addressing system devices.
Like :-
PC                           to              PC
Modem, Router       to             PC
Hub                         to             Hub
Switch                     to             Switch
Modem                    to             Router

Now colour coding of cross cable is given below
White Orange                           Orange
Orange                                      White Orange
White Green                             Green
Blue                                          Blue
White Blue                               White Blue
Green                                        White Green
White Brown                            White Brown
Brown                                       Brown

This was all about cables or we can also say communicating medium. 

TWISTED PAIR CABLE

Twisted pair cable is a type of cable  that consist of two independently insulated wires twisted around one another. The use of two wires twisted together helps to reduce crosstalk and electromagnetic induction from external sources. There are  four pairs of wire are in a cable. This cable is invented by Alexander Graham Bell.

TYPES OF TWISTED PAIR CABLE

      Shielded Twisted Pair Cable :- As the name tells us that this is shielded means covered. Each pair of cable is covered by an additional copper braid jacket or foil wrapping. This shielding helps to protect the signals on the cable from external interference. This was used in IBM token ring networks. But this cable is expensive then Unsheilded Twisted Pair.

Speed of this cable is 1000 or 1GBps.

UNSHIELDED TWISTED PAIR CABLE:- This cable is used in many Ethernet network and in 

telephone systems. some subtypes of the cables is given below:-

Cat 1                2-4 Mbps speed

Cat 2                6-8 Mbps speed

Cat 3                10-20 Mbps speed    ETHERNET CABLES 

Cat 4                40-60 Mbps speed 

Cat 5                100 Mbps speed        FASTETHERNET CABLES 

Cat 5 e             150 Mhz speed          GIGAETHERNET CABLES

Cat 6                1000 Mbps speed                            

FIBER OPTICS CABLE

FIBER OPTIC CABLE

In Fiber Optics a technology that uses glass or plastic threads (Fiber) to transmit data. A Fiber cable consist of a bundle of glass threads, each of them is capable of transmitting messages modulates onto light waves.

As shown in the pencil diagram the cable is protected by the outer jacket it protect cable from outer problems. Coating is here to protect the core part of the cable, the core is responsible to data transfer

and receive. The data exchange is done by light in this cable.                                                               

This cable has much greater bandwidth as compare to metal cables, also carry more data then metal cable, much thinner and lighter. Data can be transmitted digitally in this cable                                    

The main disadvantage of fiber optic cable is that cable are expensive to install. In addition they are more fragile then wire and are difficult to splice.                                                                                  

                                                                                                                                            

COAXIAL CABLE

There are many cables used in any network for communication. First of all we will take a look at Coaxial cable.
Coaxial cable is a kind of copper cable used by the cable TV companies between the community antina and user's home. This cable was invented in 1880 and invented by Oliver Heaviside.

As you can see in the diagram the cable is protected by Plastic jacket. Also Dielectric insulator is used here for protecting the inner interference and the electric signals travel through the central core, means the data is exchanged by the central core.

Coaxial Cable is of Two Types
Thin Net Coaxial Cable & Thick Net Coaxial Cable 

Thin Net Coaxial Cable :- The copper wire is Thin as the name says and the wire has less diameter. The range of this wire is 185 Meter, 10 base 2 , means 200 meter long and have 10 Mbps speed.

Thick Net Coaxial Cable:- This wire is Thick and having more diameter then upper discussed cable. This cable is known as 10 base 5 cable ( 500 meter long and 10 Mbps speed) 

HYBRID TOPOLOGY

Hybrid Topology:- The Hybrid topology is nothing it is the combination of two or more topology.

This is the mixture of two topology.