OSI Model

OSI- Open System Interconnection Model.

OSI model is a conceptual and logical layout that defines network communication or we can say that  for defining standards for connecting computers.

It was developed by ISO( International Organization for Standardization).

So there are seven layers in OSI model and these are...

      7. Application layer

        6. Presentation layer

5. Session layer

   4. Transport layer

  3. Network layer

   2. Data link layer

  1. physical layer

Layer 7: Application Layer

   It is the top most layer in which the users interaction with the computer.

examples are: firefox, Internet explorer, operamini etc.

Layer 6: Presentation Layer

   It is the layer in which the Operating System comes in work. Actually it works as a translator between the application and the network.

Layer 5: Session Layer

   This layer estabilish, manage and terminate the session between communicating devices.

Layer 4: Transport Layer

   This layer has the responsibility to transfer the data completely and ensure that there should not be any duplication of the data packet.

Layer 3: Network Layer

   It determines the best path to move data from source to the destination based on the network conditions, the priority of service, and other factors.

This layer checks the IP address and works on the behalf of the IP address.

This layer contains the functionality of routers.

Layer 2: Data link Layer

   This layer is responsible for the error-free transfer of data frames.

This layer contains the operation of Switches.

Layer 1: Physical Layer

   This is the physical media and main functionality of the physical layer is to transmit the individual bits from one node to another node.

This layer contains the Patch pannel, Cabling etc.

NETWORK CABLING

In Networking, It is essential to need cables for transmission of data. If there is no transmission of data then there is no need of netwoking.

So, we need cables for data transmission.

TYPES OF CABLES

 

  1. Category-3 Cable: These types of cables generally gives speed of 10 Mb/sec.

   

  2. Category-5 Cables: These types of cables generally gives speed of  1Gb/sec.

  3. Category-6 Cables: These types of cables generally gives speed of 10Gb/sec.

 When we talk about networking cables there is a term comes forward that is Jacks...

    A jack is simply the cable end which helps to connect with the devices.

There' a lot of connectors(or jacks) which are:

  1. USB (Universal Serial Bus): It is generally used to connect the peripherals to the PC such as keyboard, mouse, modem, etc.

• USB 1.1 - It supports data transfer rates of 12 Mbps.
• USB 2.0 - (also known as Hi-Speed USB) It supports data transfer rates of 480 Mbps.  

The USB 2.0 is fully compatible with USB 1.1,  and also there is no difference between there cables and connector

The USB connector comes in two types: Type-A and Type-B.

first one is Type-A and second one is Type-B

2. RJ-11 (Registered Jacks): RJ-11 connector is used in telephone equipments. It is a four or six wire connector.

 

  RJ-11 Pin          Signal Name

1.                     VCC (5V)
2.                      Power Ground
3.                      One Wire Data
4.                      One Wire Ground

RJ-11 connector

3. RJ-45( Registered Jacks): This connector is used in networking and it is an eight wire connector and commonly used to connect computer to the LANs.

RJ-45 connector

4. F-Type: These types of connectors are used to connect satellite television. You can see these connectors in your cable TV.

F-type connector