In this blog I have tried to explain how a student can access google service from IT lab and try to understand how the communication takes place.
Let us assume Onkar is in IT lab and wants to access the google service: google classroom.
As per the layered networking system, when onkar tries to open the website, application layer creates the data i. e. a request to access the google server. After the completion of transport layer, network link layer and data link layer, Packet contains 4 adresses:
Onkar’s IP address
Onkar’s MAC address
Destination IP
Service point address: 443
Now that the data packet is created let us look at the diagram for a better understanding.
The data packet gets assigned a public/ gateway IP which is provided by the Internet service provider. This IP address is accessed by the switch 1 i.e. google server. The switch then sends a “hello” message to all its services. Google classroom recognises the IP and thus sends back a “hello” to confirm that its the right server. Google classroom will now send back a data packet granting access to access the server. Addresses in the reply packet are :
IP, MAC address
Destination IP
Service point address
This will grant access to Onkar for using the service of google classroom. He can now browse classroom from IT lab successfully.
Clicking on the link below, similar steps will occur before classroom is opened:
Classroom link: https://classroom.google.com/u/0/h
Comments