How the Internet Works

Question 1

1) UDP

Answer 1

Browser sends User Datagram Protocol (UDP) to DNS server (dns server typically belongs to the ISP)

Question 2

2) DNS action

Answer 2

DNS server either knows the domain name, in which case it gets an IP translation, the IP address of the ANS (authoritative name server) or a parent of it that knows how to reach the ANS

Question 3

3) After locating ANS

Answer 3

translated IP address is returned to the client and its browser. If ANS can’t be found, error is returned

Question 4

4) Browser action

Answer 4

Browser sends preferences for TCP communication (window size, etc)

Question 5

5) Browser request ->

Answer 5

Request is routed to “central” ISP server which forwards request to the CO of the destination and then to the server

Question 6

6) Server action

Answer 6

Server accepts or denies request. If accept, sends back its own preferences

Question 7

7) Browser action

Answer 7

If browser agrees to server requirements, connection is established

Question 8

8) Browser RESTful request

Answer 8

Browser sends HTTP GET request which may includes cached “cookies” from previous interactions

Question 9

9) Server receives request

Answer 9

Server receives request, agrees/disagrees, and returns an HTTP response (in the form of an HTML page display)

Question 10

10) HTML is rendered in the client’s browser

Answer 10

and other GET requests are sent by client and returned by the server

Question 11

AJAX

Answer 11

(async JavaScript and XML) can expedite JavaScript asynchronously making in-page requests to a server