Video transcripts

Transcript

1. 0:00Let's start with a simple idea.
2. 0:02At its core,
3. 0:03the purpose of all communications is to exchange information and ideas
4. 0:07between people and organizations so that work can get done.
5. 0:11In the digital world,
6. 0:13this means building secure,
7. 0:14reliable,
8. 0:15and effective networks that make this exchange possible.
9. 0:19Any communication system should be able to answer 6 basic
10. 0:19questions
11. 0:23who
12. 0:23is sending the message and who is receiving it?
13. 0:26What is being sent?
14. 0:28Where are the sender and recipient located?
15. 0:31Why do they need to communicate?
16. 0:33When must the message be sent and received?
17. 0:36And how should it be sent?
18. 0:38Each of these must align with the organization's security policies
19. 0:42to design secure and effective network systems,
20. 0:45two architectural models dominate the landscape.
21. 0:48First,
22. 0:49the TCP
23. 0:50IP model developed by the Internet Engineering Task Force.
24. 0:55Second,
25. 0:56the OSI 7 layer model published
26. 0:58by the International Organization for Standardization.
27. 1:02While they differ in some structure,
28. 1:04these models share key concepts and help guide secure network design.
29. 1:08These models share common goals,
30. 1:11provide reliable and manageable communication between systems,
31. 1:15organize networking functions in layers.
32. 1:18Use packets to transmit information.
33. 1:21Standardize addressing,
34. 1:22routing and control processes.
35. 1:25Allow flexibility and innovation at the application layers.
36. 1:29Remain scalable,
37. 1:30vendor agnostic,
38. 1:31and resilient.
39. 1:33The communication process begins with a user at an endpoint,
40. 1:37perhaps using a browser or an email client.
41. 1:40That application uses the protocol stack to format the message for delivery.
42. 1:45Each layer in the stack adds its own instructions and data,
43. 1:48creating an encapsulated packet ready to travel across the network.
44. 1:53The lower layers of the stack handle encapsulation.
45. 1:56Each layer wraps the message with additional information like destination,
46. 2:00routing,
47. 2:01and error checking details before passing it to the next layer down.
48. 2:05As the packet travels to its destination,
49. 2:08the process is reversed.
50. 2:09Each layer unwraps its part of the data until
51. 2:12the message reaches its intended recipient in usable form.
52. 2:16Internet networking refers to how two systems with different
53. 2:19underlying architectures and protocols can
54. 2:22still exchange information successfully.
55. 2:24It's what allows global communication between millions
56. 2:27of devices regardless of who made them,
57. 2:29what software they run,
58. 2:31or where they are located.