1
00:00:00,060 --> 00:00:04,670
Hello, everyone, welcome to our new series of Wi-Fi testing with Python.

2
00:00:06,000 --> 00:00:09,450
In this lesson, we will discuss free wireless terminologies.

3
00:00:14,280 --> 00:00:20,790
Let's start with the AP or access point, the access point is basically a wireless router you have at

4
00:00:20,790 --> 00:00:27,600
home where at work it doesn't have to be also a router because router does routing decisions based on

5
00:00:27,600 --> 00:00:29,390
the best the best part.

6
00:00:30,660 --> 00:00:38,130
But you can have any access point like TCP link or D link, but only works as access points, which

7
00:00:38,130 --> 00:00:41,880
allows users to connect to it and become in the same network.

8
00:00:43,470 --> 00:00:50,640
The service set identifier or as a side is basically the network name you connect to using your phone

9
00:00:50,640 --> 00:00:51,530
or your laptop.

10
00:00:53,130 --> 00:01:00,120
The basic service set identifier or BSA side is the Mac address or the layer to address of your access

11
00:01:00,120 --> 00:01:00,510
point.

12
00:01:02,010 --> 00:01:02,950
The channel number.

13
00:01:02,970 --> 00:01:07,730
This is the frequency which your access point is using for receiving and transmitting data.

14
00:01:08,550 --> 00:01:14,490
Like, for instance, if you have an access point using two point four gigahertz, this frequency is

15
00:01:14,490 --> 00:01:19,260
uses, but also the channels themselves have all different frequencies.

16
00:01:19,830 --> 00:01:21,010
We will get to this later.

17
00:01:22,890 --> 00:01:27,060
Now we will dive deeper into the 2.0 frame types.

18
00:01:31,060 --> 00:01:36,850
The most important frames we want to talk about are the data frame, the control frame and the management

19
00:01:36,850 --> 00:01:44,320
frame that one we will focus on more in this wi fi protesting series is the management frames.

20
00:01:48,640 --> 00:01:56,080
Now, as you see, the Mac header has nine fields in it, but we will focus now on ADRIS one, two and

21
00:01:56,080 --> 00:02:03,580
three, which, as you can see, Adris one holds the Mac address of the destination address to is the

22
00:02:03,580 --> 00:02:07,310
Mac address of the Access Point or the BSA side.

23
00:02:07,420 --> 00:02:08,410
We talked about before.

24
00:02:08,410 --> 00:02:08,700
Right.

25
00:02:09,550 --> 00:02:12,070
And that history is the address of the source.

26
00:02:14,020 --> 00:02:20,320
So if we are sending frame from our laptop to to the access point, then the source Mac address will

27
00:02:20,350 --> 00:02:28,480
be our laptop and address one and address to will be the same, which is the Access Point Mac address,

28
00:02:28,480 --> 00:02:34,200
because we are sending from our laptop, which is a source to the access point, which is the destination.

29
00:02:34,360 --> 00:02:34,780
Right.

30
00:02:36,250 --> 00:02:37,240
So far, so good.

31
00:02:37,690 --> 00:02:40,270
Now let's take a look at the management frame types.

32
00:02:45,420 --> 00:02:53,400
We have here the authentication from Death Education Free Association request from this association

33
00:02:53,400 --> 00:02:56,680
for probe request and probe response.

34
00:02:57,990 --> 00:02:59,730
Let's see how it works, Insteps.

35
00:03:03,130 --> 00:03:08,920
First, your laptop will scan for any access points and range by checking the beacon frames coming from

36
00:03:08,920 --> 00:03:15,680
those access points the beacon frames have as A side and B as a side of the access point.

37
00:03:16,300 --> 00:03:18,780
It's like advertising itself to the world.

38
00:03:19,900 --> 00:03:25,300
Once your laptop sees the beacon signal, you can have the choice to connect to it or not.

39
00:03:26,890 --> 00:03:33,040
If you chose to connect, then your laptop will start a sequence of frames exchange like in the picture.

40
00:03:34,570 --> 00:03:36,460
It starts with a probe request.

41
00:03:36,580 --> 00:03:40,270
Then the access point replies back with a probe, a probe response.

42
00:03:41,050 --> 00:03:44,290
This probe request is to check if the access point is there or not.

43
00:03:44,710 --> 00:03:51,910
So even if after you successfully connect to to your access point, your laptop will keep doing this

44
00:03:51,910 --> 00:04:00,070
from time to time, even if the access point is out of range next to authentication frames, followed

45
00:04:00,070 --> 00:04:02,590
by two association frames.

46
00:04:04,750 --> 00:04:06,100
There are other frames as well.

47
00:04:06,130 --> 00:04:13,750
We will discuss later like that disassociation frame or the documentation frame in the next video.

48
00:04:13,750 --> 00:04:16,480
We will look at some of those frames using Wireshark.

49
00:04:17,860 --> 00:04:18,550
Thank you.

50
00:04:18,550 --> 00:04:19,870
And see you in the next video.