WEBVTT 00:00.560 --> 00:01.700 Data encapsulation. 00:03.100 --> 00:07.420 Each layer in the pipes is built on the one below. 00:08.950 --> 00:15.730 So and each player is able to encapsulate the data from the layer a bore so it can move between the 00:15.730 --> 00:16.710 layers of. 00:18.170 --> 00:20.180 So, um. 00:21.370 --> 00:29.560 Data transmitted by each layer is called protocol data unit, as you can see here in this here, bidirectional 00:29.770 --> 00:32.310 directional direction and not data show. 00:33.130 --> 00:36.730 So we have heaters, futures and addresses. 00:37.030 --> 00:44.200 So TPD or protocol data unit in each layer contains the payload data that is being transmitted. 00:45.190 --> 00:49.210 So it's common prefix heder, which contains. 00:50.420 --> 00:55.260 And as you can see here, eternity, the IP, that is he. 00:57.690 --> 00:58.950 DCP, they're here. 00:59.580 --> 01:07.740 And for the pain, this heder contains information required for the payload data to be transmitted, 01:08.130 --> 01:14.010 such as the addresses of the source and this nation nodes on the network, your source address, destination 01:14.010 --> 01:18.060 address or so there's this notion that there's source this destination port. 01:23.530 --> 01:24.550 So actually. 01:26.630 --> 01:34.910 Sometimes a Purdue also has a future, and that is just like a sister to the payload data and contents 01:34.910 --> 01:39.890 values needed to ensure correct transmission, such as error checking information. 01:41.150 --> 01:41.660 So. 01:43.020 --> 01:47.400 And this figure here, as you can see here, shows the UM. 01:49.600 --> 01:54.210 PED use are laid out in the pipes. 01:55.460 --> 01:56.900 So as you can see here. 01:58.270 --> 02:06.120 Now, the TCP, he contains a source and this nation port number here, source port destination port, 02:06.130 --> 02:08.530 as you can see here, source port in this nation port. 02:08.890 --> 02:17.050 So these ports are a single lot that have multiple unique network connections, so a port numbers intercept 02:17.140 --> 02:17.440 here. 02:17.680 --> 02:19.480 Let's let me mention here. 02:20.080 --> 02:20.570 Um? 02:23.070 --> 02:24.470 So this means deep here. 02:24.670 --> 02:33.180 Uh, port numbers, um, near the port numbers in TCP. 02:34.690 --> 02:37.870 These port numbers, actually. 02:41.790 --> 02:51.900 Port numbers, numbers in TCP or UDP starts star. 02:52.590 --> 02:55.100 It's, uh, star. 02:55.950 --> 03:04.410 It's from zero, uh, two six six two five thousand five hundred thirty five. 03:07.610 --> 03:07.910 Yes. 03:09.490 --> 03:18.010 So most port numbers are assigned up to as needed into a new connections, but some numbers have been 03:18.010 --> 03:21.160 given special assignments. 03:21.170 --> 03:24.610 So for example, um, port. 03:27.330 --> 03:28.970 Port, No. 03:29.710 --> 03:30.370 No. 03:30.900 --> 03:35.640 80 is for A.P. Protocol. 03:37.410 --> 03:43.890 And 2021 for FTP protocol and and of. 03:47.070 --> 03:47.940 And more. 03:51.320 --> 03:59.060 So you can find the currently is a sign for numbers in the ATC services file on the most unique slice 03:59.060 --> 03:59.870 operating system. 04:00.170 --> 04:03.760 So a TCP payload A. There are UM. 04:06.070 --> 04:13.780 Commonly called a segment which when I was a UDP pilot and Hayder are commonly called data around, 04:14.410 --> 04:23.050 so the IP protocol uses a source and this nation address here, as you can see here, IP port source 04:23.050 --> 04:25.390 address and destination address. 04:26.200 --> 04:33.340 So this nation address allows the data to be sent to a specific note on the network at the source address 04:33.340 --> 04:39.160 along the receiver of the data to know which not since the data and the laws. 04:39.160 --> 04:42.670 The receiver to Ripley that they reply to the sender. 04:43.030 --> 04:46.600 So IPv4 uses 32 bit addresses here. 04:46.900 --> 04:49.150 Let's mention this also here. 04:50.020 --> 04:50.500 Uh. 04:52.600 --> 04:55.030 Actually, yes, IPV. 04:56.390 --> 04:58.140 IP version four, Oops. 05:04.440 --> 05:05.130 IP. 05:06.390 --> 05:12.900 IP version four uses 64 actually not six words, 32 bit. 05:14.550 --> 05:16.560 32Bit addresses. 05:19.200 --> 05:19.800 So. 05:22.400 --> 05:25.490 Which you will typically see it and the number separated by dust. 05:25.940 --> 05:33.230 For example, here one thousand one hundred thirty two, one hundred sixty eight with zero point one. 05:33.710 --> 05:43.880 So these are the 32 bit addresses so um and separated by dots, as you can see here, but IP, for example. 05:44.270 --> 05:45.980 But IPv4 here. 05:47.070 --> 05:48.960 It's good to mention the troops here. 05:49.170 --> 05:54.030 It's useful IPV I've seen excellent Typekit for IP. 05:54.060 --> 06:03.030 IP version six IP 06 users actually want one hundred, uh, twenty eight bit addresses. 06:03.540 --> 06:04.320 One hundred. 06:11.000 --> 06:16.670 128 of 128 bit at recess. 06:18.720 --> 06:27.030 So because 32 bit other sins are insufficient for the number of nodes on a modern network. 06:28.100 --> 06:39.230 So, for example, for example, here, for example, if you're 80, zero zero zero zero zero zero, 06:39.680 --> 06:48.470 for example, and like that, so IPV six addresses are usually written as hexadecimal numbers separated 06:48.470 --> 06:54.900 by dots such as this by common sexual thoughts. 06:54.950 --> 07:00.260 As you can see here, IPV six is separated by colors, but IPv4 is separated by dots. 07:01.220 --> 07:07.640 So that is here of what data rights with hexadecimal numbers. 07:07.640 --> 07:14.130 For example, in a b, it might, uh, ninety and one two. 07:14.540 --> 07:15.380 He had elected. 07:16.570 --> 07:17.530 Uh, so. 07:22.020 --> 07:28.260 Long stints of two zero, four times zero numbers are collapsed into two columns. 07:28.650 --> 07:36.090 For example, these uh, here these four four zero can be written like just stats. 07:36.090 --> 07:46.110 So this is the same as previously, so they tended also contains a source and the destination addresses, 07:46.860 --> 07:48.450 for example, here. 07:49.610 --> 07:54.740 Source and destination addresses in eternity, air source and destination analysis. 07:56.140 --> 08:03.550 So, uh, so this eternity uses 64 bit value called media access control here. 08:04.760 --> 08:06.110 A term that uses. 08:07.840 --> 08:13.540 Internet users, 64 bit, actually, it's 64 bit, right, yes. 08:13.870 --> 08:16.000 64 bit Mac. 08:17.060 --> 08:20.930 Addresses addresses which called. 08:23.410 --> 08:29.380 And we, um, other sis called Mac, what is Mac mean? 08:29.960 --> 08:34.720 Uh, this Mac man is media access control, media access. 08:36.440 --> 08:36.980 Control. 08:38.630 --> 08:44.150 So, which is typically set during manufacture of the Ethernet adapter, you will usually see Mac addresses 08:44.150 --> 08:49.280 for it in a serious, serious of hexadecimal numbers, for example. 08:49.760 --> 08:52.830 Um, actually like that here. 08:54.360 --> 09:06.800 Zero a uh, for example, the zero zero, 27, uh, 90 90, uh, a b or f zero like that. 09:07.610 --> 09:13.940 So the Ethernet payload, a payload, including the heater and footer, is commonly referred to as frame 09:15.350 --> 09:16.640 here, as you can see here. 09:20.680 --> 09:21.010 Yes. 09:22.030 --> 09:27.010 And you can see here we what did, and I created an illustration here.