WEBVTT 00:00.620 --> 00:02.510 The Internet Protocol suite. 00:02.700 --> 00:07.400 TCP IP is a de facto protocol that modern networks use. 00:07.430 --> 00:12.650 Although you can think of the TCP IP as a single protocol, it's actually a combination of two protocols 00:12.680 --> 00:19.730 the transmission control protocol, TCP and the Internet protocol IP. 00:19.940 --> 00:24.860 And these two protocols form part of the Internet protocol suite. 00:24.890 --> 00:25.760 IP. 00:26.030 --> 00:27.590 So this is the Internet protocol suite. 00:27.590 --> 00:31.720 And these diagrams and I will explain all of these diagrams right now here. 00:31.730 --> 00:32.510 So. 00:33.760 --> 00:36.240 Um, and this Internet protocol suite. 00:36.250 --> 00:44.620 This is the conceptual model of how network protocols send network traffic over the Internet that breaks 00:44.620 --> 00:51.580 down network communication into four layer as shown in here. 00:51.580 --> 00:59.200 So application layer, transport layer, internet layer link layer and Ethernet IP is link layer IPv4. 00:59.200 --> 01:04.120 IPv6 is Internet layer, TCP and UDP is transport layer. 01:04.120 --> 01:06.610 Actually let me add comma here. 01:07.090 --> 01:15.820 TCP and UDP is transport layer HTTP SMTP, DNS is and etcetera is application layer and is actually 01:15.820 --> 01:24.790 these protocols are more but just this is just most used protocols in internet protocol suite and these 01:24.790 --> 01:26.680 are the external connections here. 01:26.680 --> 01:34.550 So the link layer directly connects to a physical network and also physical network connects directly 01:34.550 --> 01:36.740 to link layer here. 01:36.740 --> 01:39.800 So actually, let me get this here. 01:40.340 --> 01:45.320 Here and here I will apply the same for user application. 01:45.320 --> 01:45.980 Right? 01:47.130 --> 01:54.780 Here, whether it is a browser or just an online game, this is what works like that. 01:54.780 --> 01:57.840 So now I will explain Internet protocol suite. 01:57.870 --> 02:02.640 So let's get started with the link layer, the this link layer here. 02:02.640 --> 02:11.520 So this layer is the lowest level and describes the physical mechanisms used to transfer information 02:11.520 --> 02:20.070 between nodes on a local network and the well known examples include the Ethernet, both wired and wireless 02:20.070 --> 02:23.760 and the point to point protocol p, p. 02:23.770 --> 02:24.330 P. 02:24.510 --> 02:28.680 We also have the internet layer here. 02:29.040 --> 02:34.860 So this layer provides the mechanisms for addressing network nodes. 02:34.860 --> 02:42.090 And unlike in the in layer one, this the nodes doesn't have to be located on the local network. 02:42.120 --> 02:45.810 This level contains the IP on modern networks. 02:45.810 --> 02:50.230 The actual protocol used could be either IP version four or IP version six. 02:50.830 --> 02:54.400 And here we also have the transport layer. 02:54.430 --> 03:00.460 So this layer is responsible for connections between clients and servers and sometimes ensuring the 03:00.460 --> 03:03.220 correct order of packets and providing service. 03:03.220 --> 03:09.280 Multiplexing and service multiplexing allows a single node to support multiple different services by 03:09.280 --> 03:11.980 assigning a different number for each service. 03:11.980 --> 03:14.680 And this number is called the port. 03:14.710 --> 03:25.190 So the TCP and user datagram protocol operate on this layer and we also have the application layer. 03:25.210 --> 03:34.090 So this layer contains network protocols such as the hypertext transfer protocol HTTP, which transfers 03:34.210 --> 03:43.630 web page contents and the simple mail transport protocol SMTP, which transfers the email and the domain 03:43.630 --> 03:51.340 name system protocol DNS here, which converts a name to a node on the network. 03:51.350 --> 03:56.780 Throughout this course, we will focus primarily on this layer. 03:56.780 --> 04:04.780 Actually, in this section we will focus primarily on this layer, but in our all of our course you 04:04.790 --> 04:07.250 will learn all of these layers and protocols. 04:07.250 --> 04:09.200 So see you in next lecture.