1 00:00:00,060 --> 00:00:03,000 Is a full duplex, communication is established. 2 00:00:04,060 --> 00:00:11,350 UDP is another protocol of transport layer layer four, used primarily for establishing low latency 3 00:00:11,350 --> 00:00:17,590 and loss, tolerating connections between applications on the Internet, TCP has emerged as a dominant 4 00:00:17,590 --> 00:00:22,960 protocol used for the bulk of Internet connectivity owing to its services for breaking large data sets 5 00:00:22,960 --> 00:00:29,710 into individual packets, checking for and resending lost packets and reassembling packets into the 6 00:00:29,710 --> 00:00:30,840 correct sequence. 7 00:00:31,510 --> 00:00:38,260 But these additional services come at a cost in terms of additional data overhead and delays called 8 00:00:38,260 --> 00:00:38,920 latency. 9 00:00:40,080 --> 00:00:47,940 In contrast, UDP just sends the packets, which means that it has a much lower bandwidth overhead and 10 00:00:47,940 --> 00:00:54,120 latency, but packets can be lost or received out of order as a result owing to the different paths 11 00:00:54,120 --> 00:00:57,200 individual packets traverse between center and receiver. 12 00:00:57,600 --> 00:01:04,280 So UDP uses a simple connection, less communication model with a minimum of protocol mechanism. 13 00:01:05,290 --> 00:01:12,250 It has no handshaking dialogues and thus exposes the users program to any unreliability of the underlying 14 00:01:12,250 --> 00:01:12,820 network. 15 00:01:13,570 --> 00:01:17,770 There is no guarantee of delivery, ordering or duplicate protection. 16 00:01:18,160 --> 00:01:25,360 UDP is suitable for purposes where error, checking and correction are either not necessary or are performed 17 00:01:25,570 --> 00:01:26,860 in the application. 18 00:01:28,490 --> 00:01:35,480 UDP is an ideal protocol for network applications in which perceive latency is critical, such as gaming 19 00:01:35,630 --> 00:01:41,780 voice and video communications, which can sever some data loss without adversely affecting perceived 20 00:01:41,780 --> 00:01:42,380 quality. 21 00:01:43,130 --> 00:01:49,910 In addition, since it's transaction oriented suitable for simple query response protocols such as the 22 00:01:50,150 --> 00:01:55,880 domain name system or the network time protocol, the UDP header is pretty simple. 23 00:01:56,540 --> 00:01:59,690 It consists of four fields, each of which is two bytes. 24 00:02:00,230 --> 00:02:01,130 Sixteen bits. 25 00:02:02,290 --> 00:02:08,140 The use of the fields checksum and Searsport is optional and IPV for. 26 00:02:09,310 --> 00:02:12,220 Are you surprised to hear that the Searsport is optional? 27 00:02:13,270 --> 00:02:18,250 But don't be because as you know, UDP packet does not expect to get a reply in general. 28 00:02:18,790 --> 00:02:25,240 And again, since UDP doesn't care about the errors, the checksum field is again optional. 29 00:02:26,410 --> 00:02:34,000 Searsport identifies as Henders Port and the destination port identifies the receiver's port as well. 30 00:02:35,130 --> 00:02:42,000 And the Langfield specifies the length of the UDP header and data in bytes, so now's a good time to 31 00:02:42,000 --> 00:02:46,130 compare the two protocols, UDP and TCP as a brief summary. 32 00:02:46,980 --> 00:02:54,870 Most services on the Internet use either TCP or UDP, which are carried end to end across the network 33 00:02:54,870 --> 00:02:59,370 using IP, either IP four or IPV six. 34 00:03:00,290 --> 00:03:07,340 The Transmission Control Protocol TCP and User Data Graham Protocol UDP are very different. 35 00:03:08,500 --> 00:03:15,930 TCP is a connection oriented protocol which tries to ensure reliable in order delivery of packets. 36 00:03:16,830 --> 00:03:25,380 If packets are lost, TCP automatically retransmit them, if they arrive out of order, TCP will resequence 37 00:03:25,380 --> 00:03:28,110 them before handing them up to an application. 38 00:03:29,750 --> 00:03:38,420 UDP is Connexions, the UDP software makes no attempt to associate streams of packets together, so 39 00:03:38,420 --> 00:03:43,580 as far as UDP is concerned, each packet is completely independent, unrelated to other packet. 40 00:03:44,240 --> 00:03:48,290 No attempt is made by UDP for retransmission or resequencing. 41 00:03:48,920 --> 00:03:54,860 If a packet is lost via UDP, it's up to the higher layer application to resend it.