1 00:00:01,630 --> 00:00:08,180 What come to the module focusing on wireless network standards and security solutions let's start by 2 00:00:08,180 --> 00:00:16,760 going back in time wireless LANs were first introduced in 1991 in the Netherlands over a short period 3 00:00:16,760 --> 00:00:23,140 of time they became globally sought after the working principle behind wireless networks is identical 4 00:00:23,140 --> 00:00:28,660 to the principle of wired networks that we talked about earlier or that of networks transferring data 5 00:00:28,660 --> 00:00:32,020 via optical signals. 6 00:00:32,030 --> 00:00:40,710 They also use the TCAP IP protocol stack fundamental differences in the medium vehicle for transmitting 7 00:00:40,710 --> 00:00:45,560 signal also the signal is no longer electrical or optical. 8 00:00:45,660 --> 00:00:47,500 It uses radio waves instead. 9 00:00:50,230 --> 00:00:55,780 A repercussion of this difference is that unlike wired networks wireless networks share the same carrier 10 00:00:55,780 --> 00:01:02,570 for all computers all hosts that are within the reception range of the transmitter and access point 11 00:01:07,560 --> 00:01:12,850 unlike in wired networks a potential attacker doesn't have to run a man in the middle attack whereas 12 00:01:12,880 --> 00:01:18,990 in the AARP cache or masquerade under a different IP address to eavesdrop on and control transferred 13 00:01:18,990 --> 00:01:26,050 communications establishing an unauthorized connection with a wireless network will remain unnoticed 14 00:01:26,050 --> 00:01:27,460 in most cases. 15 00:01:28,450 --> 00:01:32,910 It's possible to connect to a plane without the need for tampering with the network infrastructure. 16 00:01:34,030 --> 00:01:38,950 It doesn't require a physical presence in the office of a company whose network an intruder tries to 17 00:01:38,950 --> 00:01:46,030 break into any computer connected to an access point shares the medium with the other machines. 18 00:01:47,820 --> 00:01:55,220 This means that the data transferred over the same network including confidential data is in fact public. 19 00:01:55,260 --> 00:01:59,070 This is the key difference that separates wireless and wired networks. 20 00:01:59,970 --> 00:02:05,670 Whenever you connect to a Wi-Fi network can check your mailbox or log into an important system service 21 00:02:05,850 --> 00:02:08,570 or a social media Web site. 22 00:02:08,640 --> 00:02:12,420 You have to be aware that all interconnected users can access your information 23 00:02:16,620 --> 00:02:17,830 security wise. 24 00:02:17,850 --> 00:02:23,650 The worst scenario involves attackers taking control over the access point that can then force you to 25 00:02:23,650 --> 00:02:25,590 connect to the rogue access point. 26 00:02:26,770 --> 00:02:30,770 This situation will be examined more closely in this and the next part of this course 27 00:02:35,000 --> 00:02:38,140 Mel introduced you to wireless communications standards. 28 00:02:39,980 --> 00:02:44,810 Standard two point eleven The Wi-Fi standard is in fact a set of standards 29 00:02:50,150 --> 00:02:57,480 the first eight or two point eleven standard head of maximum data rate of two megabytes per second is 30 00:02:57,480 --> 00:03:00,240 one thing you need to know as far as standards are concerned. 31 00:03:01,380 --> 00:03:06,380 Since Wi-Fi networks are standardized they use the same frequency bands everywhere in the world. 32 00:03:08,790 --> 00:03:14,790 In contrast to CB radio or amateur radio users we don't have to file for a permit to use a particular 33 00:03:14,790 --> 00:03:17,900 frequency spectrum. 34 00:03:18,120 --> 00:03:24,130 The same wireless card used in Europe will also work in the US Asia or Africa. 35 00:03:24,140 --> 00:03:29,720 This is made possible through the implementation of wireless standards. 36 00:03:29,820 --> 00:03:35,010 Your original Ayro two point eleven standard was quite soon replaced with its B version. 37 00:03:35,140 --> 00:03:37,720 This version is fully retroactively compatible 38 00:03:41,060 --> 00:03:45,020 Amendment increases wireless network throughput to 11 megabytes per second 39 00:03:47,770 --> 00:03:53,950 version was released simultaneously with a two point eleven B. 40 00:03:54,010 --> 00:03:59,480 It's quite less popular as it is not compatible with Version B or with the original standard. 41 00:03:59,680 --> 00:04:02,770 Its strength lies in employing a different signalling method. 42 00:04:04,890 --> 00:04:11,080 It also uses a higher frequency the frequencies that can be seen in the chart in the picture or approximates 43 00:04:11,080 --> 00:04:18,670 only because each standard uses a specified number of channels depending on the country. 44 00:04:18,680 --> 00:04:26,080 There can be 11 or 13 channels adjacent channels can overlap. 45 00:04:26,140 --> 00:04:33,840 Neither realize that for example for the B version the frequency is never exactly 2.4 gigahertz successor 46 00:04:33,890 --> 00:04:38,550 B is the standard EDOT two point eleven G. 47 00:04:38,780 --> 00:04:41,270 It's used in business and homeland's even today. 48 00:04:41,750 --> 00:04:50,100 It's retroactively compatible with the B version and the original standard two point eleven g can transmit 49 00:04:50,100 --> 00:04:54,850 data over a relatively long distance with a speed of up to 54 megabytes per second. 50 00:04:56,950 --> 00:05:04,740 Between 2004 and 2005 the end version of the standard was introduced and gained popularity were given 51 00:05:04,740 --> 00:05:10,020 an advantage over the previous versions was the improved reliability and extended range of the wireless 52 00:05:10,020 --> 00:05:17,030 transmission in radio two point eleven n. the same signal can be transmitted and received by multiple 53 00:05:17,030 --> 00:05:19,040 antennas where access points 54 00:05:25,390 --> 00:05:30,210 originally the radio two point eleven standard used not only radio waves to transport data. 55 00:05:30,730 --> 00:05:34,710 It also defined infrared transmission. 56 00:05:34,710 --> 00:05:39,530 The standard however failed to achieve popularity and was supplanted with other technologies.