1 00:00:00,650 --> 00:00:08,540 So this is once again an example of an external CCU DSU connected using a v 35 cable to a router. 2 00:00:08,720 --> 00:00:13,910 Here's an example with the WHIC card having the CCU DSU built in. 3 00:00:14,420 --> 00:00:18,710 So what's the built in CCU dsu such as a wicker one? 4 00:00:18,710 --> 00:00:20,180 DSU DT one. 5 00:00:20,450 --> 00:00:26,300 The card would be used to connect to either PT one or fractional PT one connections. 6 00:00:26,720 --> 00:00:33,830 The advantage of using this card over an external CCU DSU is that you have fewer devices and cables 7 00:00:33,830 --> 00:00:35,150 to deploy and manage. 8 00:00:35,850 --> 00:00:43,140 It also allows you to remotely configure, monitor and troubleshoot using the well-known Cisco CLI. 9 00:00:43,380 --> 00:00:47,070 And it obviously saves some space because you have fewer devices. 10 00:00:47,250 --> 00:00:53,940 So in many cases in the United States, people would use the bolt in AC DC, but in other parts of the 11 00:00:53,940 --> 00:00:58,500 world you may still be required to use an external CCU DC. 12 00:00:58,740 --> 00:01:01,890 So what are some of the advantages of a leased line? 13 00:01:02,100 --> 00:01:04,530 Well, firstly, it's very simple to configure. 14 00:01:04,560 --> 00:01:09,060 You can get a lease line up and running with just a few commands. 15 00:01:09,210 --> 00:01:12,720 So it's very simple to install and maintain point to point. 16 00:01:12,750 --> 00:01:18,840 Lease lines also offer a high quality of service, provided that there's adequate bandwidth for the 17 00:01:18,840 --> 00:01:20,610 traffic traversing the link. 18 00:01:20,730 --> 00:01:26,370 In other words, the bandwidth of the connection is dedicated to you and you alone. 19 00:01:26,430 --> 00:01:30,240 No one else will be able to use the bandwidth on that circuit. 20 00:01:30,300 --> 00:01:36,990 You are typically paying a monthly charge for the leased line and the bandwidth on that leased line 21 00:01:36,990 --> 00:01:38,880 is dedicated to you alone. 22 00:01:39,240 --> 00:01:44,640 The connection is also permanent, so you don't have to try and set it up every time you send traffic. 23 00:01:44,970 --> 00:01:49,860 The bandwidth is there and they're always for you to use. 24 00:01:50,540 --> 00:01:56,930 The major disadvantage of the lease lines, however, is normally the cost of the leased line. 25 00:01:57,200 --> 00:02:01,640 Now, if you've only got two sites, the cost may not be that great. 26 00:02:01,670 --> 00:02:05,600 However, if you've got ten sites that you need to connect in a full mesh. 27 00:02:05,630 --> 00:02:09,350 In other words, every site needs to be connected to every other site. 28 00:02:09,500 --> 00:02:15,680 The cost can become very prohibitive as there's an exponential increase in the cost as you add more 29 00:02:15,680 --> 00:02:16,700 and more sites. 30 00:02:17,060 --> 00:02:23,870 That's one of the reasons that small, medium businesses today prefer to use DSL connections with VPNs 31 00:02:23,870 --> 00:02:31,580 rather than using leased lines and large businesses when making connections to remote branch offices 32 00:02:31,580 --> 00:02:36,750 may also prefer to use the Internet with DSL as the local connection type. 33 00:02:36,770 --> 00:02:43,070 With VPNs overlayed across the Internet, it's a lot, lot cheaper, especially when you have many, 34 00:02:43,070 --> 00:02:44,000 many sites. 35 00:02:44,390 --> 00:02:50,420 Another problem is you are charged for the bandwidth, whether you use it or not. 36 00:02:50,600 --> 00:02:56,300 So as an example, if you've got a two megabits per second circuit or two megabits per second, at least 37 00:02:56,300 --> 00:03:03,200 line, you are charged a monthly fee for that last line whether you use the bandwidth or not. 38 00:03:03,530 --> 00:03:09,680 If you only using some of the bandwidth, some of the time you are paying for bandwidth that you don't 39 00:03:09,680 --> 00:03:10,460 use. 40 00:03:10,460 --> 00:03:12,830 So that's another disadvantage of at least line. 41 00:03:12,950 --> 00:03:18,980 You also have no ability to burst or go above the fixed limit of two megabits per second. 42 00:03:19,160 --> 00:03:22,370 You are limited to the speed of the link. 43 00:03:22,580 --> 00:03:29,090 The bandwidth is yours to use all the time, but you can't go above the speed of the least line.