0:02 hello everyone welcome back to the
0:04 computer networks course today we will
0:06 see the classification of computer
0:08 networks after completing this session
0:10 we will understand what are LAN
0:13 man and when and after understanding Lam
0:14 van and man
0:15 we will also understand what are the
0:18 devices that are involved in land man
0:20 and man and we will also understand what
0:22 are the new trends in computer network
0:24 we will see the classification of
0:26 computer networks computer networks are
0:29 classified into local area network or
0:31 simply land metropolitan area network or
0:34 simply man wide area network or simply
0:37 van we will see local area networks
0:40 first as the name implies local means it
0:43 is restricted to one limited area that
0:45 is a small network is said to be a local
0:48 area network a local area network is a
0:50 computer network that interconnects
0:52 computers within a limited area say a
0:54 small network that is there in our
0:57 residence or a school lab University
1:00 campus or office is said to be a local
1:03 area network let's take an example let
1:05 there are hundred computers in a network
1:08 and this is a school network each of
1:09 these computers are connected to each
1:12 other with the help of a switch and we
1:14 can call this computer network as a
1:17 local area network why because all these
1:19 computers can communicate with each
1:21 other internally we can set a plan in
1:24 two ways one is a wired LAN another on a
1:26 servile aslam in Wired LAN we have
1:29 cables so the example technology for a
1:31 wired LAN is Ethernet we have already
1:33 seen in the previous lecture that
1:35 Ethernet is used to connect two or more
1:37 nodes in this case this node is
1:40 connected to the switch this computer is
1:41 connected to the switch with the help of
1:44 an Ethernet cable to be precise this is
1:46 an Ethernet straight through cable
1:48 because Ethernet straight through cable
1:50 connects devices of different kinds
1:52 switch and computers are different kinds
1:54 of devices so we need to use Ethernet
1:56 straight through cable in case if we
1:57 want to connect this computer with E
2:00 this computer directly then we have to
2:02 go for Ethernet crossover cable whatever
2:05 it is Ethernet is the well known and the
2:07 most popular technology in wired LAN and
2:09 the devices that are used in the wired
2:12 LAN are hub and switched I will talk
2:13 about this happen switch in the
2:16 next lecture elaborately now you just
2:18 understand hub or switch can be an
2:19 intermediary device in a local area
2:22 network and that do in a wired local
2:24 area network we can also have a local
2:28 area network Wireless example Wi-Fi now
2:30 we will see metropolitan area network or
2:32 simply man a metropolitan area network
2:35 is a computer network that interconnects
2:38 uses or computers in a geographic region
2:42 see there are two branches in a CTE and
2:44 these two branches are somehow connected
2:46 with each other so this kind of network
2:48 is called as a metropolitan area network
2:51 in other words there are two local area
2:53 networks these two local area networks
2:56 are connected to each other in a city
2:58 the device is involved in this
3:00 metropolitan area network are switches
3:02 hubs for establishing a local area
3:04 network and to connect to local area
3:07 networks we need routers or bridges as I
3:09 already mentioned there are minimum two
3:11 local area network and these two local
3:13 area networks are to be connected with
3:15 each other with the help of a router or
3:17 a bridge we will see an example now
3:20 there are four local area networks
3:22 connected to each other let's say this
3:24 is a supermarket and this supermarket
3:26 has four branches computers in one
3:29 supermarket will be in one local area
3:31 network similarly other branches also
3:33 have separate local area network and
3:36 these supermarket branches must somehow
3:38 communicate with each other for example
3:40 if someone is asking for a product which
3:42 is not there in this branch the employ
3:44 of this branch wants to search whether
3:46 the product is available in other
3:48 branches this is possible only if all
3:51 local area networks of the supermarket
3:53 are connected and this is what exactly a
3:55 metropolitan area network please
3:58 remember this is restricted to only a
4:00 small geographic region like a city
4:02 please note in every length there are
4:04 some computers and these computers can
4:06 communicate with other computers in
4:08 other local area network and this is
4:11 possible only if these computers are
4:13 somehow connected with each other
4:16 time to see wild area network that is
4:19 the van a voluntary Anette work is a
4:21 telecommunications network that extends
4:24 over a large geographical area it means
4:27 it is a telecommunications network but
4:30 it deals with a larger geographical area
4:31 first we will see what is a
4:33 telecommunications network any
4:36 communications at a distance we call it
4:39 as a telecommunication network so here
4:41 the communication is going to be within
4:45 a large geographical area in Man two or
4:47 more lands within a city can communicate
4:50 with each other in van two or more lands
4:52 within a country can communicate with
4:55 each other and the devices in van are or
4:57 in devices and intermediary devices
5:00 because an ending
5:02 may want to communicate with an end
5:03 device which is in the other part of the
5:05 country and some authors will refer this
5:08 wide area network to be the Internet we
5:10 will see an example now and there are
5:13 two local area networks one local area
5:16 network is in New Delhi and other local
5:18 area network is in Chennai and these two
5:20 local area network are in two different
5:22 places in the country and they are
5:24 separated by a very large geographical
5:27 area but still this computer can
5:29 communicate with this computer and this
5:31 is possible only with the help of a wide
5:34 area network wide area network means
5:37 communication at a large distance if it
5:39 is a man this is possible only within a
5:42 city but this is wide area network hence
5:44 the communication at the distance is
5:47 still possible so far we have seen local
5:49 area network metropolitan area network
5:52 and wide area network now we will see
5:55 the Internet I will say this is a wild
5:57 wide area network that is a wide van why
5:59 because there are so many local area
6:02 networks so many metropolitan area
6:04 networks and so many wide area networks
6:06 across the world are connected to each
6:08 other say for example there is a guy in
6:10 India who wants to send some data to a
6:12 guy who is in Australia between India
6:14 and Australia there are many routers
6:17 involved in taking the data from India
6:18 to Australia
6:20 similarly every country in the world is
6:22 somehow connected with other countries
6:23 through computer networks we don't know
6:25 whether two countries have a friendly
6:27 relationship or not but definitely they
6:28 will have a computer network
6:29 relationship and that's the power of
6:32 computer network guys before we conclude
6:34 we will see the new trends in computer
6:37 networks nowadays many employees are
6:39 encouraged by their employers to bring
6:40 their own device and
6:43 to the office Network and we shall call
6:44 such scenario as a bring-your-own-device
6:48 scenario it means employees can bring
6:49 their own device and connect it to their
6:51 office network and still work with
6:53 office network coming to the online collaboration
6:54 collaboration
6:56 once upon a time if a meeting is
6:59 scheduled everyone has to assemble in
7:01 the meeting spot now the trend has
7:03 completely been changed they can
7:05 participate from wherever they are and
7:07 they can still do online collaboration
7:09 with others with the help of computer network
7:09 network
7:12 say for example a meeting involves
7:14 participants in New Delhi Chennai
7:18 America Australia but still no one to be
7:19 there in a particular or a specific
7:22 location they can be wherever they are
7:23 but still they can do online
7:25 collaboration and cloud computing is the
7:27 new trend that we would like to address
7:30 cloud computing means it is the
7:32 on-demand availability of computer
7:34 resources first let's take an example
7:36 let's take Google Drive one can store
7:38 all files and folders in Google Drive
7:41 that gives a lot of flexibility if one
7:43 wants to accesses files from any part of
7:45 the world he can access by just giving a
7:46 request to Google Drive and download the
7:49 data what if he had stored the data in
7:51 his personal computer he needs to carry
7:53 the computer wherever he goes if he
7:55 wants the data with him but cloud
7:57 computing say this Google Drive offers
8:00 this on-demand availability cloud
8:02 computing is the on-demand availability
8:04 of computer resources especially data
8:06 storage and this computing we need not
8:08 directly involve in the management we
8:09 can just store the data somewhere in a
8:12 secure manner and get the data whenever
8:14 we wanted that's the power of cloud
8:17 computing that's it guys in the initial
8:19 part of the session we have listed that
8:21 we are going to learn certain things now
8:22 we will ensure whether we have learnt
8:25 all these things I hope now you have
8:26 learned what is local area network
8:28 metropolitan area network and wide area
8:31 network and we have also seen what are
8:33 the various devices involved in LAN
8:35 man and van and there are some new
8:36 trends that are there in the computer
8:38 networking field and we have also seen
8:41 those trends thank you for watching [Applause]
8:43 [Applause] [Music]
8:51 you [Music]
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