computer networks prince dudhatra 9724949948
Post on 08-Apr-2018
225 Views
Preview:
TRANSCRIPT
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 1/68
Computer Networks
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 2/68
What do you mean by network ?
Network means interconnections of two or more systems. The minimum number of
system required to make a network is two.Computer systems connected in a networkcan exchange information betweenthemselves.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 3/68
Computer networks are of three types
Local Area Network ( LAN)
Metropolitan Area Network ( MAN)
Wide Area Network ( WAN)
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 4/68
Local Area Network ( LAN)
Networks that connect computers lying within asmall distance from each other such are calledLAN.
Local area networks normally use coaxial cablesto connect the computers together.LAN is used in building, rooms etc.Two or more computers connected to each other
can share data and their peripherals such asprinters, modems etc.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 5/68
Local Area Network (cont.)
Applications performed by a LAN are asfollows
1) File transfer and access2) Accessing the internet3) Providing Management Information Systems
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 6/68
M etropolitan Area Network ( M AN)
A metropolitan area network uses thedistributed queue dual bus. The MAN is largerthan a LAN.
Metropolitan Area Network is used betweencities
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 7/68
Wide Area Network (WAN)
A wide area network connects computerswhich are very remotely placed.
It may connect across the countries orcontinents or the entire globe.
Wide Area Networks are also referred to asLong Haul Networks (LHNs).
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 8/68
R outing
When data is to be transmitted between tworemote machines using intermediatemachines is called Routing.Intermediate machines are as follows :-
1) Gateways or routers
2) Repeaters3) Bridges
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 9/68
G ateways or R outers
Gateway is one of several types of communication servers. The function of agateway is to allow two or more dissimilarnetworks to communicate as a single logicalentity. The two machines that have to transferdata between themselves may have different
operating systems (OS) or their transportprotocols may be different. It is then the job of the gateway to connect such machines.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 10/68
R epeaters
A repeater receives the incoming signal,repeats it or amplifies it and retransmits thetransformed signal. After certain distances thesignal experiences a loss of power hence arepeater is required to boost the power of thesignal. By using repeaters the network can be
extended but on only finite extension ispossible due to physical constraints such asnoise.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 11/68
B ridges
A bridge is a device that is used to connect twonetworks so that they are able to perform as one.A bridge can also be used to connect two
networks that use the same technology, such asthe Ethernet network and then Token Ringnetwork.One of the main functions of the bridge is topartition one large network into two networkswhich subsequently increases the performance of the network.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 12/68
R outing Techniques
C omputer network may use following routingtechniques :-
1)C
ircuit Switching
2) Packet Switching
3) Message Switching
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 13/68
Cir cu it Sw itch ing
Circuit switching is defined as a mechanism applied intelecommunications whereby the user is allocated the fulluse of the communication channel for the duration of the call.That is if two parties wish to communicate, the calling party
has to first dial the numbers of the called party. Once thosenumbers are dialed, the originating exchange will find a pathto the terminating exchange, which will in turn find the calledparty.
After the circuit or channel has been set up, thencommunication will take place, then once they are throughthe channel will be cleared. This mechanism is referred to asbeing connection-oriented.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 14/68
Adva nt a ges of Cir cu it Sw itch ing
1. Once the circuit has been set up, communication isfast and without error.
2. It is highly reliable.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 15/68
D is adva nt a ges of Cir cu it Sw itch ing
1. Involves a lot of overhead, during channel set up.
2. Waists a lot of bandwidth, especial in speechwhereby a user is sometimes listening, and nottalking.
3. C hannel set up may take longer.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 16/68
P a cket Sw itch ing
P acket switching entails packaging data in speciallyformatted units (called packets ) that are typically routedfrom source to destination using network switches androuters.
Each packet contains address information that identifies thesending computer and intended recipient.
Using these addresses, network switches and routersdetermine how best to transfer the packet between hubs onthe path to its destination.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 17/68
Adva nt a ges of P a cket Sw itch ing
1. At the time of connection no need to worry aboutrouting.
2 Ability of route data units over any route. so morereliable.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 18/68
D is adva nt a ges of P a cket Sw itch ing
1. Less hard drive space needed but more actualmemory needed.
2. More processing power required due to complex
routing protocols. (Like recognizing when a packethas been lost).
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 19/68
M ess a ge Sw itch ing
In telecommunications, mess a ge sw itch ing wasthe precursor of packet switching, where messages
were routed in their entity, one hub at a time.
It was first introduced by Leonard Kleinrock in 1961.
Message switching systems are now a days mostlyimplemented over packet-switched or circuit-switched data networks.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 20/68
Adva nt a ges of M ess a ge Sw itch ing
1. The message are stored and relayed from secondarystorage (disk).
2. Mechanism a node receives a message stores ituntil the appropriate route is free, then sends italong.
3. Message switching sends data units that can be of any length.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 21/68
D is adva nt a ges of M ess a ge Sw itch ing
1. It's not suitable for real time applications such asdata communication, video or audio.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 22/68
NETWORK TOPO LOGY
Network topologies can be physical or logical.
P hysical topology means the physical design of a network including the devices, location andcable installation.
Logical topology refers to the fact that how dataactually transfers in a network as opposed to itsdesign.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 23/68
TYPES OF TOPO LOGI ES
1. Star Topology2. Ring Topology3. Bus Topology4. Mesh Topology5. Tree Topology6. Hybrid Topology
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 24/68
STAR TOPO LOGY
Part of LAN (Local AreaNetwork)
Used in home, office andbuilding
All devices connect to a centraldevice, called Hub.
C onnected with hub with theUTP(Unshielded Twisted Pair)
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 25/68
ADVANTAG ES OF STAR TOPO LOGY
Easy to install & wire.
Security can be implemented in the hub/ switch.
Easy to detect the fault and to remove parts.
No disruptions to the network then connecting orremoving devices.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 26/68
DISADVANTAG ES OF STAR TOPO LOGY
Requires more cable length than a linear or bustopology.
If the hub or connecter fails, nodes attached aredisabled.
More expensive than linear bus topologies becauseof the cost concentrators.
No privacy in the network.prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 27/68
RI NG TOPO LOGY
C able forms closed ring orloop, with all computers &devices arranged along ring.
Data travels from device todevice around entire ring, in onedirection.
Primarily is used for LANs, butalso is used in WANs (Wide AreaNetworks).
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 28/68
ADVANTAG ES OF RI NG TOPO LOGY
Growth of system has minimal impact onperformance.All stations have equal access.The network doesn t fail even when a link betweentwo nodes is broken.Data is quickly transferred without a bottle neck .
The transmission of data is relatively simple aspackets travel in one direction only.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 29/68
DISADVANTAG ES OF RI NG TOPO LOGY
Most expensive topology.
Failure of one computer may impact others.
It is difficult to troubleshoot the ring.
Data packets must pass through every computerbetween the sender & recipient therefore, thismakes it slower.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 30/68
BU S TOPO LOGY
It is also known as multipointtopology.
All computers & devicesconnected to central cable orhub.
C onsists of a main run of cable with a terminator eachend.
Popular on LANs becausethey are inexpensive & easy toinstall.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 31/68
ADVANTAG ES OF BU S TOPO LOGY
Easy to connect a computer or peripheral to a linearbus.
Requires less cable length than a star topology.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 32/68
DISADVANTAG ES OF BU S TOPO LOGY
Entire network shuts down if there is a break in themain cable.Terminators are required at both ends of thebackbone cables.Difficult to identify the problem if the entirenetwork shuts down.
Not meant to be used as a stand-alone solution in alarge building.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 33/68
M ESH TOPOLOGY
It requires that every terminal shouldbe attached to each other.
All the computers must haveadequate number of interfaces for theconnection to be made.
Because of this requirement theinstallation is somewhat difficult.
The length of cable required is alsoquiet high as compared with othertopologies.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 34/68
ADVANTAG ES OF M ESH TOPOLOGY
System provides increased reliability as well as easeof troubleshooting.
Data transfer is faster.
Addition and deletion of nodes easy.
Easy fault identification and isolation.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 35/68
DISADVANTAG ES OF M ESH TOPOLOGY
System is expensive to install because it uses a lot of cabling.
Difficult to installation & configuration.
More input & output nodes.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 36/68
TR EE TOPOLOGY
Server
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 37/68
TR EE TOPOLOGY
A tree topology combines characteristics of linearbus and star topologies.Only the devices can connect directly with the treebus.Each hub functions as a root of a tree of the networkdevices.
This bus/star/hybrid combination supports futureexpandability of the computer networks, muchbetter than a bus or star.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 38/68
ADVANTAG ES OF TR EE TOPOLOGY
Point-to-point writing for individual segments.
The network dosen t fail even when a link betweentwo nodes is broken.
Supported by several hardware & software venders.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 39/68
DISADVANTAG ES OF TR EE TOPOLOGY
Overall length of each segment is limited by thetype of cabling used.
If the backbone line breaks, the entire segmentgoes down.
More difficult to configure and wire than othertopologies.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 40/68
HYBRI D TOPO LOGY
A combination of any two or more networktopologies.Two star network are connected together exhibithybrid network topologies.For example :- If a department uses a bus network,second department uses the ring network, thirddepartment uses the mesh network and fourthdepartment uses the star network. All the networksof different types can be connected together througha central hub.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 41/68
Transmission Technology
There are two types of transmissiontechnology :-
1) Broadcast Networks
2) P oint to P oint Networks
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 42/68
B roadcast Networks
Single communication channel
P acket of data contains address of destination machine
Similar to railway announcementsystem
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 43/68
P o int to P o int Netwo r ks
Machines are connected pointto point
Data is routed from sourcemachine to target machine
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 44/68
INTER NETWORK S AND THE INTER NET
A collection of different networkconnected together
It is very large and available
world wide
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 45/68
Node 3 Node 1 Node 2
Router
WANRouter Router
Node 6 Node 5 Node 4
LAN
LAN
Fig : Internet work
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 46/68
INTERNETWORKS A ND THEINTERNET (cont.)
Accessing the Internet- You must have an account- You require a communicationsoftware
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 47/68
A set of rules according to which thecommunicating computers communicate.
The most common protocol used in networking isthe T C P
Protocols
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 48/68
File Transfer Protocol
The fundamental requirement is a commonprotocol.
The file transfer protocol gives the user anaccess to a remote machine file system.
The FTP is also an Internet tool.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 49/68
ELECTRONIC MAIL
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 50/68
Need for Electronic M ail
For fast and efficient method to exchangemessages and other data.
It allows a very easy merging of a particularmessage.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 51/68
Type of E-mail services
There are mainly 3 types of e-mail services.
1) POP Mail
2) Web-based E-mail
3) Mail Forwarding Services
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 52/68
POP M ail
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 53/68
Advantages of POP M ail
Work offline, compose or read messages.
Mail program used by our browser canbe configured to receive and send all oure-mail automatically.
Message can be easily accessible.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 54/68
Advantages of POP M ail (cont.)
Message can be automatically deletedfrom the server.
We can use powerful and intelligent e-mailsoftware.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 55/68
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 56/68
Web-based E-mail
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 57/68
Advantages of Web-based E-mail
Easy log in.
No need to configure any program.
No set up is required.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 58/68
Disadvantages of Web-based E-mail
It is time consuming.
Installation of latest web browsers are needed.
Most web-based services cannot match thefunctionality of a good e-mail package.
Advertising banners rotate, when we read ouremail.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 59/68
M ail Forwarding Services
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 60/68
Advantages of M ail Forwarding Services
It will help to continue the use of our existinge-mail account given by our ISP.
Forwarding services let us choose amemorable or fun name.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 61/68
Disadvantages of M ail Forwarding Services
It puts another layer between the sender andthe mail account.
Generally it is use to make money.
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 62/68
List of free POP M ail service providers
0 1. Amex Mail
0 2. C rosswinds
0 3. Newmail
04 . Peach World Network
05 . POPaccountprince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 63/68
List of free POP M ail service providers (cont.)
06 . SoftHome
07 . ForFree
08 . Freemail
09 . Friendly E-mail
10 . HotPop
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 64/68
Web based E-mail
MrPost
MyOwn E-mail
Muslim E-mail
GhanaMail
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 65/68
Web based E-mail (cont.)
gurlmail
HotMail
Eudora Web-Mail
Fastermail.com
123india.com
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 66/68
M ail forwarding services
Easy To
FlashMail
Grabmail
IName
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 67/68
M ail forwarding services (cont.)
NetForward
Nederlands.com
USA.NET
Bigfoot
Bitmail
prince dudhatra-9724949948
8/7/2019 Computer Networks Prince Dudhatra 9724949948
http://slidepdf.com/reader/full/computer-networks-prince-dudhatra-9724949948 68/68
THANK YOU THANK YOU
top related