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PUNJAB EDUSAT SOCIETY,CHD 1
SHARING OF DEVICES ON NETWORK
PRESENTATION BY:MAMTA
LECT. COMPUTER ENGG.GPC KHUNIMAJRA(MOHALI)
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OUTLINE OF THE LECTURE
• Introduction: Sharing Resources• Device server• Printer server• Terminal server• Resource sharing• IP Addresses• Two-tier architecture• Three-tier architecture
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INTRODUCTION
A shared resource or network share is a device or piece of information on a computer that can be remotely accessed from another computer, typically via a local area network . Examples are shared file access , shared printer access, shared scanner access etc. The shared resource is called a shared disk, shared drive, shared folder, shared file, shared printer or shared scanner. The term file sharing means shared file access, especially in the context of operating systems and LAN .
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Shared file and printer access require an operating system on the client that supports access to resources on a server, an operating system on the server that supports access to its resources from a client, and an application layer file sharing protocol and transport layer protocol to provide that shared access. Modern operating systems for personal computers include distributed file systems that support file sharing, while hand-held computing devices sometimes require additional software for shared file access.
SHARING RESOURCES
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SHARING RESOURCES
Sharing of resources over network
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SHARING RESOURCES
Sharing of resources over network
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SHARING DISKS AND FILES
Resource Sharing between computers is passing files from one computer to another. This method places severe limits on the volume of data, as well as the speed and distance in which it can be shared. Another technique for resource sharing is to directly connect two computers together by means of a cable link between (COM) ports of each computer. Figure shows two computers connected through their COM ports.
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SHARING DISKS AND FILES
Direct connection between two computers
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• Communication software is required for each computer in order to make use of the physical connection between the computers. You must configure one computer as a host or server and one as a client. The client computer will then have access to data on the host. Direct cable connections are most often used to share files between a desktop computer and a laptop computer.
• In a network environment with many users and job requirements permissions need to be established. These allow specific network users to access information while blocking unwelcome access to confidential or valuable data.
SHARING DISKS AND FILES
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SHARING DISKS AND FILES
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SHARING IN A PEER-TO-PEER ENVIRONMENT
The simplest method of networking is peer-to-peer. In this networking environment, data sharing occurs at the drive or folder level. Any drive or folder on a drive can be shared. Each computer shares its drive or folder resources to the network and each user is responsible for setting the shares. The user can also choose to share printer resources.
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SHARING IN A PEER-TO-PEER ENVIRONMENT
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SHARING IN A PEER-TO-PEER ENVIRONMENT
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SOFTWAREIn order to share on a peer-to-peer network, file and print sharing must first be enabled on the computer. Each OS has its own methods for enabling sharing. SHARING PRINTERS, DRIVES AND FOLDERSAfter sharing has been enabled you can decide which drives, folders and printers to make available to the network. Sharing options include hard drives, CD-ROM drives, floppy-disk drives, and folders. (Devices such as scanners and modems cannot be shared.)
SHARING IN A PEER-TO-PEER ENVIRONMENT
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FILE SHARINGThe term file sharing means shared file access, especially in the context of operating systems and LAN and Internet services, for example in Microsoft Windows documentation. Shared file and printer access within a local area network may either be based on a centralized (client server) paradigm or on a decentralized(peer to peer) model.
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In client server communications, a client process on the local user computer takes the initiatives to start the communication, while a server process on the file server or print server remote computer waits for the requests to start a communication session. In peer to peer network, any computer can be a server as well as a client .
FILE SHARING
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THREE TYPES OF SERVERS
• Device Server• Printer Server• Terminal Server
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DEVICE SERVERA device server is a closed box that provides extreme ease of installation, minimal maintenance and can be managed by client remotely via a web browser. It is a device or service that provides access to the system console. It provides a number of serial ports which are then connected to the serial ports of other equipment such as servers, routers or switches. The consoles of connected devices can be accessed by connecting to the console server over a serial link such as modem or over a network such as telnet.
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DEVICE SERVER
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DEVICE SERVER
DB9 ETHERNET DEVICE SERVER
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A print server or printer server is a device that connects printers to client computers over a network. It accepts print jobs from the computers and sends the jobs to the appropriate printers, queuing the jobs locally. Its functions include the ability to inspect the queue of jobs to be processed, the ability to reorder or delete waiting print jobs or the ability to do various kinds of accounting (such as counting pages of printer).
PRINTER SERVER
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PRINTER SERVER• Print servers may support a variety of industry-standard
or printing protocols including Internet Printing Protocol, Line Printer Daemon protocol, NetWare, NetBIOS orJetDirect.
• A print server may be a networked computer with one or more shared printers. Alternatively a print server may be a dedicated device on the network with connections to the LAN and one or more printers. Dedicated server appliances tend to be fairly simple in both configuration and features.A printer may have a built-in print server.
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PRINTER SERVER
A wireless print server
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An example of network printing 4/11/2013
PRINTER SERVER
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TERMINAL SERVERA terminal server/serial server/ network access server enables organizations to connect devices with an RS-232, RS-422 or RS-485 serial interface to a LAN. Terminal servers can be very simple devices that do not offer any security functionality, such as data encryption and user authentication. There are many terminal servers on the market that have highly advanced security functionality to ensure that only qualified personnel can access various servers and that any data that is transmitted across the LAN, or over the Internet, is encrypted.
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TERMINAL SERVER
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TERMINAL SERVER
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WHAT IS WIN PROXY?
It is the tool which provides various facilities, applications and information in a network shared environment. It is world’s first proxy server and the firewall with integrated mail server for windows. It allows you to connect your entire local network to the internet through one IP address.
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• It combines the advantages of proxy server and the network address translation technologies into one level and establishes connections when required and logging off when service is no longer required.
• It is easy to use and install software package that combines the latest internet connection sharing technology.
• It runs on the single windows 95/98 NP, XP based PC and supports any LAN including wireless connections.
WHAT IS WIN PROXY?
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WHAT IS WIN PROXY?
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WHAT IS WIN PROXY?
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FEATURES OF WIN PROXY
Internet access through Win Proxy is easy for network's users .
It supports HTTP, FTP, Telnet, GOPHER, NNTP, SMTP, POP3 etc protocols and allows centralized anti-virus control of emails.
It allows shared cache, dial on demand, logging user management etc and eliminates the complexity and expense of maintaining multiple phone lines modems and user accounts for each individual connection as required.
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WINPROXY SETUP• Many software applications don't require much
in the way of preparation: you just pop in a CD-ROM and, after a couple of mouse clicks, you're on your way. If you already have a functioning TCP/IP network, Win Proxy's installation can be just that easy.
• This section tells you what needs to be done-and, when appropriate, shows you how to do it-before installing Win Proxy.
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There are seven categories of preparation, but you've probably already met the requirements in at least a few of them. The categories are:• System Requirements• Internet Connection• Internet Service• Network Hardware• Addressing Information• TCP/IP Protocol• Your Win Proxy Serial Number• Anti-Virus and Site-Filtering Serial Numbers
WINPROXY SETUP
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SYSTEM REQUIREMENTS
To run Win Proxy, your system must be an IBM/PC or compatible computer running Windows 95/98/NT/2000/ Me/XP with at least a 90 MHz processor chip. While the application itself uses only a small amount of disk space, 32 megabytes of disk space is recommended.
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INTERNET CONNECTION
You'll need one modem (or cable modem) on the Win Proxy computer. Any Internet connection that uses TCP/IP works, including ISDN and wireless.
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INTERNET SERVICEInternet Service Providers or ISPs provide access to the Internet and to mail and news servers. ISPs can be large and nationwide like Netcom or WorldNet or they can be small and local. A user account from any Internet Service Provider is needed to access the Internet once Win Proxy is running. You'll need only one account, since, by using Win Proxy, all computers on your network can gain Internet access through the same account.
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NETWORKS HARDWAREThe exact kind of network hardware you use depends on the kind of access you have to the Internet.• Dial-Up Access. If you're using a modem, you must use
dial-up access. You'll also need one network hub and a cable for each computer connecting to that hub.
• Cable Modem/ADSL Modem/Direct Access. Each computer needs an installed and operational network card, as well as one additional card for the Win Proxy computer (for connection to the Internet). You'll also need a hub if you have more than two computers, and a cable for each computer connecting to the hub.
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ADDRESSING INFORMATION
• Computers need addresses to which various kinds of data can be sent. The reason: that particular configuration allows Win Proxy to determine all addresses for you.
• If you'll be using the more advanced setups, you may need to provide certain addressing information to Win Proxy, including any of the following: ISP news servers, mail servers, pop servers, and DNS servers.
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TCP/IP PROTOCOL
TCP/IP is the Internet's protocol which allows computers to communicate. All communication between the Win Proxy computer, clients, and the Internet use the TCP/IP protocol. The TCP/ IP protocol capability is supplied as part of the standard installation of Microsoft Windows 98/NT/2000/Me/XP.
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WINPROXY SERIAL NUMBER
• When you download a trial version of Win Proxy, you have full use of the program and all of its features for a 30-day trial. At the end of thirty days Win Proxy becomes unresponsive except for the menu, which allows you to enter a serial number.
• You can enter a serial number at any time. When you do, the copy of Win Proxy you have downloaded returns to full functionality.
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ANTI-VIRUS AND SITE-FILTERING SERIAL NUMBERS
• The Anti-Virus and Site-Filtering options are also operational during the 30-day trial period. When you purchase and install a Win Proxy serial number, the Anti-Virus and Site-Filtering options are automatically enabled for a 6-month period. If you purchase and install an extension before your previous period has expired, the new extension is added onto the existing period.
• After the initial 6-month period, these features will be disabled unless you purchase the extensions.
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WINPROXY COMPUTER PRE-INSTALLATION CHECKLIST
CATEGORY REQUIREMENTWinProxy PC IBM PC/compatible computerProcessor 90MHz Pentium or betterOperating System Windows 95/98/NT/2000/Me/XP
Disk Space Needed 32MB RAM 3 MB for WinProxy software 3 MB for anti-virus program 10 MB for optimal caching 10 MB for site filtering
Internet Connection (WinProxy Computer Only)
One modem or other connecting device (cable modem, DSL, ISDN, T1-T3, frame relay, wireless)
Internet Service One user account through an Internet Service Provider
Network Hardware
Clients: 1 Network Interface Card (NIC) each. Servers: 1 LAN connection NIC or equiv); 1 Internet connection (dial-up adapter or another NIC). Optional hub and cables depending on network configuration.
TCP/IP Protocol The TCP/IP protocol that is standard in Windows and NT will do just fine
WinProxy Serial Obtained at time of purchase, not needed for 30-day trial period.
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WHAT IS AN IP ADDRESS? • An IP address is a unique global address for a
network interface• Exceptions:
– Dynamically assigned IP addresses ( DHCP, Lab 7)– IP addresses in private networks ( NAT, Lab 7)
• An IP address:- is a 32 bit long identifier.- encodes a network number (network prefix) and a host number.
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IP ADDRESSES
An Internet Protocol address (IP address) is a numerical label assigned to each device (e.g., computer, printer) participating in a computer network that uses the Internet Protocol for communication.An IP address serves two principal functions: host or network interface identification and location addressing. Its role has been characterized as follows: "A name indicates what we seek. An address indicates where it is. A route indicates how to get there."
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IP ADDRESSES
Application dataTCP HeaderEthernet Header Ethernet Trailer
Ethernet frame
IP Header
version(4 bits)
headerlength
Type of Service/TOS(8 bits)
Total Length (in bytes)(16 bits)
Identification (16 bits)flags
(3 bits)Fragment Offset (13 bits)
Source IP address (32 bits)
Destination IP address (32 bits)
TTL Time-to-Live(8 bits)
Protocol(8 bits)
Header Checksum (16 bits)
32 bits
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• The network prefix identifies a network and the host number identifies a specific host (actually, interface on the network).
• How do we know how long the network prefix is? – Before 1993: The network prefix is implicitly defined.or– After 1993: The network prefix is indicated by a
netmask.
NETWORK PREFIX AND HOST NUMBER
network prefix host number
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IP VERSIONS
Two versions of the Internet Protocol (IP) are in use: IP Version 4 and IP Version 6. Each version defines an IP address differently. Because of its prevalence, the generic term IP address typically still refers to the addresses defined by IPv4.
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IPV4 ADDRESSES• In IPv4 an address consists of 32 bits which limits the
address space to 4294967296 (232) possible unique addresses. IPv4 reserves some addresses for special purposes such as private networks (~18 million addresses) or multicast addresses (~270 million addresses).
• IPv4 addresses are canonically in dot-decimal notation, which consists of four decimal numbers, each ranging from 0 to 255, separated by dots, e.g., 172.16.254.1. Each part represents a group of 8 bits (octet) of the address. In some cases of technical writing, IPv4 addresses may be presented in various hexadecimal, octal, or binary representations.
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DOTTED DECIMAL NOTATION• IP addresses are written in a so-called dotted
decimal notation.• Each byte is identified by a decimal number in
the range [0..255]:
• Example:
1000111110000000 10001001 10010000
1st Byte
= 128
2nd Byte
= 143
3rd Byte
= 137
4th Byte
= 144
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• Example:
• Network address is: 128.143.0.0 (or 128.143)
• Host number is: 137.144• Netmask is: 255.255.0.0 (or ffff0000)
• Prefix notation: 128.143.137.144/16» Network prefix is 16 bits long
EXAMPLE
128.143 137.144
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SPECIAL IP ADDRESSES• Reserved or (by convention) special
addresses: Loopback interfaces – all addresses 127.0.0.1-127.255.255.255 are
reserved for loopback interfaces.– Most systems use 127.0.0.1 as loopback address.IP address of a network o Host number is set to all zeros, e.g., 128.143.0.0 Broadcast address Host number is all ones, e.g., 128.143.255.255 Broadcast goes to all hosts on the network
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Subnetting
SUBNETTING• Problem: Organizations
have multiple networks which are independently managed – Solution 1: Allocate a separate
network address for each network• Difficult to manage• From the outside of the
organization, each network must be addressable.
– Solution 2: Add another level of hierarchy to the IP addressing structure
University NetworkUniversity Network
Medical School
Library
EngineeringSchool
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• Each part of the organization is allocated a range of IP addresses (subnets or subnetworks).
• Addresses in each subnet can be administered locally.
ADDRESS ASSIGNMENT WITH SUBNETTING
University NetworkUniversity Network
Medical School
Library
EngineeringSchool
128.143.0.0/16
128.143.71.0/24128.143.136.0/24
128.143.56.0/24
128.143.121.0/24
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BASIC IDEA OF SUBNETTING• Split the host number portion of an IP address into a subnet number and a (smaller) host number.
• Result is a 3-layer hierarchy.
• Then: • Subnets can be freely assigned within the organization.• Internally, subnets are treated as separate networks.• Subnet structure is not visible outside the organization.
network prefix host number
subnet numbernetwork prefix host number
extended network prefix
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• Routers and hosts use an extended network prefix (subnetmask) to identify the start of the host numbers
SUBNETMASK
128.143 137.144
network prefix host number
128.143 144
network prefix host numbersubnetnumber
137
extended network prefix
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0
subnetmask
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ADVANTAGES OF SUBNETTING• With subnetting, IP addresses use a 3-layer hierarchy:
» Network » Subnet» Host
• Reduces router complexity. Since external routers do not know about subnetting, the complexity of routing tables at external routers is reduced.
• Note: Length of the subnet mask need not be identical at all subnetworks.
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CLASSFULL IP ADRESSES (UNTIL 1993)
• When Internet addresses were standardized (early 1980s), the Internet address space was divided up into classes:– Class A: Network prefix is 8 bits long
– Class B: Network prefix is 16 bits long
– Class C: Network prefix is 24 bits long
• Each IP address contained a key which identifies the class:– Class A: IP address starts with “0”
– Class B: IP address starts with “10”
– Class C: IP address starts with “110”
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OLD WAY: INTERNET ADDRESS CLASSES
Class C network id host11 0
Network Prefix24 bits
Host Number8 bits
bit # 0 1 23 242 313
Class B 1 network id host
bit # 0 1 15 162
Network Prefix16 bits
Host Number16 bits
031
Class A 0Network Prefix
8 bits
bit # 0 1 7 8
Host Number24 bits
31
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Class D multicast group id11 1bit # 0 1 2 313
04
Class E (reserved for future use)11 1bit # 0 1 2 313
14
05
OLD WAY: INTERNET ADDRESS CLASSES
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IPV6 - IP VERSION 6• IP Version 6
– Is the successor to the currently used IPv4. – Specification completed in 1994.– Makes improvements to IPv4 (no revolutionary
changes).
• One feature of IPv6 is a significant increase in no. of the IP address to 128 bits (16 bytes)
• IPv6 will solve the problems with IP addressing.• 1024 addresses per square inch on the surface of the Earth.
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IPv6 Header
Application dataTCP HeaderEthernet Header Ethernet Trailer
Ethernet frame
IPv6 Header
version(4 bits)
Traffic Class(8 bits)
Flow Label(24 bits)
Payload Length (16 bits)Next Header
(8 bits)Hop Limits (8 bits)
Source IP address (128 bits)
32 bits
Destination IP address (128 bits)
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IPV6 VS. IPV4: ADDRESS COMPARISON
• IPv4 has a maximum of 232 4 billion addresses
• IPv6 has a maximum of 2128 = (232)4 4 billion x 4 billion x 4 billion x
4 billion addresses
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IP ADDRESS MANAGEMENTInternet Protocol address management (IPAM) is a means of planning, tracking, and managing the Internet Protocol address space used in a network. . IPAM tools are increasingly important as new IPv6 networks are deployed with larger address pools, different subnetting techniques, and more complex 128-bit hexadecimal numbers which are not as easily human-readable as IPv4 addresses.IPv6 networking, mobile computing, and multihoming require more dynamic address management and are causing technical obsolescence of the early generations of IP address management (IPAM) software and spreadsheets used for address management.
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CLIENT/SERVER ARCHITECTURE
• Database server to replace File server.• Query based approach.• Reduced traffic, since required
content is only transferred.• Improves multi-user updating.
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2-TIER ARCHITECTURE
2-tier architecture is used to describe client/server systems where the client requests resources and the server responds directly to the request, using its own resources. This means that the server does not call on another application in order to provide part of the service.
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2-TIER ARCHITECTURE
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TWO-TIER ARCHITECTURE
• Example of C/S Architecture.• Improves scalability over File Sharing
Architecture.• Consists of 3 components
– User system interface.– Processing Management.– Database Management.
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TWO TIER ARCHITECTURE
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TWO-TIER ARCHITECTURE
Limitations– Performance deteriorates if number of users
is greater than 100.– Restricted flexibility and choice of DBMS,
since data language used in server is proprietary to each vendor.
– Limited functionality in moving program functionality across servers.
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THREE-TIER ARCHITECTURE
• To overcome the limitations of Two-Tier Architecture.
• Middle tier between UI and DB.• Ways of incorporating Middle-Tier
– Transaction processing Monitors.– Application Servers.– Message Servers.
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3-TIER WITH A TP MONITOR
• Online access through– Time sharing or Transaction Processing.
• Client connects to TP instead of DB.• Monitor accepts transaction, queues it and
takes responsibility until it is completed.• Asynchrony is achieved.
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3-TIER WITH A TP MONITOR
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3-TIER ARCHITECTURE
• In 3-tier architecture, there is an intermediary level, meaning the architecture is generally split up between:
• A client, i.e. the computer, which requests the resources, equipped with a user interface (usually a web browser) for presentation purposes.
• The application server (also called middleware), whose task it is to provide the requested resources, but by calling on another server.
• The data server, which provides the application server with the data it requires.4/11/2013
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3-TIER ARCHITECTURE
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COMPARING BOTH TYPES OF ARCHITECTURE
• 2-tier architecture is therefore a client-server architecture where the server is versatile, i.e. it is capable of directly responding to all of the client's resource requests.
• In 3-tier architecture however, the server-level applications are remote from one another, i.e. each server is specialized with a certain task (for example: web server/database server). 3-tier architecture provides:
• A greater degree of flexibility.• Increased security, as security can be defined for each service
and at each level.• Increased performance, as tasks are shared between servers.
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THANK YOU