Upload
mahon
View
50
Download
0
Embed Size (px)
DESCRIPTION
Navpreet Singh. COMPUTER NETWORK ARCHITECTURES. Computer Centre Indian Institute of Technology Kanpur Kanpur INDIA (Ph : 2597371, Email : [email protected]). Content. Content. Introduction to Computer Networks Overview Of Network Architectures Campus Networks Residential Networks - PowerPoint PPT Presentation
Citation preview
COMPUTER NETWORK ARCHITECTURES
Navpreet Singh
Computer CentreIndian Institute of Technology Kanpur
Kanpur INDIA
(Ph : 2597371, Email : [email protected])
Content
Content
Introduction to Computer Networks
Overview Of Network Architectures
Campus Networks
Residential Networks
Enterprise Networks
Internet
How Web Works
Network & Internet Security
Computer Networks
Computer network connects two or more autonomous computers.
The computers can be geographically located anywhere.
Introduction to Computer Networks
LAN, MAN & WAN
Introduction to Computer Networks
Network in small geographical Area (Room, Building or a Campus) is called LAN (Local Area Network)
Network in a City is call MAN (Metropolitan Area Network)
Network spread geographically (Country or across Globe) is called WAN (Wide Area Network)
Applications of Networks
Introduction to Computer Networks
Resource SharingHardware (computing resources, disks, printers)Software (application software)
Information SharingEasy accessibility from anywhere (files, databases)Search Capability (WWW)
CommunicationEmail, Chat, VoIPMessage broadcast
Remote computing
Distributed processing (GRID Computing)
Network Components
Introduction to Computer Networks
Physical Media
Interconnecting Devices
Computers
Networking Software
Applications
Networking Media
Networking media can be defined simply as the means by which signals (data) are sent from one computer to another (either by cable or wireless means).
Introduction to Computer Networks
Networking Devices
Introduction to Computer Networks
HUB, Switches, Routers, Wireless Access Points, Modems etc.
Computers: Clients and ServersIn a client/server network arrangement, network services are located in a dedicated computer whose only function is to respond to the requests of clients.
The server contains the file, print, application, security, and other services in a central computer that is continuously available to respond to client requests.
Introduction to Computer Networks
Networking Protocol: TCP/IP
Introduction to Computer Networks
Applications
E-mailSearchable Data (Web Sites)E-CommerceNews GroupsInternet Telephony (VoIP)Video ConferencingChat GroupsInstant Messengers Internet Radio
Introduction to Computer Networks
Campus LAN Technology OptionsEthernet
Fast Ethernet
Gigabit Ethernet
10 Gig Ethernet
WLAN
Campus Networks
Campus Network Architecture
Campus Network
Internet
Server Farm
Backbone Switch
Access Switch
Distribution Switch
RouterFirewall
Campus Network ArchitectureUses Three Tier Switching Architecture (Popularly known as Cisco’s Switching Architecture)Backbone Switch
Layer 3/4 Chassis based switchMultiple 100Fx or 1000SX/LX or 10GLX/LH ports for connectivity to Distribution switchesMultiple 10/100/1000 ports for connectivity to Servers
Distribution SwitchLayer 2/3 Managed Fixed configuration switch1/2 100Fx or 1000Sx/Lx or 10GLX/LH ports for connectivity to the Backbone switchMultiple 10/100 or 10/100/1000 ports for connectivity to the Access switches
Access SwitchLayer2 Managed/Unmanaged Fixed configuration switchMultiple 10/100 or 10/100/1000 ports for desktop connectivity
Campus Network
Residential Networks: Dial-upUses POTS (Plain Old Telephone System)
Provides a low cost need based access.
Bandwidth 33.6 /56 Kbps.
On the Customer End: Modem is connected to a Telephone Line
On the Service Provider End: Remote Access Server (RAS) is connected to Telephone Lines (33.6 Kbps connectivity) or E1/R2 Line (56 Kbps connectivity)
RAS provide dialin connectivity, authentication and metering.
Achievable bandwidth depends on the line quality.
MAN Technologies
Residential Networks: Dial-up
MAN Technologies
RAS
Residential Networks: DSLDigital Subscriber Line (DSL) uses the Ordinary Telephone line and is an always-on technology. This means there is no need to dial up each time to connect to the Internet.
Because DSL is highly dependent upon noise levels, a subscriber cannot be any more than 5.5 kilometers (2-3 miles) from the DSL Exchange
Service can be symmetric, in which downstream and upstream speeds are identical, or asymmetric in which downstream speed is faster than upstream speed.
DSL comes in several varieties:Asymmetric DSL (ADSL)High Data Rate DSL (HDSL) Symmetric DSL (SDSL) Very High Data Rate DSL (VDSL)
MAN Technologies
Residential Broadband: ADSL
MAN Technologies
Residential Broadband: Mobile Wireless
MAN Technologies
Use CDMA (128 Kbps) or GSM GPRS (384 Kbps) Mobile Wireless
Enterprise WAN Network
Enterprise Network
Enterprise WAN Network
Enterprise Network
Enterprise WAN Network
Enterprise Network
Server Farm
Service Provider Network
All the locations are connected through a Service Provider Networkover MPLS Backbone
Branch Office
Branch Office
Branch Office
Corporate Head Office
Internet
Internet
• Customers connect to a National ISP
• National ISPs connect to International Backbone Networks
BackboneISP Networks
ISP networ
k
ISP networ
k
ISPnetwork
Customer Networks
Bandwidth-limitedlinks
Service Provider Networks: Reliance
Service Provider Network
Service Provider Networks: RelianceReliance Data Centers, are connected to 132 countries across 4 continents spanning US, UK, Mid-east and Asia-Pac through Flag Telecom backbone (Reliance Infocomm 's group company) and other undersea cable systems like Se-Me-Wea-3 and i2i and are having public / private peering relationship with large Tier 1 ISPs and content providers at more than 15 Internet Exchange points across the globe. There also exists peering relationship with other popular domestic ISPs on STM-1 bandwidth levels.
The data centers further are connected to Reliance's country wide optic fiber based IP network with terabytes of capacity having points of presence at more than 1100 cities. Customers' can access the Internet by connecting to any of these 1100 PoPs using multiple means like local dedicated leased lines, PSTN -ISDN dialup links OR simply by using Reliance's 3G CDMA mobile services.
The Reliance Data Centers at various locations are also interconnected through redundant fiber ring with bandwidth capacity of STM-4 for data replication purposes for providing Disaster Recovery services.
Service Provider Network
Service Provider Networks: FLAG
Service Provider Network
Service ProvidersNational Service Providers:
VSNL
Reliance
BSNL
Bharti
Satyam
International Service Providers (connecting India to the World)
Flag
SingTel
NIXI (STPI Delhi, Mumbai, Kolkata & Chennai) provides peering connectivity between Indian ISPs
Service Provider Network
How Web Works?Let's say you want to visit the google website.
First you enter the address or URL of the website in your web browser.
Then your browser requests the DNS Server to get the IP address of the web server
WWW
How Web Works?Then your machine sends an HTTP request to the web server that hosts the google site.
The server sends the data over the Internet to your computer.
Your web browser interprets the data, displaying it on your computer screen.
WWW
DNS Resolution
DNS
DNS is a network service that enables clients to resolve names to IP address.
A DNS server maintains the name to IP address mapping of the domain for which it is the name server
The DNS server for a domain is registered with the domain registrar and the entry is maintained by the root-servers.
Whenever a DNS for a server is queried, the root servers are contacted.
The root servers replies with the IP address of the DNS server of the domain (for higher level domains) or forwards the request to the country root servers (four country specific domains).
Load Balancing
DNS
DNS supports Load Balancing: The same name resolves to multiple IP Addresses (IP addresses of different Mirrored servers).
Companies like akamai provide "Enhanced DNS" services:
Different DNS results based on source IP.
Web browser could automatically be directed to the closest web server thus reducing the download time
Companies like akamai maintain mirror sites of many organizations on their server and direct request for these sites to the nearest server.
INTERNET Security
INTERNET SECURITY
INTERNET Security ThreatsHacking
DoS
Reconnaissance
Malwares
Mail SPAM
Phishing
Botnets
INTERNET Security
Prevention TechniquesSome of the prevention tools include:
Network Firewall
Host Firewall
IDS/IPS
Mail Antispam and Antivirus Appliances
UTM Appliances
Application and OS Hardening
INTERNET Security
WLAN Security
INTERNET Security