Basics of Internet 1 1 Terminology Internet A

Basics of Internet 1 1

Terminology Internet : - A "network of networks" linking millions of computers worldwide for communications purposes. The Internet was originally developed in 1969 for the U. S. military and gradually grew to include educational and research institutions. ISP : - ISP stands for Internet Service Provider, an ISP is a company that provides access to the Internet WWW : - Stands for "World Wide Web"; the large global collection of Internet servers which support hypertext documents coded in HTML, and transferred via HTTP. URL : - (Uniform Resource Locator) is a way of addressing used for world wide web. An URL consist of the type of service (protocol), then the host name and then the file on the host PING : - Packet Internet Groper; a utility used to determine whether a particular computer is currently connected to the Internet. It works by sending a packet to the specified IP address and waiting for a reply as well as to check the response from the system to the server. Radius : - Short for Remote Authentication Dial-In User Service, an authentication and accounting system used by many Internet Service Providers (ISPs). When you dial in to the ISP you must enter your username and password. This information is passed to a RADIUS server, which checks that the information is correct, and then authorizes access to the ISP system 2 2

Terminology ADSL : - (Asymmetric Digital Subscriber Line) - A method for moving data over regular telephone lines that is much faster than a regular telephone connection. A common configuration of ADSL would allow a subscriber to download at speeds of up to 1. 544 megabits per second, and upload at speeds of up to 128 kilobits per second. A family of technologies used to deliver high-rate digital data over the existing copper local loop. One-way rates of up to 6 Mbps downstream (from the central office to the subscriber) and up to 640 kbps upstream have been achieved, although the technology is still evolving and higher data rates are expected in the future Bandwidth : - A measurement of the amount of data that can be transmitted over a network at any given time. The higher the network's bandwidth, the greater the volume of data that can be transmitted (Explained Further in Detail ). HOPS : - In computer networking, a hop represents one portion of the path between source and destination. When communicating over the Internet, for example, data passes through a number of intermediate devices (like routers) rather than flowing directly over a single wire. Each such device causes data to "hop" between one point-to-point network connection and another. Contention ratio: Contention ratio is the upper and the lower limit defined on the speed given to a subscriber as per his plan. This defines the lower limit below which the speed will never go and the upper limit of the speed that customer will get. For e. g. Contention ratio of Home 699 is 128 Kbs 1: 2. This means the speed will never be below 64 kbps and will go to max 128 kbps. Customer gets an average speed as per the contention ratio. 3 3

Online Presentation http: //www. learntcpip. com/Internet. Runs/Howthe. Internetruns_files/ Default. htm#nopreload=1&TOCEntry=1 4

What is Bandwidth? 5 5

DSL Speed Comparison 6 6

Units in Data Transmission Bits Per Second ( bps ) – Measure of Data speed in an second 1 Kbps 1 Mbps = = 1, 024 bps 1, 024 Kbps Computer modems for telephone line operates at app 57. 6 Kbps A web page on an average would be 40 to 50 Kilobytes in size 0/1 1 B 1 Kb 1 Mb 1 Gb = = = 1 bit 8 Bit 1, 024 Bits 1, 024 Kilobits 1, 024 Megabits 7 7

What is broadband? Broadband is the common term for a high bandwidth internet connection one that can send or download information many times faster than with a standard telephone and modem. You can do everything you want to do online more quickly and more easily with broadband: • • • Your internet access is always on. You don't have the trouble of dialing-up and logging-on each time you want to do something online. Run your business more efficiently and effectively. Work from home with high speed access to corporate networks and symmetric broadband services. You're always in touch with your customers and suppliers, friends and family are only a click away with email or instant messaging. Download complex and graphic-rich websites virtually instantly. Download music, animations and video clips faster than ever. Play interactive games at top speed against gamers around the world. Receive internet radio and other real time services without interruption. 8 8

Main Features of the Broadband/ ADSL Service • • High speed data download for Broadband Internet data speed starts from 64 kbps to 1 Mbps. Simultaneous availability of Phone and Internet on the existing Telephone line ”Always on Internet”. No Phone call charges for Internet access. 24 Hours Help line and Technical support on phone. Telephone will continue to work even in case of power failure at subscribers end. It will provide Multicast Video Services, Video-on-demand etc in future. Can share Broadband connection to create own LAN network i. e. more than one PC can be connected. Always on connectivity to Internet. 9 9

Broadband vs. Dialup Internet Connection The fundamental difference between dialup and broadband Internet connections is the manner in which the connection is made from your PC to the Internet. • • • A dialup service connects to the Internet through your phone line. The modem in your PC "calls" an Internet Service Provider (ISP) and connects with a maximum speed of 56, 000 bytes per second, better known as a 56 K speed connection. Each time your PC dials into the ISP, it is assigned an Internet Protocol (IP) address. A different, unique IP address is assigned at the beginning of each visit so that the ISP can recognize your PC and make sure you can send and receive data. The fact that your IP address constantly changes essentially makes your Internet connection more secure. In contrast, when you connect to the Internet via a broadband Internet connection, the process is slightly different. Once your PC is connected to the ISP through a cable or DSL connection. • • It remains connected until the cable box or DSL line is disconnected or physically unplugged. Broadband services are often referred to as "always on" services because it is not necessary to make a setup call to your ISP each time you wish to access the Internet; this means that once you are assigned an IP address, you keep it until you request it to be changed. We'll learn how to do this later. 10 10

Broadband vs. Dialup Internet Connection Speed DSL offers guaranteed speeds (symmetrical up to 1 Mbps or 35 times faster than 28. 8 Kbps analog modem). Dial-Up access offers speeds up to a maximum of only 56 Kbps. Flexibility DSL provides Internet access to multiple PCs/end-users on one single connection, thereby not charging extra for all additional PC/end-user access. DSL is a fully scalable service possessing a wide range of potential speeds that are inexpensive and easy to upgrade. Dial-Up access is capable of providing Internet access to only one PC/end-user, thereby charging extra for each additional PC/end-user access. Dial-Up access is not a scalable service due to its bandwidth limitations of 56 Kbps. Reliability DSL, by being dedicated, avoids disruptive and time consuming process of dialing in for Internet access. Dial-Up access is faced with the sometimes tedious process of dialing in for Internet access. Price DSL is priced on a flat monthly rate with no additional usage/toll charges. Dial-Up access can have costly per-monthly usage/toll charges in addition to Internet access. Dial-Up access must be provided with individual lines and modems for multiple end users to have simultaneous access. DSL can be cost-effectively divided among multiple end-users for simultaneous access on a single connection. 11 11

What is DSL ? DSL means Digital Subscriber Line. A method for moving data over regular phone lines. A DSL circuit is much faster than a regular phone connection, and the wires coming into the subscriber's premises are the same (copper) wires used for regular phone service. DSL is more reliable than dial-up due to broad band's digital nature and always on connectivity. With DSL , when you turn on your computer, you’re already connected to the Internet and ready to surf at high speeds. A DSL circuit must be configured to connect two specific locations, similar to a leased line (however a DSL circuit is not a leased line). DSL is now a popular alternative to Leased Lines and ISDN, being faster than ISDN and less costly than traditional Leased Lines. Technologies used by DSL ( A ) Symmetric DSL refers to DSL technologies which provide the same bandwidth upstream and downstream. E. g. like HDSL (High Bit Rate DSL), SDSL (Symmetric DSL). ( B ) Asymmetric DSL refers to DSL technologies, which provide higher downstream bandwidth while lower upstream bandwidth. e. g. ADSL ( C ) ISDN DSL refers IDSL is the "always on" cousin of dial-up ISDN. IDSL delivers a symmetric capacity of 144 Kbps. IDSL is offered primarily because of an extended range when compared to ADSL or SDSL. 12 12

How it works for you The ADSL connection is provided to you via the normal telephone cable from our nearest exchange. The cable from our exchange is combined along a main splitter and carried across normal lines of the exchange to your premises and terminated on to another splitter. This splitter separates the voice and data traffic simultaneously transmitting them to their respective destinations. As the transmission frequencies for data and voice are different on the bandwidth spectrum, there are no choking, interference, or disconnection problems faced by you. The splitter is connected onto your phone and the data line onto your ADSL Customer Premises Equipment (CPE), either a Digital USB modem or a Network modem as applicable. This kind of an exclusive connectivity facilitates you to speak and surf independently without having to bear huge telephone bills for browsing your favorite sites 13 13

DSL Frequency Spectrum ? 14 14

How Does it work ? DSL - a technology which transforms plain old telephone lines into a high speed conduit for data, information, entertainment and more. It utilizes more of the bandwidth on copper phone lines than what is currently used for plain old telephone service (POTS). The DSL technology uses the frequencies above the telephone bandwidth. Therefore on different frequencies one can make a voice call and be on the Internet simultaneously. Splitter is a device used to divide the data and voice separately making internet usage and voice calls work simultaneously. Frequency that analog uses is up to 4 k. Hz and dsl uses up to 1. 2 MHz. 15 15

Correct Wiring Diagram 16 16

What A Splitter Looks Like? 17 17

Correct Wiring Diagram in EPBAX Scenario 18 18

Network Diagram for Airtel BBNL SWITCH CHENNAI GR i 2 i VSNL LDAP y SINGTEL CISCO 7200 ROUTER a ew t ga ATM (1, 32) C A S C A D E ERX RADIUS PS CO SDX Switch Modem/Router Telco Cable B US ble Ca CPE MDF SDH DSLAM RJ 11 RSU / DLC Phone Computer Telco Cable Splitter RJ 11 DP SP P MDF DSL LINE 19 19

Basic Requirements of using DSL • Computer – Operating System – Win 98 SE (Minimum Standard) • Pentium II • 128 MB RAM • USB / LAN Port • Internet Explorer 6 or above and Cipher Strength 128 Bit Encryption Note - : 1. 2. USB Modem doesn’t support all Operating System ( For e. g. Mac , Linux , 2000 Server) 2. Ethernet Modem/Routers support all Operating Systems 3. Combo Modems support all OS. 20

Advantages/Limitation of DSL Advantages • • • Surf and talk on the phone at same time “ Always On” connection (No waiting to “dial in”) The speed is much faster than a regular modem (1. 5 Mbps vs. 56 Kbps) DSL’s speed is up to 50 times faster than a standard dial-up connection DSL doesn't necessarily require new wiring; it can use the touchtel phone line DSL is inherently more secure than cable connections In addition, with DSL each customer has a separate "Private Virtual Circuit, " a unique connection that authenticates and secures the comm. b/w the customer's PC and the Internet. DSL download speeds are not affected by the number of users DSL is generally more cost-effective that it is much cheaper as compared to any other connections used (that is for e. g. Lease Lines , ISDN , Cable Connections) DSL can be easily upgraded and downgraded as per speed requirements. Limitation • • DSL connection is faster when you are closer to your provider's central within a radius of 2. 5 KM. The connection is faster for receiving data than it is for sending data over the Internet. Depending on the type of DSL the user has, the download speed is faster than the upload speed. DSL is not available in all areas. 21 21

Types of Modem / Routers used Types of Modem / Routers Used by Airtel Beetel 220 BX Zyxel Prestige 600 Zyxel Prestige 630 Beetel Cx 100 Zyxel Router Speedstream Beetel Old Ethernet Modem RTS RB Comtech 22 22