These computers include the entire spectrum of PCs, through professional workstations upto super-computers. As the performance of computers has increased, so too has the demand for communication between all systems for exchanging data, or between central servers and the associated host computer system. The replacement of copper with fiber and the advancement sin digital communication and encoding are at the heart of several developments that will change the communication infrastructure. The former development has provided us with huge amount of transmission bandwidth. While the latter has made the transmission of all information including voice and video through a packet switched network possible.
With continuously work sharing over large distances, including international communication, the systems must be interconnected via wide area networks with increasing demands for higher bit rates.
For the first time, a single communications technology meets LAN and WAN requirements and handles a wide variety of current and emerging applications. ATM is the first technology to provide a common format for bursts of high speed data and the ebb and flow of the typical voice phone call. Seamless ATM networks provide desktop-to-desktop multimedia networking over single technology, high bandwidth, low latency network, removing the boundary between LAN WAN.
ATM is simply a Data Link Layer protocol. It is asynchronous in the sense that the recurrence of the cells containing information from an individual user is not necessarily periodic. It is the technology of choice for evolving B-ISDN (Board Integrated Services Digital Network), for next generation LANs and WANs. ATM supports transmission speeds of 155Mbits / sec. In the future. Photonic approaches have made the advent of ATM switches feasible, and an evolution towards an all packetized, unified, broadband telecommunications and data communication world based on ATM is taking place.
ATM does not stand for automatic teller machine. In the telecommunication, it stands for Asynchronous Transfer Mode, in which data sends asynchronously. This mode is another fast packet switching mode.
ATM is regarded as the technology of the 21st century and its impact is expected to be similar to PCM (pulse code modulation) which is used widely around the world in telecommunication.
Asynchronous transfer mode (ATM) is a technology that has his its history in the development of broadband ISDN in the 1970s and 980s. Technically, it can be viewed as an evolution of pocket switching. Like packet switching for data , ATM integrates the multiplexing and switching functions, is well suited for bursty traffic and allows communications between devices that operate at different speeds . Unlike packet switching , ATM is designed for high-performance multimedia networking.
ATM is also a set of international interface and signaling standards defined by the International Telecommunication Union- Telecommunications (ITU-T) Standards Sector (formerly the CCITT). The ATM forum has played a pivotal role in the ATM market since its formulation in 1991.
The ATM forum is an international voluntary organization composed of vendors , service providers, research organization, and users. Its purpose is to accelerate the use of ATM products and services through the rapid convergence of interoperability specifications, promotion of industry cooperation , and other activities. Developing multivendor implementation agreements also furthers this goal.
What is ATM ?
Asynchronous transfer mode is a high speed; packet based multiplexing technique in which information flow is organized in short fixed length cells.
The cells are generated when there is new data to send, which allows an element of data compression (e.g there is no need to send the pauses that occurs in speech). It also means that cells with different bandwidth in each direction are possible- a fax connection, for example uses little bandwidth in return direction. This allows more efficient use of the network resourses.
ATM provides a way of multiplexing many sources of data onto a common cells stream. Regardless of speed of the inputs. This greatly improves flexibility, enabling provision of bandwidth on demand.
Asynchronous Transfer Mode Switching
Asynchronous Transfer Mode (ATM) an International Telecommunication Union-Telecommunications Standards Section (ITU-T) standard for cell relay wherein information for multiple service types, such as voice, video, or data, is conveyed in small, fixed-size cells. ATM networks are connection-oriented. This chapter provides summaries of ATM protocols, services, and operation. Figure illustrates a private ATM network and a public ATM network carrying voice, video, and data traffic.
ATM is based on the efforts of the ITU-T Broadband Integrated Services Digital Network (B-ISDN) standard. It was originally conceived as a high-speed transfer technology for voice, video, and data over public networks. The ATM Forum extended the ITU-T's vision of ATM for use over public and private networks. The ATM Forum has released work on the following specifications:
User-to-Network Interface (UNI) 2.0
Public-Network Node Interface (P-NNI)
LAN Emulation (LANE)
Multiprotocol over ATM
ATM Devices and the Network Environment
ATM is a cell-switching and multiplexing technology that combines the benefits of circuit switching (guaranteed capacity and constant transmission delay) with those of packet switching (flexibility and efficiency for intermittent traffic). It provides scalable bandwidth from a few megabits per second (Mbps) to many gigabits per second (Gbps). Because of its asynchronous nature, ATM is more efficient than synchronous technologies, such as time-division multiplexing (TDM).
With TDM, each user is assigned to a time slot, and no other station send in that time slot. If a station has much data to send, it can send only when its time slot comes up, even if all other time slots are empty. However, if a station has nothing to transmit when its time slot comes up, the time slot is sent empty and is wasted. Because ATM is asynchronous, time slots are available on demand with information identifying the source of the transmission contained in the header of each ATM cell.
ATM Cell Basic Format
ATM transfers information in fixed-size units called cells. Each cell consists of 53 octets, or bytes. The first 5 bytes contain cell-header information, and the remaining 48 contain the payload (user information). Small, fixed-length cells are well suited to transferring voice and video traffic because such traffic is intolerant of delays that result from having to wait for a large data packet to download, among other things. Figure illustrates the basic format of an ATM cell.
An ATM is a computerized telecommunications device that provides the financial transactions of a customer in a public space without the need for a human clerk.
Cash point or Bancomat in Europe and Russia
HISTORY & LOCATION
Invented by Scot John Shepherd-Barron on 27 June 1967
Installed in Barclays Bank of Enfield town
Mechanical cash dispenser by Luther George Simjian in 1939 at New York city
Storing of PIN on card by John Rose in 1965
Reg Varney used the first ATM in 1967
On and Off premise installations
Financial networks & Global use
Having a sign indicating name and networks called Topper
An usage of connecting ATM’s to interbank networks namely PLUS,Cirrus,Interac and LINK
Authorization of Financial transaction by communication network often through ISO 8583
Many banks charge ATM usage fees
ATM’s connect to transaction processor through dial-up modem by telephone or leased line
World wide ATM use is 1.5million as of august2007
Software & Hardware
A Wincor Nixdorf ATM running with Windows 2000
Platforms used in ATM include MS-DOS,PC-DOS etc..
Java,Linux,Unix can also be used
Through Linux finding some reception,MS-DOS was replaced by Linux
CAL protocols such as Diebold 911 or 912 are replace by new protocols as IFX
Financial institutions are interested in using CEN FXS or FXS which provide common API
ATM’s include CPU,chipcard,PIN pad,Touchscreen,vault
As related to security there are several dimensions
Security is focused on making ATM’s invulnerable to physical attack
Dye markers and Smoke canisters are the prevention methods for explosive techniques
Customer identity & integrity:
Taking counter measures to protect equipment from criminals
Device operation integrity:
ATM’s that are exposed to the outside must be vandal and weather resistant
Maintaining sensor alarms prevent tampering when they are not in use
Security guards watching over ATM’s that have been installed in a van
Maintaining emergency PINs, landscaping, cameras can prevent crimes
ATMs: Automated Teller Machines
What is an ATM ??
An automated teller machine (ATM) is a computerized telecommunications device that provides the customers of a financial institution / bank with access to financial transactions in a public space without the need for a human clerk or bank teller round the clock (24 hrs a day).
History Of ATM
The ATM was invented by Scot John Shepherd-Barron.
The world's first ATM was installed in a branch of Barclays in the northern London borough of Enfield, Middlesex, in 1967.
A mechanical cash dispenser was developed and built by Luther George Simjian and installed in 1939 in New York City by the City Bank of New York
The first person to use the machine was Reg Varney of "On the Buses" fame, a British Television programme from the 1960s
The idea of a PIN stored on the card was developed by the British engineer John Rose in 1965.
the modern, networked ATM was invented in Dallas, Texas, by Don Wetzel in 1968
Notable historical models of ATMs include the IBM 3624 and 473x series, Diebold 10xx and TABS 9000 series, and NCR 5xxx series.
Functions of ATM
24-hour access to cash
View Account Balances & Mini-statements
Order a Cheque Book / Account Statement
Transfer Funds between accounts
Refill your Prepaid card
Pay your utility bills
Deposit cash or cheques
Change your PIN
Learn about other products
On most modern ATMs, the customer is identified by inserting a plastic ATM card with a magnetic stripe or a plastic smartcard with a chip, that contains a unique card number and some security information.
Security is provided by the customer entering a personal identification number (PIN).
Reg Varney using the first ATM in 1967
Structure of ATM
The card reader captures the account information stored on the magnetic stripe on the back of an ATM/debit or credit card. The host processor uses this information to route the transaction to the cardholder's bank.
The keypad lets the cardholder tell the bank what kind of transaction is required (cash withdrawal, balance inquiry, etc.) and for what amount. Also, the bank requires the cardholder's personal identification number (PIN) for verification. Federal law requires that the PIN block be sent to the host processor in encrypted form.
The display screen prompts the cardholder through each step of the transaction process. Leased-line machines commonly use a monochrome or color CRT (cathode ray tube) display. Dial-up machines commonly use a monochrome or color LCD.
The receipt printer provides the cardholder with a paper receipt of the transaction
The heart of an ATM is the safe and cash-dispensing mechanism. The entire bottom portion of most small ATMs is a safe that contains the cash.
Working Of ATM