What is the communication process from an ATM to our company? An ATM is a computer terminal like a normal desktop computer. It only differs in appearance, number of inputs/outputs devices, and the types of tasks it can accomplish. An ATM has an input system that the customer uses to pass commands to the ATM and an output system for communicating to the user. The customer inserts his/her card to begin the transaction. The ATM performs several tasks. These tasks are carried out by programs that have been loaded in the ATMs. Such example is authenticating the user of the ATM card. Here the program types an instruction for the user to enter the PIN (Personal Identification Number), after the user types the PIN, it reads and encrypts it for security purposes, transmits it via a particular port through a network to our server. The server then receives the information (The PIN, user account number and other details encrypted) and transmits it to our computer that has user authentication and other data processing programs. The program decrypts the data and performs a user identification process. It then sends a response to the ATM via our intranet to the server, from the server through the external network to the ATM (Bowen, 2008, para.2).
Our company has agreed on a deal where our clients and the clients of Unbelievable Wisdom Credit Union (UWCU) will be sharing the ATMs of both companies. Two problems arise here. One of them is networking one company’s ATMs to the other Companies Computers. The second is that the computer applications of the two companies use different port numbers. The issue of networking can be solved in two ways. An extra connection line (Leased line or Dial-up connection) can be made from ATMs of one company to the server (and thus the intranet) of the other company. The second solution is to establish a network between the intranets of the two companies. This solution would also require making changing configuration settings of firewalls (packet filtering, Bastion LAN, proxy firewall etc) at both companies to permit communication to occur between computers of both companies. The second problem of port numbers is the major one. The changes that need to be made will not affect the way data is transmitted from the ATMs to our server. This is because no data processing is done along with the network, only packet switching is done along with the network and this does not affect the data or applications that will process the data. The port number used depends on data embedded in the ATM card. Networked programs communicate through sockets. Java.sun.com, the certified website of Sun considers a socket as a “single endpoint of a duo-way communication connection in two programs running on the network. A socket is bound to a port number so that the TCP layer can identify the application that data is destined to be sent” (Sun, n.d, para.4). The application programs at the ATMS and the Host computers will be affected. Since the choice of interconnecting our intranets is best (to problem one)’ the best way to solve the port problem is as follows. The programs in both types of ATMs should be modified to detect the type of card and then transmit the data using the cards’ associated port. The server or an application program hosted on a client computer at each company would then check the Port number. Based on the port number (3211 or 4744) the data would be sent to our computers or UWCU computers that company’s intranet, external network and the other company’s intranet(Sun, n.d, para. 1-5).
Reference list
Bowen, J. How ATMs work (1999). Web.
Sun. The JavaTM (n.d) Tutorials: What Is a Socket? Web.