Carrier Grade Voice Over IP (original) (raw)

Impact of VoIP and QoS on Open and Distance Learning

Turkish Online Journal of Distance Education-TOJDE July 2006 ISSN 1302-6488 Volume: 7 Number: 3 Article: 2, 2006

Social changes always follow technological changes; indeed each new invention brings about advances in our lifestyle. Not long ago letter writing was the only means of keeping in touch with relatives and friends who did not live nearby. With Alexander Graham Bell’s invention of the telephone, conversations could be held at a distance without the requirement of displaying oneself. Marconi’s wireless brought the news of the world into the living room of the nations. The communication technologies kept evolving till date. Radio, television, satellites, mobile phones and other developments followed. A few years ago, the telephone companies used to have a monopoly on voice communications. This situation is changing rapidly. Media and communications are expanding in directions never dreamed of several years ago. Co-axial cables are competing with telephone wires. Satellites and mobile technologies have made cellular phones proliferate everywhere. Desktop and portable computers equipped with the required interfaces and connected to the Internet, are becoming almost ubiquitous. Miniaturization and portability of electronic devices, as well as effective means of communicating are omnipresent in the digitalized world around us. IP has become an accepted standard for communications over data networks worldwide, and enterprises have successfully implemented it. Recently IP was used to transport voice between networks and devices. Voice can now be packetized and sent over a data network using VoIP technology (Handley, Schulzrinne, Schooler, & Rosenberg 2001). This revolutionary technology is now setting off a new trend i.e. the convergence of voice and data networks of new applications. Current landline telephone systems are based on circuit switching. A closer look at circuit switching will ensure the better understanding of VoIP and its packet switching nature.