Many corporations require combined voice, video and Internet access with a two-way Internet bandwidth of at least 100 Mbps. This is a forward-looking composite requirement that recognizes that a typical corporation with 250+ employees will be watching videos, talking on the telephone, and accessing the Internet all at the same uiuc self service.
About 300 million people in the world are telecommuting to work today. Better, faster, and cheaper communication infrastructure would mean a phenomenal increase in productivity and a better quality of life. Knowing the impact of Internet on mankind and despite hundreds of terabyte Internet bandwidth capacity across the world, what is stopping us from using bandwidth to its full extent? Why are we still talking of speed in terms of kilobits when hundreds of terabyte Internet capacities have already been laid and tested?
There exists a vast international bandwidth capacity across all continents and countries connecting their various cities and towns and terminating at various places that are called Point of Presence (PoP). More than a billion Internet users exist throughout the world. The challenge consists of connecting these users to the nearest POP. The connectivity between various client sites and POPs, called the last mile connectivity, is the bottleneck.
Internet Service Providers (ISPs) built the long haul and backbone networks spending billions over the past five years. ISPs spent to this extent to increase the broadband capacity by 250 times in long haul; yet, the capacity in the metro area increased only 16 fold. Over this period, the last mile access has remained the same, with the result that data moves very slowly in the last mile. Upgrading to higher bandwidths is either not possible or the cost is extremely prohibitive. The growth of Internet seems to have reached a dead end, with possible adverse effects on the quality and quantity of the Internet bandwidth that is available for the growing needs of enterprises and consumers.Compounding this is the technical limitations of Transmission Control Protocol / Internet Protocol (TCP/IP).
The Internet works on a protocol called the TCP/IP. TCP/IP performs well over short-distance Local Area Network (LAN) environments but poorly over Wide Area Networks (WANs) because it was not designed for it.
TCP as a transport layer has several limitations that cause many applications to perform poorly, especially over distance. These include: window size limitations for transmission of data, slow start of data transmission, inefficient error recovery mechanisms, packet loss, and disruption of transmission of data. The net result of issues is poor bandwidth utilization. The typical bandwidth utilization for large data transfers over long-haul networks is usually less than 30 percent, and more often less than 10 percent. Even if a chance of upgrading the last miles even at very high costs exists, the effective increase would be only 10 percent of the upgraded bandwidth. Hence, upgrading networks is a very expensive proposition.
A new technology called the ‘Application Acceleration’ has emerged, which accelerates the Internet applications over WANs using the same Internet infrastructure, circumventing to some extent the problems caused due to lack of bandwidth.
Application accelerators, as the name suggests, are appliances that accelerate applications by reengineering the way data, video, and voice is sent/transmitted over networks. Application acceleration addresses non-bandwidth congestion problems caused by TCP and application-layer protocols, thereby, significantly reducing the size of the data being sent along with the number of packets it takes to complete a transaction, and performs other actions to speed up the entire process.
Application accelerators can also monitor the traffic and help with security. Some appliances mitigate performance issues by simply caching the data and/or compressing the data before transfer. Others have the ability to mitigate several TCP issues because of their superior architecture.
These appliances have the ability to mitigate latency issues, compress the data, and shield the application from network disruptions. Further, these new appliances are transparent to operations and provide the same transparency to the IP application as TCP/IP application accelerators have the following features using Layer 4-7 Switching.