Multi Protocol Label Switching
Physical and Datalink
Applications that take advantage of multicast include video conferencing, corporate communications, distance learning, and distribution of software, stock quotes, and news. Today, these applications are run by two inefficient schemes - unicasting and broadcasting. In unicasting one copy of data is sent to each receiver. While unicasting is a simple mechanism for one-to-one communication, for one-to-many communication it brings the network to its knees due to its huge bandwidth demands. In broadcasting a single copy of data is sent to every user in the network solving the bandwidth problem. However it is not suitable if only few receivers requested the data. Multicasting solves these problems by streaming a single copy of data to the requesting receivers.