Summary

The increased use of audio-visual traffic on the Internet forces cable operators to invest in additional facilities each year. Most of the audio-visual traffic is unicast, which, unlike multicast, consumes much bandwidth, but is easy to use, and compatible with consumer devices such as smartphones and tablets.

Since some of unicast connections carry linear programming such as news and sports, the traffic on the delivery network can be significantly reduced if such linear programs are transmitted as a multicast.

Recommendation ITU-T J.484 defines the requirements of an Internet protocol (IP) delivery technology which makes use of multicast to reduce audio-visual traffic in the cable delivery network but uses hypertext transfer protocol (HTTP) based unicast inside the home network, thereby making it compatible with consumer devices such as smartphones.