VoD has been an epically wasteful distribution medium. Still, Multicast has epically failed too; being thoroughly unsuccessful in gaining adoption.
As a technology, Real time Multicasting is not uncommon for live video distribution within private virtual networks. Despite the considerable reductions in capital and operational expenditures that Multicast allows, it has not lived up to its potential. There are several reasons for this.
- Interdomain Multicast has been poorly supported by all Tiers of ISP networks. The approaching ubiquity of IPv6, in tandem with adjustments to industry-wide best practices changes this. The fruits of Interdomain Multicast are now easily within reach. The topic of Internet evolution is discussed elsewhere on this site.
- Local ISPs never viewed Multicast as an opportunity within an IPv4 landscape. This is in part due to the obstacles presented by residential NAT routers. As I describe later, the availability of IPv6 and its running partner, 5G New Radio, render this obstacle moot.
- For VoD, Multicast fails to provide the operational immediacy required of Video-on-Demand. Multicast is an unsatisfactory means for Video-on-Demand as the subscriber often wishes to pause, Fast-Forward, Rewind and re-start the content. This critical limitation can be overcome with approaches described on other pages of this site.
AT&T’s unsuccessful “Triple-Play” Cable replacement service; U-verse, admirably used multicast for Live TV delivery. AT&T sidestepped the interdomain challenges by using a private network delivery system. U-verse avoided operational immediacy matters, ceding to wasteful Unicast for VoD, and time-shifted catchup content.
Hybrid VoD 