Transitional mechanisms have been promoted to kindle interdomain multicast deployment. This notably includes Automatic Multicast Tunneling [AMT]. (Giuliano, 2014). AMT does not depend on a homogeneous end to end network be Multicast complaint. AMT has two components.
- An “AMT Relay”, envelops the Multicast content within a Unicast wrapper. It listens for discovery messages from AMT Gateways.
- An “AMT Gateway” initiates connections to one or more AMT Relays with discovery messages. It unwraps and redistributes the Multicast content.
In this manner, AMT facilitates Multicast packet distribution regardless of the undisciplined journey through the Internet. AMT is transitional. As Multicast use increases, Multicast Reluctant Administrative Domains [AD] will see economic motivations to enable Multicast.
AMT is here today and is very easily provisioned; arguably only “…one line of config” away. (Guiliano, 2019). Mr. Giuliano promotes a broad, egalitarian use of Multicast. His view is that Multicast opens many new and beneficial use cases, many of which we cannot even imagine. AMT is a steppingstone to greater adoption of a fully realized Interdomain Multicast.
An AMT Relay device has been deployed by a High School student. This implementation is instrumental in understanding the tangible accessibility of interdomain Multicast, despite Administrative Domain [AD] non-compliance.
(Zhang, 2017)
There is activity within the Internet Engineering Task Force [IETF] to formalize Best Current Practices [BCP] to deprecate the burdensome Any Source Multicast [ASM] for Interdomain use. Removing this heavy ASM impediment elevates Source Specific Multicasting [SSM]. SSM is a much easier lift. Importantly SSM represents the substantially greater use-case demand. This putative BCP recommendation is welcome, as this boost for SSM is beneficial for interdomain Hybrid SVoD.
A detailed, differential discussion of the AMT, BIER, IR, is worthy of additional attention. Regrettably, it is beyond the scope of this site, at least for now. Still, it’s relevant to the vitality of the Internet’s ongoing evolution. It specifically emphasizes the increasing embrace of Multicast for use cases that require greater economy. Undeniably, for the use case of SVoD.
No matter the waypoints along the internet evolution highway, it appears that
All roads lead to Rome.
Hybrid VoD 