Open Casting
Working Group:
In Collaboration With:
Project Status:
Working
The project is actively being worked on.
Start:
January 2, 2024
Target End:
December 31, 2024
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Problem Statement
Determine how an IP multicast video service infrastructure (such as MABR – for Multicast Adaptive Bit-Rate) can be exposed, open and shared across the Open Caching API. The telecom operator owns and operates the multicast video distribution infrastructure. With Open Caching it should be able to open and to expose this to any content provider (and CDN provider) in a conventional/standardized way.
Project Description
A multicast video infrastructure (such as Multicast ABR) enables the delivery of video content over IP multicast in a way such that both the end-user terminal and the content server may be unaware of the multicast delivery. Open Casting can be used in the content delivery network using multicast instead of unicast for delivery, presenting several benefits for operators, including reducing bandwidth and request loads throughout the network, and enabling in some cases the reuse of network setup for legacy IP-based television services over multicast (IPTV).
Although a multicast video service such as MABR can be deployed over a one way only delivery infrastructure, it is fundamentally a hybrid technology relying on multicast, for sure, but potentially also on unicast allowing fast start, segment repair, seamless unicast/multicast switch over.
On the standardization front, video over IP multicast has been popularized by the IPTV service relying mostly on broadband specifications (e.g. Broadband Forum). The trend is to adapt the IPTV infrastructure with MABR (Multicast Adaptive Bit Rate).
The DVB-MABR specification was released in March 2020 as the DVB BlueBook A176 that became an ETSI specification TS 103 769 V1.1.1 in November 2020. It came out after a first specifications set related to multicast ABR published by CableLabs in 2015 along with a technical report. Although both standards look similar, the DVB-MABR specification relies on the latest evolution of the ABR streaming technology and leverages years of deployments and experiments introducing several improvements. For example, DVB-MABR defines a new core component for request routing, extends the overall configuration possibilities by adding a lot of flexibility in deployments, and provides a comprehensive reporting framework. In addition, DVB MABR specifies new multicast transport protocols beyond NORM solely used in the CableLabs specification. Finally it also adds security features, such as authentication and tampering protection.
Beside standardization, there exist proprietary implementations of multicast video streaming including those that share the same MABR principles of their standardized counterparts.
Since the white paper published by the SVTA in 2019, we have seen several press releases about content providers and ISPs adopting Multicast ABR. After envisaging and deploying OTT streaming over unicast exclusively, there seems to be an interest in reducing the bandwidth and infrastructure footprint in adopting a more balanced approach with multicast video streaming.
Open Caching targeted primarily the CDN (as a service) providers allowing them to extend their CDN footprint through interacting with a downstream/ISP CDN across the Open Caching API.
With Open Casting, we target both content providers and CDNs, allowing them to benefit from a multicast video infrastructure that is hosted in the telecom operator network domain.
Project Type
Document
Project Leads
Advisors
There are no SMEs associated with this project.
Goals and Objectives
To write a specification document related to Open Casting, including the following:
- Use cases definition (with a focus on video streaming)
- List the requirements for having a multicast video service exposed across the Open Caching API
- Specify the architecture and modes of operation associated with supporting those use cases (live streaming being one of them)
- Depict the impact on the existing Open Caching interface APIs
- Have this specification independent from any multicast video streaming (e.g. MABR) standardized solutions and proprietary solutions
- Update the Open Caching implementation guideline with a couple of scenarios considering the new specification
- Build a testbed proving the feasibility of the new specification
Project Scope
The project targets a specification document allowing, on one hand any ISP that hosts a multicast video infrastructure to expose the service through the Open Caching API and on the other hand any content provider (or upstream CDN providers ) to beneficiate and operate the downstream multicast video service.
The multicast video service can be completely hidden and abstracted by the Open Caching API. However this does not preclude working on how to map the multicast video infrastructure and service with the Open caching API.
There is also an interest from both parties, i.e. the downstream ISP and the upstream content provider, to intentionally expose and operate respectively the multicast video service across the Open Caching API. A minimum set of features have already been provisioned in Open Caching allowing an ISP to announce multicast video support and a content provider to request and configure the video streaming delegation through the multicast video infrastructure. However this is very basic and a lot more features may be exposed across the Open Caching interface covering security, request routing, unicast/multicast synchronization, flow control, logging, etc.
Contributors
The following members have contributed to this project. Click on their name to visit their profile. If they have not published their profile, the link will redirect to their LinkedIn profile.
Additional References
Presentations
The following presentations delivered during Open Caching working group sessions may provide additional information about this project.