Summary of ON24 streaming technologies.
HTTP-Based Live Streaming
HTTP-based Live streaming is unarguably the dominant form on video distribution on the web today. Initially spearheaded by on-demand streaming on sites like YouTube and Netflix, HTTP-based streaming solutions have now become the norm even for Live distribution with companies who have had a major influence on this market – including Microsoft, Apple, and Adobe. These technologies include HLS (HTTP Live Streaming).
In HTTP-based streaming like HLS, the player accesses a manifest, then fetches media segments based on the manifest indication of which speeds are currently available. Streams are encoded in multiple bit-rates. Multiple bit-rates support Adaptive Bit-rate (ABR) streaming – Which allows the player to step the bit-rate fetched up or down based on network conditions.
ON24 streams live events via HLS using 2500k and 300k video bit rates as its standard live ABR configuration. HLS (mobile) ABR rates are similar.
Content Distribution Networks and Peer to Peer Distribution
Content Distribution Networks, or CDN’s, are a means to store, or cache, content on remote servers that can be scaled independently and deployed in multiple geographic regions to amplify and optimize the ability to deliver to large audiences. In this deployment model, each viewer downloads the stream independently from the CDN.
With delivery within large enterprises, this poses a challenge, since hundreds or thousands of separate concurrently requested streams need to traverse the corporate firewall that is required for security reasons. In addition, every viewer has a dedicated connection to the CDN server, increasing WAN bandwidth and requiring a very large Internet pipe. Provisioning such high capacities for the firewall and internet link is very expensive, and typically not worthwhile. The solution for most enterprises is either more bandwidth or use of Peer-to-Peer distribution.
With Peer to Peer distribution, there is a locally installed "agent" – stream accesses go to this agent; it acquires and serves the stream or fragments. The software can fetch the fragments from other nearby copies of the agent, rather than fetching streams from outside the network. This architecture is termed Enterprise CDN (or eCDN), and does have all the flexibility of a software-based solution like flexibility, easy upgrades, and lower costs. And it limits bandwidth use to perhaps 2-5% of that required to serve separate CDN streams per user.
Enterprise CDNs and ON24
There are two main vendors in the eCDN space: Kollective and Hive Streaming, and the ON24 platform fully integrates with both.
Note: When lobby music / video is included in a Hive event, the lobby music / video is streamed using a CDN (i.e. not using Hive). Once the event is started, all content is streamed using Hive. Kollective does not support any Lobby Music or Video, custom or default.
Hive
Hive provides for HLS delivery. ON24 seamlessly integrates with Hive for the delivery of HLS streams. Clients or prospects who have Hive deployed have a collection of user workstations with Hive “agents” deployed. The integration between ON24 and Hive allows API calls that associate an ON24 stream with a Hive media object identifier.
ON24 pulls the stream through the Hive agent, leveraging the Hive PTP distribution service. The integration allows Hive Only configuration – where clients would prefer that users who fail Hive access got no stream, or Hive with CDN fail through. In the latter case, Hive incapable users (e.g., non-employees, or external users) fail through to the CDN without it being visible.
Kollective
Kollective provides for HLS delivery capability was enabled with Kollective Agent version 10.6.
From an ON24 perspective, clients or prospects who have Kollective deployed have a collection of user workstations with Kollective “agents” deployed. Integrating ON24 and Kollective allows API calls to associate an ON24 stream with a Kollective media object identifier (“moid”). The ON24 console pulls the stream through the Kollective agent, leveraging the Kollective PTP distribution service. The integration allows Kollective Only configuration – when preferred, that users who fail Kollective access got no stream, or Kollective with CDN fail through. In the latter case, Kollective incapable users fail through to the CDN without it being visible.
The failover logic for Kollective HLS is:
If Kollective Only mode is set:
-
If <10.6 K agent is found, console plays RTMP Kollective Stream
-
If 10.6 or+ is found, HLS Kollective is attempted, with fail through to K RTMP stream if HLS stream fails.
- If <10.6 Agent detected, Play K RTMP, Fail to CDN RTMP
- If 10.6 or + is detected, Play K HLS, fail to HLS CDN, then fail to K RTMP, then fail to CDN RTMP
Integration Information
Kollective eCDN integration requires three data elements, supplied by Kollective or by the client:
- Service Endpoint – the URL for the API server to be used
- Service Token – base64 encoded credentials for authentication to the API server
- User Name – credentials to be used for API calls These data elements are provided by Kollective on the direction of their client to allow ON24 access
Technical Notes
Adaptive Bitrate: Adaptive Bitrate is seen as one of the benefits of HTTP-based stream delivery. Multiple streams are generated at different bandwidths, and the player switches between them based on the available bandwidth. In the case of internal delivery where an eCDN is used, ABR may not be desirable. Multiple bitrates mean more network traffic across the firewall, less efficient eCDN distribution, and potentially more unpredictability in traffic and network congestion. So with the ON24 implementation of eCDN, ABR may optionally be deployed.
Mobile Support: ON24 mobile streams are not PTP-enabled. In general, the number of mobile devices participating is relatively small, and access is generally through visitor/guest wifi, so PTP distribution does not make sense.
Encoding and Distribution Summary
Encoding Approaches
There are many ways a company may wish to source their video content. Companies with in-‐house studios or production facilities tend to prefer Encoding on Site. Those without such facilities may prefer video conferencing (H.323) transmission (e.g. Cisco Video Conferencing Units), Skype for Business, or even a packaged Encode on Site approach; and those with less formal objectives may prefer webcam or phone-based audio. ON24 supports each of these options.
Supported Delivery Protocols
- The advent of HTTP-‐based streaming adds rich options for streaming. ON24 supports:
- H.264 streams (with MP3 or AAC based audio) delivered via HTTP Live Streaming (to iOS and Android devices) delivered via HTTPS
- Flash streams via RTMP-‐based protocols (RTMP, RTMP/T, RTMP/E, RTMP/S), (deprecated).
Supported Distribution Channels
ON24 delivers over a rich collection of standard and custom-engineered distribution channels for both internal and external delivery.
- eCDNs/PTP
- Hive (HLS)
- Kollective (HLS with 10.6+ Agents)
- CDNs (HLS)
- Limelight
- Edgecast
- Akamai
- Level3
Comments
0 comments
Please sign in to leave a comment.