ABR Quality Monitoring: State of the Art

Bibliographic Reference(s)

• ISO.23009-1.2014 — ISO/IEC 23009-1:2014, Information Technology-Dynamic Adaptive Streaming Over HTTP (DASH)-Part 1: Media Presentation Description and Segment Formats. EXTERNAL
• American National Standards Insitute/Society for Cable Television Engineers (ANSI/SCTE), ANSI/SCTE 168-6 2017, “Recommended Practice for Monitoring Multimedia Distribution Quality.” EXTERNAL
• J. Welch, “The Power and Challenges of Adaptive Streaming,” presented at the SCTE Cable-Tec Expo 2010, New Orleans, LA, Oct. 2010. EXTERNAL
• J. Welch, “Tuning, Configuring, and Monitoring Your Next ABR Video Encoder,” presented at the 2017 NAB Show, Las Vegas, NV, Apr. 2017. EXTERNAL
• J. Welch, “Simplifying Video Delivery Management,” presented at the SCTE Cable-Tec Expo 2011, Atlanta, GA, Nov. 2011. ■■ During a major sports package launch, it was determined through passive intra-CDN monitoring that all end-user traffic was being supplied from a single cache node due to a DNS issue. Rather than the intended conf ig uration of distr ibuting client requests to different cache nodes, all requests were routed to a single cache which, in turn, resulted in the origin server requests originating from only one cache. This resulted in poor performance for many end clients due to cache server oversubscription. ■■ During a sports package launch event, postedge cache passive monitoring showed that a game console client was only buffering one segment at a time. This led to frequent buffer underflows causing frequent rebuffering events and playback stalls impacting the playback experience quality. ■■ Intra-CDN passive monitoring led to the discovery that a server misconfiguration was erroneously set to time out and delete content causing caching to repeatedly fail and resulting in excessive origin server requests. Service rapidly became unusable. ■■ A CDN vendor reported to a customer that issues were caused by excessively long response time from the customer’s origin server. Intra-CDN monitoring proved this was not the case and pointed instead to CDN issues. ■■ A CDN vendor was not accurately logging HTTP response failures. Independent active synthetic client testing identified the HTTP response codes enabling rapid troubleshooting of the issue. ■■ Active synthetic client testing highlighted a “stalled” manifest condition causing content to loop on client players. ■■ Post-CDN synthetic client monitoring raised a high volume of VeriStream alarms indicating end-user clients may be having buffering issues. The early warning allowed for on-the-fly CDN tuning to proactively eliminate the delays and prevent end-user experience degradation. ■■ Intra-CDN passive monitoring identified a load balancer with performance issues under load. Early warning allowed the problem to be fixed before customers were impacted. All of these issues were rapidly identified by having sufficient realtime measurement data available and in a form that enabled system managers to pinpoint issues. Many incidents enabled managers to take action quickly before incidents escalated. In other cases, the measurement data enabled targeted corrective action after the event by providing data that likely would not have been available without realtime monitoring. Without definitive data about the incident, the providers are left to trial and error approaches that may require the occurrence of many incidents before the correct actions are identified. EXTERNAL
• Streaming Video Alliance’s QOE Industry Guidelines, “Key Network Delivery Metrics,” May 2016. EXTERNAL
• D. Jackson and J. Welch, “Zen and the Art of Media in Motion: The Many Aspects of Quality in the Media Supply Chain,” presented at the SMPTE 2017 Annual Technical Conference & Exhibition, Hollywood, CA, Oct. 2017. EXTERNAL
• J. Welch, “Active Monitoring Agents for Adaptive Bit Rate (ABR) Deployments,” presented at the 2015 NAB Show, Las Vegas, NV, Apr. 2015. EXTERNAL
• B. Stevenson, “Designing an Early Warning Monitoring System for Mass-Market Video Events,” presented at the 2018 NAB Show, Las Vegas, NV, Apr. 2018. EXTERNAL