Video: Layer 4 in the CDN

Caching is a critical element of the streaming video delivery infrastructure, but with the proliferation of streaming services, managing caching is complex and problematic. Open Caching is an initiative by the Streaming Video Alliance to bring this under control allowing ISPs and service providers a standard way to operate.

By caching objects as close to the viewer as possible, you can reduce round-trip times which helps reduce latency and can improve playback but, more importantly, moving the point at which content is distributed closer to the customer allows you to reduce your bandwidth costs, and create a more efficient delivery chain.

This video sees Disney Streaming Services, ViaSat and Stackpath discussing Open Caching with Jason Thibeault, Executive Director of the Streaming Video Alliance. Eric Klein from Disney explains that one driver for Open Caching is from content producers which find it hard to scale, to deliver content in a consistent manner across many different networks. Standardising the interfaces will help remove this barrier of scale. Alongside a drive from content producers, are the needs of the network operators who are interested in moving caching on to their network which reduces the back and forth traffic and can help cope with peaks.

Dan Newman from Viasat builds on these points looking at the edge storage project. This is a project to move caching to the edge of the networks which is an extension of the original open caching concept. The idea stretches to putting caching directly into the home. One use of this, he explains, can be used to cache UHD content which otherwise would be too big to be downloaded down lower bandwidth links.

Josh Chesarek from StackPath says that their interest in being involved in the Open Caching initiative is to get consistency and interoperability between CDNs. The Open Caching group is looking at creating these standard APIs for capacity, configuration etc. Also, Eric underlines the interest in interoperability by the close work they are doing with the IETF to find better standards on which to base their work.

Looking at the test results, the average bitrate increases by 10% when using open caching, but also a 20-40% improvement in connection use rebuffer ratio which shows viewers are seeing an improved experience. Viasat have used multicast ABR plus open caching. This shows there’s certainly promise behind the work that’s ongoing. The panel finishes by looking towards what’s next in terms of the project and CDN optimisation.

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Speakers

Eric Klein Eric Klein
Director, CDN Technology,
Disney+
Dan Newman Dan Newman
Product Manager,
Viasat
Josh Chesarek Josh Chesarek
VP, Sales Engineering & Support
Stackpath.com
Jason Thibeault Jason Thibeault
Executive Director, Streaming Video Alliance

Video: CMAF And The Future Of OTT

Why is CMAF still ‘the future’ of OTT? Published in 2018, CMAF’s been around for a while now so what are the challenges and hurdles holding up implementation? Are there reasons not to use it at all? CMAF is a way of encoding and packaging media which then can be sent using MPEG DASH and HLS, the latter being the path Disney+ has chosen, for instance.

This panel from Streaming Media West Connect, moderated by Jan Ozer, discusses CMAF use within Akami, Netflix, Disney+, and Hulu. Peter Chave from Akamai starts off making the point that CMAF is important to CDNs because if companies are able to use just one CMAF file as the source for different delivery formats, this reduces storage costs for consumers and makes each individual file more popular thus increasing the chance of having a file available in the CDN (particularly at the edge) and reducing cache misses. They’ve had to do some work to ensure that CMAF is carried throughout the CDN efficiently and ensuring the manifests are correctly checked.

Disney+, explains Bill Zurat, is 100% HLS CMAF. Benefiting from the long experience of the Disney Streaming Services teams (formerly BAMTECH), but also from setting up a new service, Disney were able to bring in CMAF from the start. There are issues ensuring end-device support, but as part of the launch, a number were sunsetted which didn’t have the requirements necessary to support either the protocol or the DRM needed.

Hulu is an aggregator so they have strong motivation to normalise inputs, we hear from Hulu’s Nick Brookins. But they also originate programming along with live streaming so CMAF has an important to play on the way in and the way out. Hulu dynamically regenerates their manifests so can iterate as they roll out easily. They are currently part the way through the rollout and will achieve full CMAF compatibility within the next 18 months.

The conversation turns to DRM. CMAF supports two methods of DRM known as CTR (adopted by Apple) and CBC (also known as CBCS) which has been adopted by others. AV1 supports both, but the recommendation has been to use CBC which appears have been universally followed to date explains Netflix’s Cyril Concolato. Netflix have been using AV1 since it was finalised and are aiming to have most titles transitioned by 2021 to CMAF.

Peter comments from Akamai’s position that they see a number of customers who, like Disney+ and Peacock, have been able to enter the market recently and move straight into CMAF, but there is a whole continuum of companies who are restricted by their workflows and viewer’s devices in moving to CMAF.

Low latency streaming is one topic which invigorates minds and debates for many in the industry. Netflix, being purely video on demand, they are not interested in low-latency streaming. However, Hulu is as is Disney Streaming Services, but Bill cautions us on rushing to the bottom in terms of latency. Quality of experience is improved with extra latency both in terms of reduced rebuffering and, in some cases, picture quality. Much of Disney Streaming Services’ output needs to match cable, rather than meeting over-the-air latencies or less.

The panel session finishes with a quick-fire round of questions from Jan and the audience covering codec strategy, whether their workflows have changed to incorporate CMAF, just-in-time vs static packaging, and what customers get out of CMAF.

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Speakers

Cyril Concolato Cyril Concolato
Senior Software Engineer,
Netflix
Peter Chave Peter Chave
Principal Architect,
Akamai
Nick Brookins Nick Brookins
VP, Platform Services Group,
Hulu
Bill Zurat Bill Zurat
VP, Core Technology
Disney Streaming Services
Jan Ozer Moderator: Jan Ozer
Contributing Editor, Streaming Media
Owner, StreamingLearningCenter.com

Video: Everyone is Streaming; Can the Infrastructure Handle it?

How well is the internet infrastructure dealing with the increase in streaming during the Covid-19 pandemic? What have we learnt in terms of delivering services and have we seen any changes in the way services are consumed? This video brings together carriers, vendors and service providers to answer these questions and give a wider picture.

The video starts off by getting different perspectives on how the pandemic has affected their business sharing key data points. Jeff Budney from Verizon says that carriers have had a ‘whirlwind’ few weeks. Conviva’s José Jesus says that while they are only seeing 3% more devices, there was a 37% increase in hours of video consumed. Peaks due to live sports have done but primetime is now spread and more stable, a point which was made by both Jeff Gilbert from Qwilt as well as José.

“We’ve seen a whole year’s worth of traffic growth…it’s really been incredible” — Jeff Budney, Verizon

So while it’s clear that growth has happened, but the conversation turns to whether this has caused problems. We hear views about how some countries did see reductions in quality of experience and some with none. This experience is showing where bottlenecks are, whether they are part of the ISP infrastructure or in individual players/services which haven’t been well optimised. Indeed, explains Jason Thibeault, Executive Director of the Streaming Video Alliance, the situation seems to be shining a light on the operational resilience, rather than technical capacity of ISPs.

Thierry Fautier from Harmonic emphasises the benefits of content-aware encoding whereby services could reduce bandwidth by “30 to 40 percent” before talking about codec choice. AVC (A.K.A. H.264) accounts for 90%+ of all HD traffic. Thierry contents that by switching to both HEVC and content-aware encoding services could reduce their bandwidth by up to a factor of four.

Open Caching is a working group creating specifications to standardise an interface to allow ISPs to pull information into a local cache from service providers. This moving of content to the edge is one way that we can help avoid bottlenecks by locating content as close to viewers as possible.

The elephant in the room is that Netflix reduced quality/bitrate in order to help some areas cope. Verizon’s Jeff Budney points out that this is contra to the industry’s approach to deployment where they have assumed there is always the capacity to provide the needed scale. If that’s true, how can one tweet from a European Commissioner have had such an impact? The follow on point is that if YouTube and Netflix are now sending 25% less data, as reports suggest, ABR simply means that other providers’ players will take up the slack, as is the intent-free way ABR works. If the rest of the industry benefits from the big providers ‘dialling back’ is this an effective measure and is it fair?

The talk concludes hitting topics on ABR Multicast, having more intelligent ways to manage large-scale capacity issues, more on Open Caching and deliver protocols.

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Speakers

Thierry Fautier Thierry Fautier
VP Video Strategy, Harmonic Inc.
President-Chair, Ultra HD Forum
Eric Klein Eric Klein
Director, Content Distribution – Disney+/ESPN+, Disney Streaming Services
Co-Chair, Open Cache Working Group, Streaming Video Alliance
José Jesus José Jesus
Senior Product Manager,
Conviva
Jeffrey Budney Jeff Budney
Manager,
Verizon
Jeffrey Gilbert Jeffrey Gilbert
VP strategy and Business Development, CP,
Qwilt
Jason Thibeault Jason Thibeault
Executive Director,
Streaming Video Alliance

Video: Video Caching Best Practices

Caching is a critical element of the streaming video delivery infrastructure. By storing objects as close to the viewer as possible, you can reduce round-trip times, cut bandwidth costs, and create a more efficient delivery chain.

This video brings together Disney, Qwilt and Verizon to understand their best-practices and look at the new Open Caching Network (OCN) working group from the Streaming Video Alliance. This recorded webinar is a discussion on the different aspects of caching and the way the the OCN addresses this.

The talk starts simply by answering “What is a caching server and how does it work?” which helps everyone get on to the same page whilst listening to the answers to “What are some of the data points to collect from the cache?” hearing ‘cache:hit-ratio’, ‘latency’, ‘cache misses’, ‘data coming from the CDN vs the origin server’ as some of the answers.

This video continues by exploring how caching nodes are built, optimising different caching solutions, connecting a cache to the Open Caching Network, and how bettering cache performance and interoperability can improve your overall viewer experience.

The Live Streaming Working Group is mentioned covered as they are working out the parameters such as ‘needed memory’ for live streaming servers and moves quickly into discussing some tricks-of-the-trade, which often lead to a better cache.

There are lots of best practices which can be shared and the an open caching network one great way to do this. The aim is to create some interoperability between companies, allowing small-scale start-up CDNs to talk to larger CDNs. A way for a streaming company to understand that it can interact with ‘any’ CDN. As ever, the idea comes down to ‘interoperability’. Have a listen and judge for yourself!

Watch now!
Speakers

Eric Klein Eric Klein
Director, Content Distribution – Disney+/ESPN+, Disney Streaming Services
Co-Chair, Open Cache Working Group, Streaming Video Alliance
Yoav Gressel Yoav Gressel
Vice President of R&D,
Qwilt
Sanjay Mishra Sanjay Mishra
Director, Technology
Verizon
Jason Thibeault Jason Thibeault
Executive Director,
Streaming Media Alliance