Riding the Wave of Over The Top Video Streaming

Author: Jeff Webb

Content Delivery World 2016

My first public speaking event as Principal Streaming Architect came at the Content Delivery World conference in November 2016, where I presented on “Innovations in Live Streaming to Multiple Platforms”.

My impression of the conference was that it was very well attended and the whole day was extremely interesting. As you can see from its title, the conference has a strong focus on content delivery and is specially relevant for Broadcasters. The conference will return in 2017 and I look forward to attending.

What will you learn about Streaming at Scale?

The presentation addresses some of the most important questions for OTT providers that want to offer customers a premium experience;

  • The challenges of Live vs VOD?
  • How do we measure at scale?
  • How do we protect the customer experience?
  • How do we streaming to millions of customers?

One of the most noteworthy streaming challenges is Live sporting events such as Premier League Football. In the presentation, I describe the perfect storm of when Monday night football meets Game of Thrones.

I hope you find the presentation interesting and would be great to hear your comments.

Surfing the Video Tidal Wave

Scaling the Internet Infrastructure

Following on from my previous article about the oncoming tidal wave of online HTTP video and its impact on the Internet infrastructure, I reviewed a software solution that can help address this challenge.

One area that’s really important to understand is the direct correlation on video quality with content popularity, such as in the example of watching NFL football or Film and just as you get to a good point, your client starts buffering. As a consumer you have limited choices except to vote with your feet. As a content provider, you need to ensure your infrastructure meets both current peak and future demands, because when a flash crowd occurs the customer will blame you, rather than a CDN which is an essential part of the video delivery chain.

What are the requirements for a good video delivery  solution?

With any online HTTP video delivery solution, there are three essential things required to minimise video buffering.

  • Foremost it must be really fast and run at network wire rate to leverage  available server hardware.
  • Furthermore it must scale linearly so that we can increase performance with additional units.
  • Lastly it must be a software only solution deployable quickly in the cloud or on premise.

Introducing aiScaler

aiScaler is a commercial high performance HTTP caching proxy server. It achieves this as a memory based cache, using asynchronous polling technology within the Linux kernel, and avoids disk except when used for logs and configuration. This makes it ideal for live video streaming applications such as Apple’s HTTP Live streaming, MPEG Dash, Microsoft Smooth and Adobe Flash. To prove the marketing and validate the performance claims I prepared a set of live video benchmarks.

Recommended Architecture

My recommendation is to deploy aiScaler directly in front of your origin server platform, assuming that you’re already using a CDN to serve video content to customers, as this provides the best possible performance with added DDoS security protection. The high level architecture diagram below provides an example of this:

HLA Block diagram v3

Test Architecture

The aim of benchmark testing is for maximum throughput! without errors which can cause buffering, and so I removed CDN’s from the test scenario. The  following high level architecture diagram shows the test scenario for Mobile HLS video:

HLA Block Test diagram v3

aiScaler Test Results

The test scenario was made up of 2500 synthetic mobile HLS users based in North America and Europe. Notice that I am not using a CDN but directly testing aiScaler as the origin cache layer, with public cloud provider CenturyLink.

  • Total CenturyLink bandwidth consumed in 30mins was 973GB.
  • aiScaler reduces client buffering, resulting in a smoother customer video experience as shown in the average response graph below.
  • DNS Time To Live set to 1 min for fast failure detection.

HLS average bit rates

Average response time is a way of measuring how long the live video takes to download and should remain relatively flat, to avoid client buffering issues. The above graph shows that during the test a variance of around 1.5 seconds was achieved. The test results demonstrate that aiScaler scales linearly to support multiple CDN partners concurrently which provides greater resilience.

Test Results Explained

During the test results I captured a lot of data from clients and from aiScaler, the following results are the most interesting.

CTL Server Stats Combined

  • All data was captured at the end of a 30 minute test run.
  • Tests were run three times and results averaged.
  • All HTTP 200 OK’s between 120-140 requests per/sec.
  • No HTTP 403/404 errors were observed.
  • No HTTP 5xx errors were observed.
  • Each aiScaler instance achieved wire rate 1Gbps error free, which proves CenturyLink have a great cloud platform.
  • CPU usage on the aiScaler instances reached 50% with 2 CPU’s and 4GB memory.
  • We could have achieved faster throughput as the only bottleneck was the instance type limiting throughput to 1Gbps.
  • aiScaler has been independently tested in excess of 9Gbps on a single  Intel Xeon based server.

Test Conclusions

The results were encouraging as they proved  that Multi Gigabit throughput could be achieved across multiple CenturyLink data centers with no errors. Delivering online video over the top (OTT) content at scale is challenging, without a combination of excellent caching software and a good cloud platform. Security is also a major factor in any online service and I enabled aiScaler’s automatic DDoS protection during the testing period.


I was able to prove that by deploying aiScaler on a public cloud provider, wire rate performance of 1Gbps can be achieved on a single instance. If you require more than 1Gbps simply choose a different instance type or run multiple instances geographically dispersed for resilience.

Deploying aiScaler was a straightforward process and took less than 15 minutes. In testing it has proven to be very capable of serving online video at very high throughput and I’d recommend you seriously evaluate it for your business needs.


Future Tidal Wave of Mobile Video

Analysing Mobile Internet Video Trends 2015-2020

In this article I will examine the growing trends of Internet Mobile video and how consumer behaviour is rapidly adopting to a world of ‘always on content’ and discuss the impact on the underlying infrastructure. This is very important because we often assume that the Internet has infinite capacity and we can get frustrated by buffering, which wouldn’t happen with our satellite and terrestrial TV services.

This pattern also follows other observed trends in social media, namely twitter, facebook and instagram, which provide consumers and producers with a highly valuable return path on the content, that they’re engaged with. It’s also a double edged sword in what they can provide is both positive and negative feedback, this can affect the brand in unexpected ways.

The source of this analysis comes from Cisco’s excellent Visual Networking Index, updated annually, which tracks the growing usage patterns across mobile and non-mobile devices. The most recent mobile data is from February 2016 and makes a compelling argument for anyone involved in providing video services, to review your infrastructure hardware and software stacks, to meet this oncoming problem head on. As customers expectations have changed over the past few years, you’ll need be prepared to cope with a 50-100% traffic growth every year, for the next 4-5 years.

Population Growth

According to the US Census Bureau the world population will reach 8 Billion by 2025 and by 2020 there will be up to 5.5 billion mobile users across the globe. If we take a closer look at the individual regions, we can observe that the fastest growing location will be in Asia Pacific.


Cisco VNI 2015-20 Regional Growth

The data shows where the global opportunity lies, with up to 2.8 devices per capita in developed countries and over 1 elsewhere, which is provable in our modern connected world where your phone is the one device that you are never without.

Cisco VNI 2015-20 Per Capita Growth Continue reading

Introduction to CDN’s

In this training video, I answer the most common Content Delivery Network questions such as;

What are CDN’s?
How does a CDN work?
Who uses a CDN?
How does a CDN make my website faster?
Who are the CDN players?
How much does a CDN cost?

Jeff’s OTT Projects

My passion is for Over The Top video streaming and I believe it is the future of TV consumerism, with customers increasingly using their smart phones and tablets to view content. In my role as Solutions Architect at Sky, I’ve had the opportunity to work on all of the key video products and continue to develop them for growth and security, including;


Now TVVery successful commercial OTT service available on mobile, desktop, games consoles and smart TV’s.
Supports HLS and Smooth Streaming.


Sky GoSky’s commercial OTT service available on mobile, desktop and games consoles.
Supports HLS and Smooth Streaming.


Sky Sports Mobile TVThe first commercial HLS Streaming service in Europe, launched in 2009.
Supports HLS Streaming.


Sky NewsLive and On Demand editorial video content.
Supports HLS Streaming.

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