CDN Video Delivery in ScreenLight

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We all hate it when videos take a long time to load and when playback stutters. There are plenty of stats that show engagement and viewing time on consumer video sites decreases as buffering increases.

Things are a bit different with a video collaboration platform. Your stakeholders may not be able to go elsewhere if your videos get stuck buffering. However, their satisfaction with the review process and your brand will be impacted if videos do not play properly. In fact, one of the key aspects of a video collaboration application is reliable and secure video delivery.

Since delivering a great video review experience is at the core of our mission at ScreenLight, we have decided to use Amazon's CloudFront content delivery network (CDN) to accelerate video delivery for our customers. Serving your videos from Amazon's global network of edge locations means that viewers will experience fast, low latency video playback with minimal buffering, regardless of where they happen to be or how many people are watching at once.

How ScreenLight's CDN accelerated video delivery works

As a general principle, when delivering content on the Internet, the closer it is to the end user, the faster it can be delivered. There are fewer router hops and a smaller chance that a video stream will be disrupted during its journey.

By using a CDN, we can ensure that videos are delivered from locations that are as close as possible to your collaborators. With over 30 different edge locations at our viewers disposal, we can ensure they have the best possible viewing experience in all corners of the world.

CloudFront locations

When you upload a video into ScreenLight, we store the master version in our Amazon S3 storage location. If you aren't familiar with it, S3 is a cloud storage service that uses the same reliable infrastructure that Amazon uses to power its ecommerce operations. S3 provides us with unlimited amount of storage that is secure, fast, and continuously backed up. Assets are redundantly stored on multiple devices, across multiple data centers. Two different facilities could fail concurrently and the assets would still be safe. The storage service is designed to provide 99.999999999% durability and 99.99% availability of objects that are stored. Needless to say videos in the master location are safe.

When someone starts to play a video, the request is automatically routed to the edge location nearest the viewer that offers the lowest latency. CloudFront then automatically checks to see if there is a copy of the video in that location. If there is a copy, then the video will be immediately played back from there.

If there is not a local copy, then the video is instantly delivered from our master storage location to the appropriate location via Amazon's managed network. The video is then played back from the edge location. It will then be stored (cached) at that location for viewing by other authenticated ScreenLight users.

All of this is transparent to the user and is totally seamless.

Advantages of using a CDN for ScreenLight

Aside from faster data transfer rates and lower latency, we believe that using CloudFront offers several other advantages over serving videos from a single location or a small number of locations.

  • Scalability. We have virtually limitless capacity at our disposal. We can handle spikes in usage and huge numbers of concurrent viewers on our platform without having to worry about the streaming servers being congested or not having enough bandwidth to support viewers at that location. As our user base grows, you don't have to worry about being squeezed for capacity by the viewing demands of other users.

  • Reliability. If the edge server nearest the viewer is not functioning properly or is experiencing high latency, then another location will automatically be used for playback.

  • Global presence. Creative review takes place on the go and around the world. If an exec is on a working vacation in Australia, it's better to serve them video directly from there rather than from a traditional production hub like L.A., New York, or London.

We also use the CDN to deliver our website and parts of the application that benefit from its acceleration.

Securing assets in CloudFront

With all these moving parts, it's important to talk about how we ensure that your videos are secured.

All communication channels that we use are encrypted using either HTTPS or RTMPE. This includes traffic between your browser and our servers, as well as, between S3, CloudFront, and our encoding service.

Files cannot be accessed by viewers directly from S3. Files are only accessible via a signed CloudFront URL that is generated automatically by ScreenLight when the video player loads. The signed URLs are time based tokens that are only valid for a limited period of time. Once that time window has expired, the access token contained in the link will no longer work.

Outside of CloudFront, strict security measures are in place. Our servers are located in a highly secure hosting facility behind an enterprise level firewall. We regularly update our software infrastructure, use redundant systems, and regularly perform system backups.

The bottom line

Your videos are backed up in multiple locations, they are securely protected against unauthorized viewing, and they are ready to be quickly delivered to collaborators in far flung corners of the world on whatever device is convenient.

If you don't already have a ScreenLight account, get started now with a free 30-day trial.