What is Video Caching?

Video caching temporarily stores frequently accessed videos, or segments of them, on a server close to where viewers sit on the network. The first viewer pulls the video from its source, and everyone after that is served the local copy, so the same file never crosses the WAN twice. Bandwidth optimization occurs because video no longer has to travel the entire length of the corporate network.

Caches are network services, usually software running on a virtual machine in a data center or branch site, and they stay available to every device that needs them, whether that is a desktop, a phone, or a tablet. Because caching is demand-driven, like peer-to-peer networking, it works for both live and on-demand video. However, unlike peer-to-peer, the constant availability of the cache makes it a better solution for the opportunistic caching of video on demand (VOD).

As you explore which eCDN is right for your enterprise, start by learning how each technology works. Then evaluate it based on your use cases and the configuration of your network.

Here are a few reasons why a video caching eCDN might be right for your enterprise:

• You stream both live broadcasts and video on demand (VOD)
• Portions or all of your network is not multicast-enabled
• You don’t want to manage and deploy client software
• Some users view your business videos using mobile devices like smartphones or tablets
• Security is paramount
• Remote workers access your enterprise videos using VPN

Video caching is by far one of the most versatile eCDN solutions on the market today. But once you evaluate the total landscape of your streaming environment, you might need a mix of eCDN solutions.

1. The first viewer requests the video. Software or hardware is placed in strategic locations around the network and close to concentrations of viewers. When the first viewer requests a video, the cache retrieves it from the origin video source, such as Microsoft Teams, Webex or Zoom.
2. The cache stores a local copy. The cache keeps that copy so it is ready for the next viewer at the same location.
3. Later requests are served locally. When other viewers in the same location request the same video, they receive it directly from the local cache, not the source. As a result, the video has less distance to travel, and fewer duplicate copies are transmitted across the corporate internet connections and WAN links.

Can I Just Use a Regular Caching Solution?

In theory, you could. But using a WAN accelerator is not the best way to distribute video. That’s because WAN accelerators were not made to cache all file types. They were designed to cache files from the internet, such as JPEG files and text files. These file types are pretty small in comparison to a video file.

Live Events and VOD

Because a video cache is designed specifically for video, it maximizes efficiency while minimizing latency. Video caches store data in larger chunks than all-purpose caches so they can reassemble the files faster and minimize processing time.

In addition, a robust video cache will store data differently depending on whether the video is a live event or pre-recorded video. During live events, a large audience is not only accessing a video at the same time, the viewers are watching the same segments of the video at essentially the same time. Time is of the essence to minimize latency and keep everyone on the same page (so to speak!). Therefore, a cache that uses memory (RAM) for storage is ideal because it can retrieve video segments, store them, and serve them in a very short amount of time.

With video on demand, viewership is more staggered. Caches need to store multiple segments, if not entire videos, to ensure data is available for subsequent requests. A large cache is the key for getting the best viewing experience with the most bandwidth optimization, so caching on disk works well.

Furthermore, many solutions allow you to store recorded video on the cache when you anticipate high demand for a video. You can pre-position videos minutes, hours or even days before a video is released or announced to ensure 100% of requests are served from the cache.

Caching is a simple set-it-and-forget-it type of eCDN. You size the caches. Deploy them where you need them. Tell user devices how to reach them. And it just works—no client needed.

Most importantly, caching works well for both live events and VOD. The network impact is relatively easy to work out, and while not as deterministic as multicast, it is considerably better than peer-to-peer.

Load-balancing, clustering, and certificates are the most complex elements of caching. But these configurations are much the same as any load-balanced or clustered service. The biggest drawback is the need to place the caches on the network close to users, which depends entirely on the availability of infrastructure that can be used for this purpose.

When Video Caching Is the Wrong Choice

Caching is not the right eCDN for every network, and the cases where it struggles are predictable.

You have no place to put the caches. A cache only helps if it sits close to a concentration of viewers. Sites with a handful of people each, or a fully remote workforce on home connections, give the cache nothing to serve locally.

Your audience is almost entirely live and fully synchronized. When thousands of viewers hit the same segment at the same instant across a multicast-enabled network, multicast moves that traffic more efficiently than caching.

You cannot host infrastructure at the edge. Caching needs somewhere to run, whether a virtual machine, an existing server or an appliance. Where no local compute exists and none can be added, peer-to-peer asks less of the network.

Your bottleneck is the last mile, not the WAN. Caching removes duplicate traffic between the origin and the site. If the constraint is an individual viewer’s home connection, a cache upstream will not fix it.

Most large deployments end up mixing approaches. Caching handles on-demand and mixed workloads, multicast handles fully synchronized live events on capable networks, and peer-to-peer covers locations with no infrastructure to host anything.

Vbrick Edge Caching is an advanced video caching eCDN that replaces expensive infrastructure upgrades with a lower cost, flexible solution. This lightweight, software-only solution runs on your existing infrastructure and supports every modern streaming platform.

Deploy and manage Vbrick Edge Caching 100% behind your firewall and use its built-in security to prevent unauthorized access to your videos. You can also pre-position videos during times of low network activity to avoid spikes in bandwidth during large-scale, VOD events such as pre-recorded executive messages or required trainings.

Because edge caching supports both live and on-demand video, it can serve as your only eCDN. Or you can mix and match it with our other eCDN solutions like multicast and/or peer-to-peer.

• One solution for live and VOD
• No client software or plugins
• Any device, including mobile
• Supports any streaming video source; simultaneous support for multiple sources
• 100% behind the firewall
• Encryption to protect videos in transit (TLS 1.3) and at rest (AES-256)
• Simple, one-time setup
• Scales easily as demand grows
• Centralized management, monitoring & insightful analytics
• VOD pre-positioning
• Self discoverable and self-healing

If you are weighing caching against the other eCDN approaches, the comparison usually comes down to your network rather than the technology. Our eCDN solutions overview sets caching, multicast, and peer-to-peer side by side, and Vbrick Edge Caching covers deployment, sizing, and pre-positioning in detail.