According to Cisco’s recent Visual Networking Index, 1.5 billion Internet users will be consuming video content by the year 2016. This is expected to cause IP traffic to reach data levels of 150 petabytes per hour — the equivalent of 278 million HD movies simultaneously streaming. These unprecedented traffic levels will continue to cause major problems for broadband Internet Service Providers (ISPs), who face mounting challenges controlling costs.
Success with cost containment efforts will depend on reducing content delivery transit volume across the network in order to defer infrastructure investments. Typically, these cost reductions are achieved either by leveraging content delivery networks (CDNs) or transparent caching solutions, both of which cache content at the network edge. However, both of these approaches offer only a partial solution when used exclusively. For a more comprehensive solution, a growing number of ISPs are turning to a new strategy: a converged approach, which utilizes CDNs in tandem with transparent caching.
Using CDNs to reduce transit costs has its pros and cons. On the plus side, CDNs:
- Are compatible with a wider range of protocols
- Offer the ability to generate revenue by selling data capacity to content owners
- Are able to maximize the availability of popular content
On the down side, however, CDNs:
- Also require extensive and costly network configurations
- Have limited effectiveness if operators are unable to sign on a large number of the most important content providers
Transparent caching is also a mixed bag. On the one hand:
- It is easier to deploy since it doesn’t require commercial agreements from content providers to use
- Applies more broadly to all content from all providers, regardless of their active participation
On the down side, however, transparent caching:
- Diminishes the amount of control a content owner can exercise over the use and distribution of its property.
- May not work optimally with certain streaming protocols, such as secure, encrypted HTTPS.
A combined approach, using both CDNs and transparent caching, overcomes many of the limitations faced when utilizing only one strategy or the other. CDNs can be used to provide ISPs with extensive and reliable edge caching for participating content owners, while transparent caching can be used to duplicate unmanaged OTT video from content owners who don’t participate in the content delivery network.
ISPs have options when it comes to implementing this combined approach. The simplest method is to run unconnected CDNs and transparent caching systems simultaneously. A partial-sharing approach can also be deployed, using the CDN as the default for managed traffic and transparent caches as the default for unmanaged traffic. More advanced configurations are also available, which create partial or complete sharing of common resources and components.
However, ISPs should also be aware of the challenges that a combined CDN-transparent caching system presents. A converged solution is fairly difficult to implement and optimize, and can create a heavier workload for network managers. As a result, it is necessary to perform a thorough cost-benefit analysis, carefully weigh the cost savings against network performance, and closely track traffic routing, savings, and quality of experience over an extended period of time.
Service providers employing a converged approach will need a unified analytics layer to to deal with advanced resource sharing between caching types and to provided input to routing and control rules. Skytide is uniquely suited to providing such a unified analytics solution. Our patented, highly scalable architecture can process enormous data volumes in real time while enabling multidimensional analysis of network performance data.
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