Application, Site, Web, and Games Acceleration

Obviously beyond the specifics of video and audio streaming most publishers are also presenting a vast array of text and images, and often more complex web applications too. Throughout this book I have concentrated on multimedia, largely because that is where my expertise lays but also because the sheer volume of network load that these forms of data generate need to be dealt with a very broad set of skills combining almost every aspect of computer science and telecoms.

For the types of data that result in text, webpages, EPG information, images, and web applications, the challenges are weighted differently. These comprise vast volumes of very small bits of data. Usually that data has a higher value per byte, since you can get quite a few frames of issues and lose quite large chunks of video without losing your audience, but if you lose even a word in a news article, you can completely alter meaning.

This changes the design architecture somewhat. Fortunately, several of the more modern CDNs can help significantly with techniques such as “in-lining” whereby components referenced on a page can be brought into the cached copies of the page wholesale. A good example of this is with a JavaScript (.js) library: often pages use JavaScript libraries by referring to them in the header. These headers can be stored on separate servers to the web content, but a good CDN will load the js in-line into the HTML and then cache the whole code as a single file. In turn this means that only one file is cached and the user's browser simply pulls that single file from the cache, rather than each component from each origin server. So the proximity of the cache reduces latency, and the single session required between the browser and the cache saves an overhead of initiating multiple sessions.

Another common trick is to compress images on the fly, and then update the webpage with less compressed images over time. This helps the user load the page quickly, while over a short time improving the quality of the data presented.

With streaming games, and soon with VR, we will see more and more innovative techniques being introduced to enhance the user's experience.

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