Читать книгу Understanding Infrastructure Edge Computing - Alex Marcham - Страница 26

One of the best examples of network regionalisation to solve a specific use case as well as address the needs of network operators is the content delivery network (CDN) work done by Akamai Technologies in the late 1990s [5]. Although compared to today the internet and the world wide web it supports were still in their infancy, with both having gained mainstream acceptance only a few years previously, need for the regionalisation of key infrastructure was already beginning to show as the internet became known for distributing new multimedia content, such as images and early examples of hosted video, which began to strain its underlying networks. If left unaddressed, this strain would have limited the uptake of online services by both businesses and home users and ultimately prevented the adoption of the internet as the go‐to location for businesses, essential services, shopping, and entertainment.

The importance of CDNs and of the practical proof point of the benefits of network regionalisation which they represent cannot be understated. By deploying a large number of distributed content caching nodes throughout the internet, CDNs have drastically reduced the level of centralised load placed on internet infrastructure on a regional, national, and global scale. Today, they are a fact of life for network operators; these static caches are widely deployed in many thousands of instances from a variety of providers such as CacheFly, Cloudflare, and Akamai, who reach agreements with network operators for their deployment and operation within both wired and wireless networks which provide last mile network connectivity. This regionalisation of static content, by moving the CDN nodes to locations closer to their end users, improves the user experience and saves network operators significant sums in the backhaul network capacity which would otherwise be needed to serve the demand for the content were it located farther away in an RNDC.

Where infrastructure edge computing diverges from the historical CDN deployment model is in its ability to support a range of use cases which rely on dense compute resources to operate, such as clusters of central processing units (CPUs), graphics processing units (GPUs), or other resources which enable infrastructure edge computing to provide services beyond the distribution of static content. Many CDN deployments do not require significant compute density, nor are many of the existing telecommunications sites where they are deployed (such as shelters at the bases of cellular towers, cable headend locations, or central office locations) which were originally designed to support low‐density network switching equipment capable of supporting the difficult cooling and power delivery requirements which these dense resources impose. Additionally, in many cases infrastructure edge computing deployments bring additional network infrastructure to provide optimal paths for data transit between last mile networks and edge data centre locations and between edge data centres and RNDCs; typical CDN nodes in contrast will usually be deployed atop existing network operator infrastructure at aggregation points such as cable network headends.

It is worth mentioning here, however, that infrastructure edge computing and the CDN are not at all mutually exclusively concepts. Just as a CDN can operate from various locations across the network today by the deployment of server infrastructure in locations such as cable network headends, they are also able to operate from an IEDC. One or multiple CDNs are then able to use infrastructure edge computing facilities as deployment locations for CDN nodes to replace or augment their existing deployments which use the current infrastructure of the network operator.

Although CDNs in many ways pioneered the deployment methodology of placing numerous content caches throughout the internet to shorten the path between the source and destination of traffic, it is important to understand the distinction between a deployment methodology and a use case. The CDN is a use case which needed a deployment methodology that achieved network regionalisation in order to function. As infrastructure edge computing is deployed, CDNs can also be operated from these locations as well. This is an important point that will be revisited later on the subject of the cloud.