Published: 19 August 2016
A content distribution network, also known as a content delivery network, is a large, geographically distributed network of specialised servers that accelerate the delivery of web content and rich media to internet-connected devices. The world's largest content distribution network, owned and operated by Akamai, spans more than 175,000 servers in more than 100 countries around the world.
The primary technique that a content distribution network (CDN) uses to speed the delivery of web content to end users is edge caching, which entails storing replicas of static text, image, audio, and video content in multiple servers around the "edges" of the internet, so that user requests can be served by a nearby edge server rather than by a far-off origin server. To also accelerate the delivery of dynamically generated web content that's difficult or impossible to cache, an advanced content distribution network such as Akamai's uses a range of techniques such as: route optimisation, TCP connection optimisation, and pre-fetching.
Content Distribution Network Benefits
A content distribution network provides substantial benefits to web users, content and application owners, and network service providers:
- For users: Users of websites and web applications delivered through a CDN experience faster page loads and faster transactions than they would in the absence of the CDN.
- For content owners: For content and application owners such as ecommerce sites, media properties, and cloud computing companies, using a content distribution network to improve end users' experience can lower abandonment rates, increase ad impressions, improve conversion rates, and strengthen customer loyalty. Using a CDN can also make an important contribution to web security, for instance by helping to absorb and mitigate a denial of service attack.
- For network service providers: With the explosive growth of online streaming and other rich media services, and higher user expectations about web performance across multiple device types, today's network service providers are finding it necessary to deploy their own content distribution networks. For network operators, deploying a CDN can reduce subscriber churn, facilitate the development of value-added services, reduce traffic on the core network, and enable operators to sell CDN services to enterprises and third-party content owners.
Some things to consider when implementing Edge Caching
- What pages or objects are going being offset to the CDN?
- Who will be responsible for reporting/performance monitoring?
- Cache purging - will it be on a schedule or will someone manually clearing the cache?
- Offset % target - Do you have a site % in mind?
- Perhaps there are parts of the site you may not want to cache, i.e on an ecommerce site this could be your booking engine
- Search results caching? In some cases it pays to cache top search results