CDN and DNS

The Domain Name System (DNS) is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet, or a private network. It associates various information with domain names assigned to each of the participating entities. It basically serves as the phone book for the Internet by translating human-friendly computer hostnames into IP addresses, but unlike a phone book, it can be quickly updated. 

Content delivery networks (CDNs) are an important part of Internet infrastructure. When a web browser makes a request for a resource, the first step is to make a DNS request. Making a DNS request is a lot like looking up a phone number in a phone book: the browser gives the domain name and expects to receive an IP address back. With the IP address, the browser can then contact the web server directly for subsequent requests (there are actually multiple layers of DNS caching). For a small commercial web site, a domain name may have a single IP address; for large web applications, a single domain name may have multiple IP addresses. 

Physics determines how fast one computer can contact another over physical connections, and so attempting to access a server in Japan from a computer in the United States will take longer than trying to access a U.S. server from within the U.S. To improve user experience and lower transmission costs, large companies set up servers with copies of data in strategic geographic locations around the world. This is called a CDN, and these servers are called edge servers, as they are closest on the company’s network to the end-user. 

Every first user interaction with a website starts with a DNS, but if it goes down, the site can’t be accessed. With a managed DNS solution, the probability of a total network outage is decreased because DNS providers build their networks 100% reliable. Having an “indie” DNS provider, as opposed to a combined professional CDN/DNS provider is a smarter bet because if your combined provider’s network goes down you lose both ways. 

A combined DNS/CDN solution ensures the maximum performance of the website, quickly delivering the content to ensure the highest user experience possible, giving the flexibility when it comes to updating the website. Pairing a CDN with DNS allows you to: Swap to new CDN, Add additional CDN’s, Load balance between Endpoints, Negotiate with coming providers.

[More to come ...]