Dell 3-DNS, Administrator'S Manual

Page: 112 / 165

Chapter 7
7 - 4
Deciding to use a CDN provider
The 3-DNS Controller is well-suited to serve as the wide-area traffic
manager (WATM) for CDNs that have many of the following attributes:
◆ The CDN provider has a global presence around the edge of the Internet.
◆ The CDN provider outsources a content delivery infrastructure to content
providers.
◆ The CDN provider is the authoritative DNS for the content provider’s
domain, and uses DNS to find a data center with CDN resources at the
edge of the network nearest to the client.
◆ The CDN provider serves all of the content provider’s traffic because the
CDN is authoritative for the content provider’s domain. Content
providers manage this by creating logical groupings of their content
under different domains. For example, an investment firm might have a
CDN host their news content at
news.domain.cdn.net , while they serve
their stock quotes content with quote.siterequest.com from their
corporate data center.
◆ The CDN provider sets its billing rates based on megabits per second.
The CDN provider determines billing by collecting and processing edge
cache and server logs.
◆ The CDN provider has an infrastructure in place to manage the multitude
of geographically distributed devices.
◆ The CDN provider usually establishes some type of service level
agreement (SLA) to ensure that content is being served faster from the
CDN than from the content provider’s origin servers.