It is a globally distributed network
Reduces asset load time by storing resources closer to end-user
Reduces hosting providers’ bandwidth usage as on each request files don’t have to be pulled from the root host
Provides high availability and low latency due to the distributed nature of the storage
Caching Rules
Azure CDN (Microsoft) uses the Standard Rules Engine
Azure CDN Premium (Verizon) uses the Premium Rules Engine
The below caching rules are only supported with Azure Standard CDN (Verizon & Akamai)
Global
Only one global rule can be created per endpoint
Can override cache headers
Bypass Cache: Don’t cache resources even if cache control headers are present
Override: Override the cache header and set a custom caching duration
Set if Missing: Add cache control header if not added by the client
Not set: Honor the cache header values
Custom
No limit on the number of rules that can be created
The rule can be applied selectively to files extensions and/or all files on a specific path
Can override the global rule
Supports Bypass Cache, Override and Set if Missing Rules
Query String
Ignore query strings
Ignore query strings and cache the resource
This rule has no effect if caching is disabled for the resource
Bypass query strings
Assets with query strings are always fetched from the origin server
Cache every unique URL
Each asset with the query string is considered different and cached
If the application generates a unique query string for every request this mode should not be used as it will result in a low cache hit ratio leading to poor performance