Default Cache Management
There are two types of caching that can take place when an asset is routed through Edgecast, which are edge server and user agent (e.g., web browser) caching.
Edge server caching determines whether the requested asset will be cached for a particular POP and for how long. This type of caching determines when an edge server on that POP will check for a new version from the origin server.
User agent caching determines whether the requested asset will be cached on a web browser and for how long. By default, this type of caching determines when a user agent (e.g., web browser) will revalidate the cached asset with the edge server.
If an asset does not have header information, then it will be assigned a TTL of 7 days (i.e., Cache-Control: max-age=604800) when it is cached on Edgecast and by the user agents that requested it.
You can override this default behavior by manually caching and purging assets from Edgecast POPs or through the use of HTTP Rules Engine.
Relevant links: Using Rules Engine to override caching