ARL syntax

The primary function of an ARL is to direct an end user’s request for an object to the Akamai network. The ARL also contains the object’s caching properties.

Example of an ARL
Serial number
Serial numbers balance the distribution of content on the Akamai network.
Important: The serial number appears in two places in the ARL and should be the same in both fields.
Akamai domain
Non-secure (HTTP) content: a<serial_number>.g.akamai.net.

Secure (HTTPS) content: a248.e.akamai.net.

Typecode
Indicates to the Akamai edge servers the type of coherence mechanism to be used for each object. The two most common options are typecode 7 and typecode f.
7
Typecode 7 indicates that the Object Data field contains an Object ID.

When an Akamai server first caches an object, it creates an identifying entry for the object that contains the object’s source URL and the Object ID, for example 200201171350 - www.foo.com/images/logo.gif. If either of these ARL fields changes in a subsequent request, the Akamai server retrieves the new version of the object from the origin server.

f
Typecode f indicates that the Object Data field contains a TTL value.

The TTL instructs the Akamai servers to send a periodic If-Modified-Since (IMS) GET request to the origin server to verify that the object is still fresh. Valid values for the TTL are [number][s,m,h,d]. For example: 30s, 15m, 5h, 30d.

Customer code
Identifies the content provider and is used for billing and reporting.
Object data
Serves as a coherence or object-freshness mechanism. Depending on the typecode, it contains either an Object ID or a TTL.
URL (absolute)
Specifies the origin or source URL of the object. It is the location from which Akamai servers retrieve the object to cache or refresh it.
Attention: Any domain used in an ARL must be registered through the Akamai Domain Validation tool. If the ARL of an object contains an unregistered domain, Akamai servers will not serve the object.