Specifications

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Cisco Internet Streamer CDS 2.0-2.3 Software Configuration Guide
OL-13493-04
Chapter 2 Network Design
Delivery Service
Baseline Groups
A baseline group is a special type of device group that denotes a group of devices for a particular service.
There are three baseline groups:
• Web Baseline Group—Used for web-based content
• Video Baseline Group—Used for video content
• Platform Baseline Group—Used for platform-specific configurations
A device group can be configured as a baseline group. A device can be assigned to a baseline group in
the following three ways:
1. From the Device home page.
2. From the Device Assignment page.
3. From the Device Group Assignment page.
Delivery Service
A delivery service is a configuration that defines how content is acquired, distributed, and stored in
advance of a client request (prefetch), and after a client request (cached). Content from a single origin
server is mapped to a set of devices by means of a delivery service. Content objects associated with a
specific delivery service have a common domain name; in other words, the content in a specified delivery
service resides in a single location on an origin server. Each delivery service maps service routing
domain names to origin servers one-to-one for Service Router DNS interception.
For each delivery service, there is only one Content Acquirer but multiple Service Engines. The location
that has the Content Acquirer for a delivery service is called the root location. Other Service Engines in
the root location that are assigned to the same delivery service can act as backup Content Acquirers if
the configured Content Acquirer fails.
Delivery services form logical routes for content to travel from an origin server through the Content
Acquirer to all the Service Engines in the delivery service. Logical routes for content distribution are
based on the device location hierarchy or Location Tree.
The content distribution route follows the general tree structure of the Location Tree, where content is
distributed from the root of the tree (Content Acquirer) to the branches (Service Engines associated with
the delivery service). A delivery service distribution tree is constructed for each delivery service.
By excluding it from the Coverage Zone file, a Service Engine in a delivery service can be configured
only to forward content and metadata, and not deliver the content to client devices.
Figure 2-2 shows an example of a delivery service distribution tree. The Service Engines participating
in the delivery service are marked in red. Possible content and metadata routes are indicated by red lines.
The actual route may differ among the participating Service Engines as determined by the Service Router
routing method.