1 Application Orchestration Overview

This chapter provides an overview of application orchestration and describes how Oracle Communications Service Broker performs application orchestration.

About Application Orchestration

Orchestration is the ability of Service Broker to route a session through various applications. Service Broker routes a session sequentially, from one application to another. Each application executes a certain business logic. Every application applies a service on the session before Service Broker routes the session to a next application.

Application orchestration is performed by the Orchestration Engine as follows:

A session arrives to the Orchestration Engine through a network-facing module.
The Orchestration Engine routes the session sequentially through various applications by using application-facing modules. You define the applications that the Orchestration Engine invokes, the order in which the Orchestration Engine invokes the applications, and conditions for invoking applications using a special notation known as the orchestration logic.
After the session passed all applications in the chain, the Orchestration Engine returns the session back to the session control entity in the network.

Figure 1-1 shows an example of how the Orchestration Engine routes a session that arrives from the network through an SCP, then through a SIP application, and then back to the network.

Figure 1-1 Routing a Session Sequentially through Multiple Applications

About Orchestration Logic

Orchestration logic is a notation that you use to specify the applications that the OE invokes, the order in which the OE invokes these applications, and conditions for invoking the applications. You specify an orchestration logic for each subscriber.

The subscriber's orchestration logic is stored as a part of the subscriber's profile. Depending on your deployment of Service Broker, subscribers' profiles and orchestration logic can be defined in:

Home Subscriber Server (HSS), which is the primary user database in the IMS domain. It contains subscription-related information including subscriber applications and subscriber profiles. The HSS OPR uses the Diameter protocol over the standard Sh interface to connect the HSS and select the subscriber profile.
Local Subscriber Server (LSS), which is an on-board implementation of a profile server. The LSS is capable of storing subscriber profiles, including orchestration logic given in the Initial Filter Criteria (iFC) format. The LSS OPR connects the LSS to look up subscriber profiles with the orchestration logic.
Local Subscriber Store or BRM Subscriber Store, which is a database in which subscriber profile data is stored.
Pre-defined list of applications that Service Broker should invoke.

Table 1-1 describes components that the OE uses to retrieve a subscriber profile from a profile server and execute the orchestration logic.

Table 1-1 Service Broker Components Responsible for Retrieving and Executing Orchestration Logic

Component	Description
Subscriber Profile Receiver (SPR)	Connects to the profile server and retrieves the subscriber's profile with the orchestration logic. There are different types of SPRs to connect to different types of profile servers.
Orchestration Logic Processor (OLP)	Retrieves the orchestration logic from a subscriber's profile and executes the orchestration logic.

Figure 1-2 shows how the OE retrieves subscriber profiles and executes the orchestration logic.

Figure 1-2 Retrieving Subscriber Profiles and Executing Orchestration Logic

When a new session arrives to the OE, the OE operates as follows:

The SPR connects to the profile server and retrieves the subscriber profile.
The OLP obtains the orchestration logic from the subscriber profile and triggers the applications as specified in the orchestration logic.
Then the OE releases the session.

About Subscriber Profile Receivers and Orchestration Logic Processors

The OE uses different SPRs to connect to different profile servers. When configuring the OE, you specify the appropriate SPR for the profile used in your system. Depending on the SPR you selected, you need to configure a corresponding Orchestration Logic Processor (OLP).

Table 1-2 explains which SPR you should select and which corresponding OLP you should configure depending on where the orchestration logic is defined.

Table 1-2 SPRs and Corresponding OLPs

To Execute the Orchestration Logic...	Select...	Then Configure...
Stored in a Home Subscriber Server (HSS)	HSS SPR	HSS OLP
Stored in a Local Subscriber Server (LSS)	LSS SPR	SM-LSS
Stored in a Local Subscriber Store or BRM Subscriber Store	Custom SPR	Custom OLP
Defined as a a pre configured list of applications	Default SPR	Static Route OLP

See the discussion on configuring the Orchestration Engine in Oracle Communications Service Broker Modules Configuration Guide for more information about specifying an OPR.

Note:

You can add a new OPR to Service Broker, to connect to other profile sources that exist in the operator's network. Service Broker can apply orchestration logic defined in HSS or any other profile source to the legacy domain.