Session Expiration Best Practices

Composing SIP Applications 5-1 5 Composing SIP Applications This chapter describes how to use WebLogic Server application composition features, in the following sections: ■ Section 5.1, Application Composition Model ■ Section 5.2, Using the Default Application Router ■ Section 5.3, Configuring a Custom Application Router ■ Section 5.4, Session Key-Based Request Targeting

5.1 Application Composition Model

Application composition is the process of chaining multiple SIP applications into a logical path to apply services to a SIP request. The SIP Servlet v1.1 specification introduces an Application Router AR deployment, which performs a key role in composing SIP applications. The Application Router examines an initial SIP request and uses custom logic to determine which SIP application must process the request. In WebLogic Server, all initial requests are first delivered to the AR, which determines the application used to process the request. WebLogic Server provides a default Application Router, which can be configured using a text file. However, most installations can develop and deploy a custom Application Router by implementing the SipApplicationRouter interface. A custom Application Router enables you to consult data stores when determining which SIP application must handle a request. In contrast to the Application Router, which requires knowledge of which SIP applications are available for processing a message, individual SIP applications remain independent from one another. An individual application performs a very specific Note: The SIP Servlet v1.1 specification http:jcp.orgenjsrdetail?id=289 describes a formal application selection and composition process, which is fully implemented in WebLogic Server. Use the SIP Servlet v1.1 techniques, as described in this document, for all new development. Application composition techniques described in earlier versions of WebLogic Server are now deprecated. WebLogic Server provides backwards compatibility for applications using version 1.0 composition techniques, provided that: ■ you do not configure a custom Application Router, and ■ you do not configure Default Application Router properties.