In a standard Avaya Aura® 7 architecture, call routing is centralized through Avaya Aura® Session Manager (SM). Communication Manager (CM) is configured with a SIP trunk to SM. When a call is directed to voicemail (e.g., a coverage path points to a voicemail hunt group), CM routes the call over the SIP trunk to SM. Session Manager then processes the call based on its routing policies. A configured Dial Pattern or Regular Expression matches the dialed voicemail access number and directs the call to the SIP Entity corresponding to Avaya Aura® Messaging (AAM). This is the standard method for integrating applications into the Aura core.

A. Using a direct SIP trunk group between CM and AAM.

This configuration bypasses Session Manager, which contradicts the standard centralized SIP routing architecture of Avaya Aura® 7.

B. Using a direct H323 trunk group between CM and AAM.

Avaya Aura® Messaging is a native SIP application. While legacy integrations existed, the standard protocol for integration in Aura 7 is SIP, not H.323.

C. Using SIP via Avaya Aura® Session Manager (SM), AAM is built as a user with a Communication Profile and registry routing forwards the calls to AAM.

AAM is an application server, not a user endpoint. It is configured in Session Manager as a SIP Entity and Application, not as a user with a Communication Profile.

1. Avaya Aura® Solution Description, Release 7.0 (November 2016)

Page 101, Section: Call flows, Figure 29: Voicemail call flow: This diagram and the accompanying text illustrate the call path from a phone, through Communication Manager, to Session Manager, and then to Avaya Aura Messaging. It explicitly shows Session Manager as the routing core between CM and AAM.

Page 102: "Communication Manager routes the call to Session Manager. Session Manager routes the call to Messaging." This confirms that routing is not direct but mediated by Session Manager.

2. Administering Avaya Aura® Session Manager, Release 7.1 (December 2017)

Page 219, Section: Dial patterns: This section describes how dial patterns are used to route calls. It states, "Use the Dial Pattern page to administer dial patterns that Session Manager uses to route session requests to the appropriate destination." This is the mechanism used to route calls to applications like AAM based on the dialed number.

3. Implementing Avaya Aura® Messaging, Release 7.1 (December 2017)

Page 51, Section: Administering Session Manager for Messaging: This section details the configuration steps within Session Manager, which include creating a SIP Entity for the Messaging server, an Application Sequence, and a Routing Policy with a Dial Pattern that points to the Messaging application. This directly supports the process described in the correct answer (D) and refutes the user-based configuration (C).