1. Avaya Aura® Session Manager Documentation, "Administering Avaya Aura® Session Manager" (Release 8.1.3, November 2021), Page 51, Chapter: "Administering Session Manager instances".
The section "Adding a Session Manager instance" states: "On the SIP Entity Details page, in the Port and Protocol Information section, click Add to add the ports on which Session Manager listens for SIP traffic." This explicitly confirms that Listen Ports are defined within the SIP Entity configuration.
2. Avaya Aura® System Manager Documentation, "Administering and Maintaining Avaya Aura® System Manager" (Release 8.1.3, November 2021), Page 487, Chapter: "Elements".
The section "SIP Entity Details fields" describes the configuration page for a SIP Entity. It details the "Port" field where administrators must "Enter the port number that the SIP entity uses to listen for SIP messages." This directly supports the answer.