The primary function of the Avaya Aura® Session Manager (SM) as a SIP registrar is to maintain a location database. When a SIP endpoint sends a REGISTER message, the Session Manager extracts two key pieces of information to create a binding. It stores the user's public address, known as the Address of Record (AOR) or SIP URI, and maps it to the user's current point of contact. This contact information includes the endpoint's current location, specifically its IP address and port, allowing Session Manager to route subsequent incoming calls to that user correctly.

B. User Language preference: This is a user profile attribute configured in System Manager and used for application features, not a core component of the registrar's location binding.

D. SIP endpoint type: While the User-Agent header in a SIP message identifies the endpoint type, the registrar's primary function is to map the user's address to their location, not to store the device model.

E. User Time Zone: This is a user-specific setting managed in System Manager for features like call logging or presence, and is not part of the dynamic registration data.

1. Avaya Aura® Session Manager Fundamentals, Release 8.1.3, January 2021.

Page 23, Section: Session Manager as a SIP registrar: "The registrar function of Session Manager receives SIP REGISTER messages from SIP endpoints. Session Manager uses the information in the REGISTER messages to update the location database with the current location of the endpoint. The location database maps the user’s Address of Record (AOR) URI to the current contact address of the user’s SIP endpoint." This statement directly supports that the SIP URI (AOR) and location (contact address containing the IP address) are stored.

2. Administering Avaya Aura® Session Manager, Release 8.1.3, January 2021.

Page 279, Section: Viewing user registrations: The description of the dumpRegistrations command output shows fields for "AOR" (Address of Record, which is the SIP URI) and "Contact" (which includes the IP address and port of the registered endpoint), confirming these are the key data points stored.

3. IETF RFC 3261 - SIP: Session Initiation Protocol.

Section 10.2, Registrar Processing of REGISTER Requests: "A registrar is a server that accepts REGISTER requests and places the information it receives in those requests into the location service for the domain it handles... It extracts the address-of-record from the To header field of the REGISTER request. The address-of-record is the 'user' that is registering. The registrar also extracts the contact information from the Contact header field(s)." This foundational RFC confirms that a registrar's core function is to bind an Address of Record (SIP URI) to a Contact (location/IP address).