Question: In a convergence scenario, what can represent the Subscriber Identifier for a fixed device or Residential Gateway (RG) during establishment of a Subscriber IP session in a fixed broadband access network?
Option 1: Only IMSI received in the Subscription-Id AVP
Option 2: Either Access Line Identifier (via Physical/Logical-Access-ID AVP) or Username (via Subscription-Id AVP)
Option 3: A combination of IMSI and Access Line Identifier, always requiring both
Option 4: The IP Address assigned to the device during the PPP Session
Explanation: In a convergence scenario for fixed broadband access networks, the Subscriber Identifier for devices like RGs can vary. It is not limited to IMSI (which is more commonly associated with 3GPP UEs) but can also be represented by identifiers relevant to the fixed network context. The correct answer reflects the flexibility in identifier usage (Access Line Identifier or Username via Subscription-Id AVP), accommodating different connection types like PPP sessions, as per telecom standards for converged networks.