Question: In a Diameter-based SLh interface for Control Plane LCS, when a request fails due to a Permanent Failure, how should the Result-Code AVP be conveyed in the response?
Option 1: The Result-Code AVP is always present with a specific error code.
Option 2: The Result-Code AVP is absent, and the error is indicated through a separate Error Message.
Option 3: The Result-Code AVP is optional and may be included depending on the error type.
Option 4: When one of the defined result codes for Permanent Failures is included, it shall be inside an Experimental-Result AVP, and the Result-Code AVP shall be absent.
Explanation: In Diameter-based SLh interface for Control Plane LCS, Permanent Failures are handled to clearly indicate irreversible failure. To maintain consistency with the Diameter base protocol, such failures use an Experimental-Result AVP to state the failure reason, while omitting the Result-Code AVP to avoid duplication and ensure clarity in error communication, ensuring efficient and unambiguous error handling between peers.