Question: When an IP Multimedia Subsystem's (IMS) Home Subscriber Server (HSS) is experiencing an overload, what mechanism does it utilize to request reduced traffic from the Application Server (AS)?
Option 1: Including an Overload Control - Open Loop Rate Limiting (OC-OLR) Attribute-Value Pair (AVP) in answer commands
Option 2: Sending a Diameter "Reject" command with an overloaded indication
Option 3: Establishing a temporary TCP connection for overload signaling
Option 4: Broadcasting an SNMP trap to adjacent network elements
Explanation: In IMS, when the HSS encounters an overload situation, it employs a standardized mechanism to communicate with the AS for reducing incoming traffic. This is achieved by incorporating the OC-OLR AVP within answer commands, aligning with guidelines for managing overload situations effectively in Diameter-based networks like those used in IMS architectures.