Question: In a Telecommunication Network, what is the primary purpose of the 'EMS-Key' parameter in a Charging Data Record (CDR) for emergency services calls?
Option 1: To identify the serving MSC's E.164 number
Option 2: To provide the North American Emergency Services Routing Key
Option 3: To specify the type of emergency service requested (e.g., police, ambulance, fire)
Option 4: To encode the caller's location coordinates
Explanation: The EMS-Key parameter is specifically defined for emergency services calls to convey the North American Emergency Services Routing Key, crucial for routing emergency calls appropriately within the network. It does not relate directly to identifying network elements, specifying service types, or encoding location coordinates.