Question: In a 5G System (5GS) architecture, when utilizing multiple SCTP associations between an NG-RAN node and an AMF for NG-C signalling, what is the primary purpose of reserving a single pair of stream identifiers over at least one SCTP association?
Option 1: For load balancing across multiple UE-associated signalling streams.
Option 2: Exclusively for NGAP elementary procedures utilizing non UE-associated signalling.
Option 3: To prioritize certain messages over others in SCTP congestion control.
Option 4: For dynamic addition/removal of SCTP associations between the NG-RAN node/AMF pair.
Explanation: Reserving a single pair of stream identifiers over at least one SCTP association is specifically for the sole use of NGAP elementary procedures that utilize non UE-associated signalling. This ensures dedicated resources for signalling not directly related to user equipment, maintaining efficiency and reducing potential congestion from mixed signalling types.