Question: What triggers the counting of an Attempted inter 3G-SGSN SRNS Relocation in the old 3G-SGSN, as per Performance Management (PM) measurements?
Option 1: Receipt of a "Forward Relocation Complete" message from the new SGSN.
Option 2: Receipt of a "Relocation Required" message from SRNC, with Target ID indicating Inter SGSN SRNS Relocation.
Option 3: Sending a "Relocation Command" to the UE.
Option 4: Detection of a serving RNC (SRNC) failure.
Explanation: The correct trigger for counting an Attempted inter 3G-SGSN SRNS Relocation in the old 3G-SGSN is the receipt of a "Relocation Required" message from the Serving Radio Network Controller (SRNC), where the Target ID specifically indicates an Inter SGSN SRNS Relocation. This event signifies the initiation of a relocation process, hence an attempt, without guarantee of success.