Diameter Signaling Router Measurements Measurements vSTP Measurements vSTP M3UA Usage measurements VstpTxASPDownAck VstpTxASPDownAck Measurement ID 21009 Measurement Group vSTP M3UA Usages Measurement Type Simple Measurement Dimension Single Description The number of ASP-DOWN-ACK messages sent by the vSTP server. Collection Interval 30 min Peg Condition Each time an ASP-DOWN-ACK message is sent. Measurement Scope NE, Server Recovery No action required.