I’m pasting the definitions of these counters directly from Ericsson Documentation:
CCALLS: “The allocation attempt counters are incremented at every attempt to allocate an SDCCH in a resource type in the cell, regardless of whether the allocation succeeded or failed. Allocation attempts are made at signalling connection setup, at handover and at assignment. ”
Assignment attempts (TASSALL):
The ‘Assignment attempt’ counter (TASSALL) is incremented for the first attempt to change a connection from a signalling only connection to a TCH for speech or data, initiated by reception of ASSIGNMENT REQUEST or HANDOVER REQUEST (cause = directed retry).
At successful assignment attempt the counter is incremented for the target cell.
If the assignment attempt is unsuccessful, independent of reason, the counter is incremented for the cell where the mobile station was tuned to an SDCCH or TCH used for signalling.
Message : ASSIGNMENT REQUEST
HANDOVER REQUEST (cause = directed retry)
‘Assignment complete’ counter (TCASSALL) is incremented for the same conditions as the ‘Assignment attempt’ counter (TASSALL) if the attempt was successful. The ‘Assignment complete’ counter is incremented for the target cell. As TCASSALL is fetched by STS from the same object type as TASSALL they are always synchronized.
I interpret the handover thing as SDCCH handovers which have been enabled in our network, means switching to a new cell during the assignmnet procedure.
Values for a typical hour for a BSC are :
CCALLS =~ 300324
CSMSUP =~ 114790
CSMSDWN =~ 115583
TCASSALL =~ 101542