According to what i under-stand, in case of conditional call forwarding the initial RRBCSM will set T_BUSY ( as u said) and then CONNECT is requested to Calling party “B”, if “B” is busy, then ERBCSM will be sent from SSP to SCP. On receiving ERBCSM with T_Busy set, the SCP will send a fresh connect with “C”‘s number. and call gets forwarded.
But in case of un-conditional call forwarding there will be not wait for any triggers and SCP will send CONNECT (only one CONNECT) with “C”‘s (tobe forwarded) number.
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