Hi Hari,
You seem to explaining what would happen in In based call forwarding, both conditional and unconditional.
I am not familiar with fixed line networks, and would ask the same question as Taru in the context of GSM networks i.e. in the case of the gsmSCF(SCP) setting the T-BUSY DP, would the gsmSCF (SCP) be informed of the T-BUSY DP (through ERBCSM) before conditional call forwarding takes place at the GMSC/VMSC.
Regards
Sanjeev.