Some time blind transfer calls gets failed, When Operator Transfer the Phone to external party (Mobile), Sometimes blind transfer calls gets failed. It's not failing all the times. This issue happening in Remote SRST Sites. We are using CUCM 12.X version . Both PUB and SUB in HO, Remote site(2921 VG) .
User(7821) Phone--->Operator Phone(7975)---CUCM--->H.323(e1)--->PSTN.
We have registered Transcoder resource and applied IN Media resources , In the media resources Software and Hardware resources are allocated.
I need advice , where i can start my troubleshooting.