I have a Client with some old tapes.

They used Netvault +NDMP filer (*original environment is not available*)

If i want to restore just the NDMP to an external Hard drive how is it possible?

I did some research that seems like Net app Simulator Vm would work, also some say that commvault might work as well. 

Does anyone had experience with this and how to extract data without NDM filer?