Shakir,
If your tenor has software version P103 or higher,then you can reset the password by resetting the unit to factor default. This will delete the entire config including the password, but not the IP information. You do this by connecting to the tenor with a PC and using a serial cable to the console port, and go through the boot up options.
If you do not have P103 or higher, than you will need to contact Quintum to have this reset.
MikeM
mike_voip@hotmail.com