Ruckus have to flexible downgrade.
If for downgrading from 10.1 to 10.0, though we do config-bakcup of 10.1, we don't restore it to 10.0 because ZD don;t provide d
ownward compatible about config.
If we diretly to install to 10.1, and we need to downgrade 10.0, we only have to do reconfiguration.
It's very inflexible.