Can I transfer calls using the VOIPS.

Yes, but make sure auto call is enabled if you only have 2 locations.

For multiple locations, you may need to enable scripting in the PBX configuration to allow single stage dialing for a seemless transfer function, unless the locations have unique extensions for uniformed dialing. Transfering a call is a function of the PBX, if there is no PBX involved, then it is not possible.