Type 1 RF requires CPAP type of NIV.
Type 2 RF requires BPAP type of NIV.
PEEP=EPAP=CPAP i.e. they all mean the same!
So you can say in Type 1 RF(Hypoxic failure), the pressure we provide is PEEP or just EPAP or CPAP.
For Type 2 RF (Hypercapnic), we provide IPAP as well as EPAP. IPAP is greater than EPAP, PS (Pressure Support is the difference between IPAP and EPAP). For instance if IPAP = 15 and EPAP is 10 then PS = 15-10 i.e. 5cm H2O.