is a centered Gaussian process with stationary increments, c > 0 and β > 0 is chosen such that Q(t) is finite a.s., we derive exact asymptotics of P sup t∈[0,T u ] Q(t) > u and P inf t∈[0,T u ] Q(t) > u , as u → ∞. As a by-product we find conditions under which strong Piterbarg property holds.