Multivariate ring-model description and the delay operator are used to represent LTI systems with delays in the states, inputs and outputs. By using the concept of mu-Decentralized Fixed Mode (mu-DFM) and generalized Nyquist criterion, it is demonstrated that the steady-state gain information yet remains the only information necessary to assess integral stabilizability (IS), integral controllability (IC), integral controllability with integrity (ICI) and decentralized integral controllability (DIC) of LTI time-delay systems. The conditions involve no approximation of the delay terms. Furthermore, it is demonstrated that a previous assumption on the existence of a stabilizing and stable controller (strong stability) is unnecessary, since it is implicitly satisfied.