Investigations imply that a proper ignition of target and subsequent burning wave propagation into the cold fuel is strongly affected by the hot spot dynamics. A series of approximation on the hot spot energy balance differential equation leads to an analytical expression for ignition criteria as function of its areal density Hs and temperature Ts which determines ignition boundaries. In these calculations the uniform work done by cold fuel against hot spot pressure is also added. Its tamping effect allows the ignition at new spark parameter sets than a bare DT micro-sphere. By tamping effect growth, from a prolonged to a short effective confinement time, a hole is boring inside the ignition boundary which is sensitive to implosion velocity and become broader at higher values.