  Supergiant Fast X-ray Transients are obviously related to persistent
Supergiant X-ray Binaries. Any convincing explanation for their behaviour must
consistently take into account all types of X-ray sources powered by wind
accretion. Here we present a common framework for wind accreting sources,
within the context of clumpy wind models, that allows a coherent interpretation
of their different behaviours as an immediate consequence of diverse orbital
geometries.
