Step by Step Filtering in Network Layer

The sample codes are a bit confusing, any one can help on how to make filtering on Network Layer step by step, I mean the main steps (which struct and functions of the CNdisApi are used), form the filter sample I learned some thing, like PSTATIC_FILTER_TABLE, then setting m_TableSize, m_Adapter.QuadPart, m_ValidFields, m_FilterAction, m_dwDirectionFlags and others.

Kind regards