Abstract: The present invention relates to an apparatus and method for IP switching/routing SDI format image signal through bandwidth splitting and reduction, more specifically, which decomposes image signals consisting of YCbCr type color format entered with serial digital interface (SDI) into Y (luminance) component and C (chrominance) component, or multiple bit slice components; converts the components into IP packets and performs switching and/or routing of the IP packets; extracts Y component and C component or multiple bit slice components from the switched or routed IP packets; and combines the components into SDI format image signal and outputs the combined SDI format image signal. In addition, the present invention provides an apparatus switching/routing image signals through grid based networking, in which broadband switching or routing is performed with multiple narrow band switches or routers by switching or routing image signals through bandwidth splitting and reduction.