This read-write integer sets the number of static (permanently configured) entries allowed in the bridge's Layer 2 filtering database on this STP bridge. Admins tune it based on available RAM, since the filtering database consumes device memory proportional to this count, and setting it too high can strain a memory-constrained bridge. For example, an admin managing a CX900 bridge with limited RAM might lower this value from its default to free memory for other functions, or raise it to accommodate more manually pinned MAC-to-port bindings.