This is the interval of time, in seconds, between periodic transmission of a complete set of CSNPs on multiaccess networks if this router is the designated router at this level, following the resettingTimer behavior. Only the DIS on a broadcast segment sends periodic CSNPs, which act as a database-synchronization checksum listing every LSP the DIS believes should exist, so this interval controls how quickly out-of-sync neighbors get prompted to request any LSPs they are missing. For example, lowering this from a default of 10 seconds to 5 on a segment prone to occasional dropped LSP floods gets any router that missed an LSP resynchronized via CSNP roughly twice as fast.