This read-create value, in seconds, controls how often the Designated Intermediate System sends Level 1 Complete Sequence Number PDUs on a multiaccess network to let other routers detect missing or outdated LSPs. It is only meaningful when this router holds the L1 DIS role for the segment, since only the DIS periodically broadcasts the full LSP database summary. A campus network administrator might shorten csIsisCircL1CSNPInterval from the 10-second default to 5 seconds on a segment with frequent Level 1 topology churn to speed up database synchronization.