This read-create integer (2-100) is the multiplier the router applies to the Level 1 hello timer to compute the holding time it advertises in its own Level 1 hello PDUs on this circuit. Neighbors use that advertised holding time to decide how long to wait without hearing a hello before declaring the adjacency dead, so raising the multiplier makes the neighbor more tolerant of missed hellos at the cost of slower failure detection. For example, setting csIsisCircL1HelloMultiplier to 10 with a 3-second L1 hello timer tells neighbors to wait roughly 30 seconds before tearing down the Level 1 adjacency on a flaky point-to-point WAN link.