The number of seconds that a router's Hello packets have not been seen before its neighbors declare the router down. This should be some multiple of the Hello interval. This value must be the same for the remote endpoint. A value of 1 second means that Fast Hello Timers are used on this interface. The ospfPmShamLinkFastHelloMult field is used to determine the Hello interval instead of ospfPmShamLinkHelloInterval.