This object is the current heartbeat timeout, defaulting to 30000 milliseconds, in effect for one specific remote address of this association. Shortening this for a critical backup path lets the association detect that path's failure faster, at the cost of slightly more heartbeat traffic; the value in effect here is what actually determines how quickly a silently dead secondary path gets marked failed. A heartbeat timeout reduced to 5000 milliseconds on a backup path to a critical MGC means a dead backup path would be detected in 5 seconds rather than the default 30, shortening the window where failover would otherwise fail silently.