This read-write INTEGER (1-60) sets the number of BPDUs that must be received on a link before it is considered stable. An admin cares because it affects how quickly a newly active link is trusted as stable for STP purposes versus how resistant that judgment is to a burst of only one or two BPDUs. For example, an admin dealing with a noisy link that occasionally drops a BPDU might raise this count so a single missed BPDU doesn't prematurely mark the link as unstable.