pdnDot1dTpPortInFrames is a read-only Counter of frames received by this port from its segment, counted only when the frame is for a protocol processed by the local bridging function, including bridge management frames. Admins use this per-port counter to gauge inbound bridging traffic volume and to spot ports that have gone unexpectedly quiet or unusually busy. For example, a port whose pdnDot1dTpPortInFrames counter stops incrementing could indicate the attached device or link has gone down.