This read-only Counter tracks the number of unsuccessful attempts to allocate memory from the packet heap in general, independent of any single protocol. An administrator correlates a rise here with simultaneous increases in specific PDU failure counters to confirm a shared heap-exhaustion event rather than a protocol-specific bug. For example, the admin sees ppePacketMemoryFailures jump at the same time as ppeOspfPduMemoryFailures and ppeIcmpPduMemoryFailures, confirming a shared heap exhaustion event affecting multiple protocols.