This read-only integer reports the highest queue depth, in cells, that the channel's ingress queue has reached since it was last reset or created. Admins use this historical high-water mark to see whether the queue has ever come close to its configured maximum (ingrQDepth), which would indicate the channel has experienced significant bursts or sustained congestion. For example, if chanIngrPeakQDepth is consistently close to the configured ingrQDepth, the admin might consider increasing the queue depth or investigating the source of the bursty traffic.