Payload compression is available on serial interfaces and it depends on the type of encapsulation. Most payload compression techniques are based on the Stacker or the Predictor algorithm:
Stacker algorithm tries to replace big chunks of data with index in a dictionary. It requires less memory and more CPU, it is more efficient, but less faster.
Predictor algorithm tries to predict the next character. It requires more memory and less CPU, it is less efficient but is faster.
When determining QoS byte counts, legacy QoS uses the data before compression, while the more modern MQC uses the data after compression.
To monitor compression, use: