wfHwCompPpcContextsRegistered 1.3.6.1.4.1.18.3.4.22.4.1.16

This indicates the number of VC's which have registered for HW Compression and are using Packet by Packet Compression (PPC) mode. All VCs/Contexts which register using PPC mode, share 1 HW Context which has been dedicated for use by PPC Vcs.