With IPHost Network Monitor you can run simple snmp requests against a IBM device in your network.
pppCPIfIndex
ppp CP If Index
1.3.6.1.4.1.2.6.119.4.2.8.1.1
A unique identifier for a PPP interface running CP. This object is the same as the MIB-II ifIndex object.
Back to ibm-ibmiroc MIB page.
IPHost Network monitor allows you to monitor pppCPIfIndex on IBM device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring IBM switches right now.