Each row entry represents a specific Ppp Control Protocol
being run on a specific port from the tmnxPortTable
that is configured for PPP. Entries cannot be created and
deleted via SNMP SET operations; rows are created and
deleted by the agent as the tmnxPortClass and tmnxPortEncapType
values are modified. For any specific link, there is one Link
Control Protocol (LCP) plus one or more Network Control Protocols
(NCP) depending on the type of protocols supported on the link:
ipcp, mplscp, bcp or osicp.