This read-only INTEGER identifies the platform type of the node at the remote end of the trunk, one of ipx(1), igx(2), bpx(3), par(4), or unknown(5). An administrator uses it to know what kind of switch is on the other end, since different platform types have different capacity and feature characteristics referenced elsewhere in this MIB, such as the high- versus low-performance node distinction in parNetParmHighTxRate and parNetParmLowTxRate. For example, seeing bpx(3) tells the operator the remote node is a high-performance BPX switch rather than an older, lower-capacity IPX or IGX.