Represents the layer and bandwidth (rate) to which the transmission parameters apply.
Specifically, for a CTP, identifies the layer of the CTP, and the connection rate supported by the CTP.
For a PTP, identifies the layer rate (bandwidth) of the PTP and the characteristic information of the PTP.
For an ATM TP, identifies the layer (and not the bandwidth) of the ATM TP.

Readable by NMS? Yes
Writeable by NMS? No
Invariant? Yes
