rldot1sMstpExtPortInternalOperPathCost 1.3.6.1.4.1.9.6.1.101.57.6.7.1.2

The contribution of this port to the path cost of paths towards the spanning tree regional root which include this port. 802.1S-2002 recommends that the default value of this parameter be in inverse proportion to the speed of the attached LAN.