1. Mohorovicic discontinuity-the boundary between the Earth's crust and the underlying mantle; the Mohorovicic discontinuity averages 5 miles down under oceans and 20 miles down under continents.
PAR â Project Authorization Request An approved PAR is needed before official work is begun on a standard project. It serves as the work authorization by the IEEE-SA Standards Board. NesCom examines PARs and makes recommendations to the IEEE-SA Standards Board regarding their approval. An approved PAR is valid for 4 years. The PAR is referred to when the standard is submitted to RevCom for approval.
Topology change Bridge Protocol Data Units (BPDUs) are sent after a topology change has been detected to indicate that the Spanning Tree Protocol (STP) algorithm should be initiated. The format of IEEE 802.1D Bridge Protocol Data Unit (BPDU) is given below. â¢ Protocol ID (2 bytes): Contains the value 0000 for IEEE 802.1D â¢ Version ID (1 byte): Contains the value zero.