A table of network layer addresses associated with MAC addresses of active nodes, which are detected to be connected to the concentrator. This table is indexed by the interface it was detected, the board and port the node is connected, the MAC address of the node and an integer index (enumerating multiple network addresses). Note: Only a small implementation determined number of network addresses are stored. The oldest one is discarded, so that the most recent one may be retained. When packet decoding is switched off entries in the network address mapping table may remain present for some time, but no new addresses are added. An network address could appear multiple times in this table (on different board and port) and can appear under different s5CmNetAddrNetIndx over time.