Description: The 'segment identifier' of the segment from which the remote agent sent the topology message. The value is extracted from the received topology message. Different devices may use different methods for representing the segment identifier. For example, system 5000 NMMs that run multi-segment autotopology use the SrcIndx of the segment as the segment identifier; switches use a computed a value equal to '(256 * s) + p' where 's' is the board, card or slot number and 'p' is the port number on and as seen by the switch sending the topology message; system 3000 NMMs use the lower three bytes of the MAC address of the NMM as the segment identifier. In any case, the 'segment identifier' uniquely identifies the network segment in the remote device from which the topology message was sent.