XcmCommsStackPosition

• Base type Enumeration

A relatively generic description of the current position of this protocol entity (ie, this layer) in a protocol stack. Composed of one or more of the following position descriptors, arithmetically added together: bottom : 1 middle : 2 top : 4 lowerMux : 8 upperMux : 16 Usage: A conceptual row in 'xcmCommsStackTable', which occupies a 'bottom' position in a protocol stack AND has a corresponding row in the 'xcmCommsStackXrefTable', SHOULD have valid references in 'xcmCommsStackXrefIfIndex' (to IETF MIB-II) and 'xcmCommsStackXrefHrCommDevIndex' (to IETF Host Resources MIB). Usage: A conceptual row in 'xcmCommsStackTable' which occupies a 'lowerMux' and/or an 'upperMux' position in a protocol stack SHALL have one (or two) valid corresponding conceptual rows in the 'xcmCommsMuxTable', as the conventionally used 'xcmStack[Lower|Upper]StackIndex' objects take on zero values for multiplexors (thus breaking the graph of the stack layers, without the use of the 'xcmCommsMuxTable'). Note: In many real open systems which are internet attached, IETF IP (connectionless mode) network layer has a position of: a) 'middle' - neither top nor bottom; b) 'lowerMux' - above both OSI LLC (ISO 8802-2) and OSI CONP (CCITT X.25 over LAPB) datalinks; and c) 'upperMux' - below both IETF TCP (connection mode) and IETF UDP (connectionless mode) transports.