>> Bill Cunningham wrote: >> APEX core data is referred to as datagrams, >> a term denoting the network layer. Surely APEX >> core data has to be packeted, even if not framed. > Dave Crocker wrote: > The term 'datagram' does not specify a particular > level in the communications hierarchy. > It is a mode, not a layer I thought a datagram was at the same layer than a packet, the difference being what they contain: A packet contains data issued from a connection-oriented protocol (such as TCP) from the layer above, when a datagram contains data issued from a connectionless protocol (such as UDP). From what Bill wrote I would interpret that APEX is a transport layer (or possibly above), connectionless protocol. What am I missing here? Michel.