I was looking around for a description of what flow-control there is in nanomsg; having remembered words like high-water mark being used in ZeroMQ. I'm interested in knowing under what (if any) circumstances messages would be dropped on the floor. I did see this on http://nanomsg.org/documentation-zeromq.html: "nanomsg uses only TCP's (or equivalent's) buffers to store the data." Does this mean that there isn't any high-water mark concept in nanomsg? (This is probably a good thing, don't get me wrong :) The more general version of this question is: how can avoid data loss in the face of congestion? Does the TCP flow control mechanism serve me here? Thanks. Jason