title: ZMQ performance in comparison to UDP multicast
body: <p>What is performance (I mean latency while sending all messages, maximum fan-out rate for many messages to many receivers) of ZMQ in comparison to "simple" UDP and its multicast implementation? </p>
  
  <p>Assume, I have one static 'sender', which have to send messages to many,many 'receivers'. PUB/SUB pattern with simple TCP transport seems very comfortable to handle such task - ZMQ does many things without our effort, one ZMQ-socket is enough to handle even numerous connections.</p>
  
  <p>But, what I am afraid is: ZMQ could create many TCP sockets in background, even if we don't "see" that. That could create latency. However, if I create "common" UDP socket and will transmit all my messages with multicast - there would be only one socket (multicast), so I think latency problem would be solved. To be honest, I would like to stay with ZMQ and PUB/SUB on TCP. Are my concerns valid?</p>